; width:300px; margin:0;"/> Hello, community. Today DeepMind announced a new
achievement of AI
Rating changes for last rounds are temporarily rolled back. They will be returned soon.
→ Pay attention
→ Streams
→ Top rated
| # | User | Rating |
|---|---|---|
| 1 | jiangly | 3640 |
| 2 | Benq | 3593 |
| 3 | tourist | 3572 |
| 4 | orzdevinwang | 3561 |
| 5 | cnnfls_csy | 3539 |
| 6 | ecnerwala | 3534 |
| 7 | Radewoosh | 3532 |
| 8 | gyh20 | 3447 |
| 9 | Rebelz | 3409 |
| 10 | Geothermal | 3408 |
→ Top contributors
| # | User | Contrib. |
|---|---|---|
| 1 | maomao90 | 174 |
| 2 | awoo | 164 |
| 3 | adamant | 163 |
| 4 | TheScrasse | 159 |
| 5 | nor | 158 |
| 6 | maroonrk | 156 |
| 7 | -is-this-fft- | 151 |
| 8 | SecondThread | 147 |
| 9 | orz | 146 |
| 10 | pajenegod | 145 |
→ Find user
→ Recent actions
You can use several words in query to find by all of them at the same time. In addition, if you are lucky search understands word forms and some synonyms. It supports search by title and author. Examples:
305— search for 305, most probably it will find blogs about the Round 305andrew stankevich contests— search for words "andrew", "stankevich" and "contests" at the same timeuser:mikemirzayanov title:testlib— search containing "testlib" in title by MikeMirzayanov"vk cup"— use quotes to find phrase as istitle:educational— search in title
Results
1.
AlphaCode (DeepMind) Solves Programming Problems on Codeforces <img src="/predownloaded/99/08/99083f12762004fb2f7278177262dd577e3f19cd.png" style="float:right; width:300px; margin:0;"/>
Hello, community.
Today DeepMind announced a new achievement of AI. And it is directly related to what we love — programming problems.
They have developed AI capable of solving some competitive programming problems! The future has arrived.
You should read solutions of [user:SelectorUnlimited,2022-02-02], [user:WaggleCollide,2022-02-02], and [user:AngularNumeric,2022-02-02] solutions. All solutions are written automatically. The only input for writing solutions is a problem statement in English.
Details can be read at the link https://deepmind.com/blog/article/Competitive-programming-with-AlphaCode
Apparently, if these accounts would take part in real competitions, then their rating would be about 1300.
<center>
<img src="https://i.blogs.es/a2119c/terminator-2/1366_2000.jpg" style="width:450px;"/><br>
<small>Terminator is ready to take p...
2.
Codeforces EDU: β-testing (Now in English!) <img src="/predownloaded/47/86/4786c2ec901c0b5b490794ca6fd5145f0dcdeae3.png" style="float:right; width: 400px; margin: 0 1em 1em 1em"/>
Hello Codeforces!
In February, in the Russian-language interface, we announced a new educational subsection of the website. It's time to go international!
I am pleased to invite you to test the new section, which so far has the working title EDU. I hope that someday EDU will become a real educational hub for fans of programming competitions. It will be great to have in one place the collected educational content with text and video materials, with selected thematic problems.
At the moment, its functionality is still under development, and here is the current progress and <i>β</i>-testing preview. Write your comments and suggestions in the comments here.
<center style="margin:2.5em;">
<a href="/edu/courses" style="text-decoration:none; font-size:18px; background-color:#01579B; color:white; font-weight:bold; padding:0.5em 1em;">Go to EDU ...
interface, we announced a new educational subsection of the website. It's time
to go international, I am pleased to invite you to test the new section, which so far has the
working title EDU. I hope
3.
Codeforces: Our Steps After DDOS Attack Hello.
As I wrote into a comment, last round we are faced with a strong DDOS-attack which ruined the competition. I don't know who did it, I also don't know reasons to do it. I'm very upset about the situation and ready to make an effort to be prepared for such issues.
I spend a lot of time to be ready for such incidents.
Here are steps you need to do to be ready for unexpected failures:
* Join our telegram channel by the link https://t.me/codeforces_official to read urgent news.
* Be sure that you know the password of your Codeforces account. If you don't remember it, just use <a href="https://codeforces.com/passwordRecovery">the password recovery feature</a>. Please, do it right now.
* I've implemented a minimalistic website for replacing the main site in case of emergencies. Now you can only read problems, view your submissions (without any details), submit codes. Probably, later I'll add some more features, but anyway, the minimalistic version will have only vital fea...
the competition. I don't know who did it, I also don't know reasons to do it.
I'm very upset about
4.
Codeforces Round #648 (Div. 2) Hi everyone!
I would like to invite you to my fifth Codeforces Round, that I set with my friends [user:FastestFinger,2020-06-05], [user:Vivek1998299,2020-06-05] and [user:ridbit10,2020-06-05].
We are excited to bring another contest within a week :D
With that said, I bring to your attention our new [contest:1365] that will take place on [contest_time:1365]. If your rating is less than **2100**, this round will be rated for you; otherwise, you can participate out of competition.
I would really like to thank:
- [user:FastestFinger,2020-06-05], [user:Vivek1998299,2020-06-05] and [user:ridbit10,2020-06-05] for helping with preparing problems and giving new ideas.
- [user:300iq,2020-06-05] for coordinating our round.
- [user:Um_nik,2020-06-06], [user:antontrygubO_o,2020-06-05], [user:ksun48,2020-06-05], [user:Jeel_Vaishnav,2020-06-05], [user:aryanc403,2020-06-05], [user:FlowerOfSorrow,2020-06-05], [user:KonaeAkira,2020-06-05], [user:_Aaryan_,2020-06-05], [user:Ari,2020-06-...
attention our new [contest:1365] that will take place on [contest_time:1365].
If your rating is less than, With that said, I bring to your attention our new [contest:1365] that will take
place on
Announcement of Codeforces Round 648 (Div. 2)
5.
Codeforces Round #646 (Div. 2) Hi everyone!
I would like to invite you to my fourth Codeforces Round, which I have made with my friends [user:FastestFinger,2020-05-29] and [user:TheOneYouWant,2020-05-29]. In terms of problems, it is my favorite among all my rounds.
With that said, I bring to your attention our new [contest:1363] that will take place on [contest_time:1363]. If your rating is less than **2100**, this round will be rated for you; otherwise, you can participate out of competition.
I would really like to thank:
- [user:FastestFinger,2020-05-29] and [user:TheOneYouWant,2020-05-29] for helping with preparing problems and giving new ideas.
- [user:antontrygubO_o,2020-05-29] for coordinating our round
- [user:300iq,2020-05-29], [user:Jeel_Vaishnav,2020-05-29], [user:Ari,2020-05-29], [user:aryanc403,2020-05-29], [user:mahmoudbadawy,2020-05-29], [user:Vivek1998299,2020-05-29], [user:Uzumaki_Narutoo,2020-05-30], [user:Bakry_,2020-05-31], [user:smartnj,2020-05-30] and [user:Nikhil_Medam,2020-05-29]...
, it is my favorite among all my rounds. With that said, I bring to your
attention ournew [contest, With that said, I bring to your attention our new [contest:1363] that will take
place on
Announcement of Codeforces Round 646 (Div. 2)
6.
Polygon: AI-Powered Automatic Tips Hello, Codeforces!
<i>For the new members of the community, I would like to remind you that Polygon (https://polygon.codeforces.com/) is a system developed
and maintained by Codeforces for preparing programming problems. It is there that authors and coordinators develop all the problems for
the rounds. Moreover, I believe a significant (large?) portion of the problems for other competitions is also developed there: various
stages of ICPC, national competitions of different levels, educational problems for various courses, etc.
<b>In 2023, more than 50000 problems were prepared in Polygon (only those for which a package was compiled are counted)!</b></i>
Large language models are becoming an increasingly integral part of our lives, taking over routine and monotonous tasks.
With their help, problems created in Polygon will now have fewer typos and incorrect language constructions.
We have recently implemented three features in Polygon to ease routine tasks:
* Translati...
For the new members of the community, I would like to remind you that Polygon
(https, Hello, Codeforces! For the new members of the community, I would like to remind
you that
7.
[Repost] "Justice may be delayed, but it cannot be absent": New Evidence on
NXIST's Cheating Scandal
[Repost] "Justice may be delayed, but it cannot be absent": New Evidence on NXIST's Cheating Scandal _Original post: [「正义可以迟来但不能缺席」：关于 NXIST 的一些新证据](https://zhuanlan.zhihu.com/p/620297880)_
_Translated by GPT-4 with some adjustment. Please inform me if there are any mistakes._
_All links to the invalid repository have been redirected to the backup repository._
**This article provides a logically complete set of evidence, which does not involve any non-public internet resources, regarding the "suspected cheating" incident involving the ICPC Yinchuan Station and ICPC Shenyang Station in 2021. By discovering the suspected GitHub account ([NaokiLH](https://github.com/NaokiLH), renamed to https://github.com/brokenTarget) of a team member from Ningxia Institute of Science and Technology (NXIST) TS 1 team, Lan Hao, two years ago, and by mining and analyzing the commit records of his algorithm competition repo, we have obtained direct evidence that at least 4 questions from the 2021 Yinchuan regional contest set and at least 6 questions (including scrapped questions) from the 2021 Sh...
[Repost] "Justice may be delayed, but it cannot be absent": New Evidence on
NXIST's Cheating, 2021 ICPC Yinchuan competition?](https://www.zhihu.com/question/459857672), May 10 and May 13 (one week before the competition) to complete the initial
codes for problems B, G, Shenyang Regional Contest offline competition on July 18, no other suspicious
commits appeared., Training Camp 8 on August 9, 2021. Similarly, since it is a paid competition
that requires, before the competition. The substantial amount of new public evidence
indicates that the TS 1 team indeed, behavior in the competition, an insult to programming contests, an insult to
the spirit of ICPC, and an, in their last victory, they have already started preparing for the next
competition. (From the NXIST, many people with the same name). After some investigation (such as [his
algorithmcompetition, of the Yinchuan competition, NaokiLH makes a new round of commits: [88888 ·
NaokiLH/algorithm_trans, win a gold medal in the regional competition.,  to submit, May 21, One week after the end of the Yinchuan competition, NaokiLH makes a new
round of commits, On July 18, the 2020 ICPC Shenyang Regional Contest offline competition
officially began. Team TS 1, On May 22, 2021 (one week after the competition), the uploaded code was deleted
by NaokiLH with a, So when did the official competition of the 2020 Yinchuan take place? May 16,
2021., Video at 1 minute 29 seconds: The competition time for the Shenyang station was
postponed from the, What really gave birth to this article was NaokiLH's algorithm competition repo:, [How to evaluate the ICPC Yinchuan Competition in
2021?](https://www.zhihu.com/question/436832940), competition that requires registration to view the problems, we also provide a
preview of the problem, competition](https://zhuanlan.zhihu.com/p/373983806)
8.
New: Educational Rounds on Codeforces! Hi everybody!
First, I invite you to take part in an official [contest:597]. The fact is, the Codeforces team has made numerous changes to the platform (details are below), and we want to be sure that the basic functionality remained unchanged. This round will have a shortened duration of 1.5 hours, consist of 3 (maybe 4) problems that you might have already seen before. Its purpose is to test the system on the one hand, and on the other hand — to brighten up a Wednesday evening. Of course, the round will be unrated.
Now the main thing. This coming Friday (yes, the 13th of November) Codeforces starts another line of rounds. We called them Educational Rounds. Using my students at the Saratov State University Programmings Competitions Training Center as an example, I regularly notice that even those who have a considerable progress in the results on the rounds often have narrow purview in terms of standard topics and ideas, they are not familiar with many well-known problems ...
New: Educational Rounds on Codeforces!
9.
Who sorry_dreamoon really is Hello everybody. So I was really bored tonight and looked at so many comments being like "[user:sorry_dreamoon,2015-02-18] is X" and then people arguing and disagreeing. Since I had nothing better to do, I decided to finally unravel the truth of who he actually is. Here is the full case and how I actually got to him, hope you enjoy! :D
Selection
------------------
Let's start by the obvious. He managed to get first place in Div2 and he got second in Div1 (would've been first if the scores were static). So what we know is that he is really good.
Let's look at the past 10 Div1 contests. It turns out that only 8 times it happened that someone with a rating of less than 2500 got in top5. This is 8 times out of 50 people being in top5. But he was second and almost first, so he is better than that.
It turns out actually, that in the past 10 Div1 contests, only 2 times it happened that someone with rating less than 2500 got in top3.
Combining this information with [user:sorr...
competition. If you fail, it will be somewhat embarrasing. While you want to
keep your identity private
10.
Hello, ITMO! <img src="https://assets.codeforces.com/images/itmo-logo.png" style="margin:1em 1em 1em 1em; float:right;"/>
Hi Codeforces!
For you, perhaps it was yet another Codeforces round. But not for me. [contest:1066] is the first round tested on new judging servers at ITMO University. And this is not just an update of location. Ta-dam! Now your solutions will be judged on the new Intel i3-8100 processors. And this is not all news. The number of judging servers has increased, which means fewer queues during rounds!
I am pleased to announce that now I live in St. Petersburg, I work at ITMO, and Codeforces is gradually moving from the walls of dear to me Saratov University to ITMO University. The decision to move was not easy for me. My plan is that, based on ITMO, I can focus more on Codeforces development and work on the platform. The number of world champions per square meter is simply overwhelming, and working with a large team of such enthusiasts (and professionals!) of sports pro...
. [contest:1066] is the first round tested on new judging servers at ITMO
University. And this is
11.
Competitive Programming Hall of Fame — cphof.org Hi Codeforces!
Today I'd like to introduce the new [Competitive Programming Hall of Fame](https://cphof.org) project that is available at [cphof.org](https://cphof.org)
#### Background
A long time ago I've noticed that there is no single source of information with the results of previously held large programming competitions. Moreover, plenty of older championships don't maintain their websites anymore, and it becomes hard or even impossible to find any details about them, which is pretty sad. So I've decided to create [Competitive Programming Hall of Fame](https://cphof.org).
#### About the project
Competitive Programming Hall Of Fame is a project created to preserve the history of international championships in competitive programming. This website collects the results of the final stages for both worldwide and regional contests. By international championship we mean a contest consisting ...
Hi Codeforces! Today I'd like to introduce the new [Competitive Programming
Hall of Fame](https
12.
Codeforces Global Rounds Hello!
It is always satisfying and important for me when former contest participants offer their help to the community and support the development of programming competitions. And now I am in a hurry to share the news that thanks to the support of <a href="https://www.xtxmarkets.com/">XTX Markets</a> and the personal participation of Yuri Bedny and Alexander Gerko, we are launching a new line of Codeforces Global Rounds. Hooray!
<img src="/predownloaded/2e/e2/2ee2f0f95f05aae6ca6f47812dae2dc2aabf277b.png" style="width:200px; float:right; margin: 0 1em 1em 1em"/>
Like many of you, I had never heard of <a href="https://www.xtxmarkets.com/">XTX Markets</a> before but it is one of the largest quantitative-driven electronic liquidity providers in the world. I understand little about the financial sector, but with their 34,148 cores and 42 petabytes of usable storage in their research cluster, XTX’s rapid growth and strong market share globally speak for themselves.
So, in 2019, w...
Markets and the personal participation of Yuri Bedny and Alexander Gerko, we
are launching anew line, the personal participation of Yuri Bedny and Alexander Gerko, we are launching
anew line of
13.
Codeforces Sponsored by TON! <img src="/predownloaded/12/a0/12a02d5f16863f9f45bba4c6cd4224f0f2178b94.png" style="float:right; margin: 0 1em 1em 1em; width: 400px;"/>
Hello, Codeforces.
We have exciting news! Look at the logo. See the changes?
Yes, we are happy to announce our new sponsor and partner – the TON Foundation!
We appreciate their support!
The Open Network (TON) is a fully decentralized layer-1 blockchain designed by Telegram to onboard billions of users. The TON Foundation is aimed to further develop and advance the TON Blockchain and its related products for a mass audience.
Andrew Rogozov, founding member at the TON Foundation, says, "<i>We strongly believe in the idea of competitive programming itself, because it is in the TON Blockchain DNA.</i>" The TON Blockchain protocol was designed by Nikolai Durov — who is a two-time ICPC world champion, a three-time IMO gold medalist, a multiple IOI medalist, and a co-founder of Telegram — and other winners of international competitions...
logo. See the changes? Yes, we are happy to announce our new sponsor and
partner – the TON
14.
Codeforces: summing up 2016 year <center>
<img src="http://assets.codeforces.com/images/Happy-New-Year-HD-Wallpapers.jpg"/>
</center>
Somehow it turns out that for me, each coming the New Year means more and more. This is an excellent opportunity to take stock, to breathe fresh air and to go through a kind of catharsis. This is a rare opportunity to be with the family, dress up in Santa Claus and just have fun.
Holidays give me a clear criterion that I do the right things. If during the holidays, I begin to think about it, to recall some deferred ideas, eager to implement something new. So I’m doing right things. My things. And now exactly the same as in several recent years: during New Year holidays I write code for Codeforces, trying new technology or simply I’m making minor changes in testlib. It is necessary to me: at this moment are no deadlines, do not press the obligation. Just now, at 3 am, I can not break away from being able to do something new. I would like to take a moment and realize that spun in ...
15.
About Problem Coincidences Hi.
Of course, there was an unpleasant incident with the problem today. In fact, the problem almost coincided with another problem in the old round, which was hosted 5 years ago.
You, of course, are shocked. You, of course, think that the round should be unrated.
You are wrong. Here's why.
[cut]
We need to clearly distinguish between two scenarios with coincided problems in our rounds.
First. The writer has knowingly plagiarized. This is an outrageous scenario. Such behavior knows no excuse and it is a conscious detriment to our community. Shame on the writer!
Second. The problem was matched unintentionally. The writer was unaware of some old problem. This happens. The coordinator had not seen this old problem before or had forgotten it. We are all human. The round was tested, but the testers did not indicate such a coincidence. Too bad, it happens. Who can we blame for this situation? The writer? Most likely, the writer did a lot of work to prepare the ro...
happens. There is only one way to avoid it — do not hold competitions. Stop
writingnew problems, . There is only one way to avoid it — do not hold competitions. Stop writing new
problems.
16.
Codeforces: Results of 2019 <a style="float:right; display: inline-block; margin:0 1em 1em 2em; max-width: 60%;" href="https://codeforces.com/10years"/>
<img style="max-width:100%" src="https://assets.codeforces.com/images/codeforces-10-years-300.png"/>
</a>
Hi Codeforces!
The platform recently turned 10 years old. We accept your congratulations at <a href="https://codeforces.com/10years">https://codeforces.com/10years</a>.
Please review the progress in 2019 and support the anniversary crowdfunding campaign. Your donation will be a contribution to the future of Codeforces, will
help its development and work. We need resources to continue to host rounds, not to stop developing,
to innovate and to maintain the existing infrastructure.
In 2019, together with numerous writers the coordinators worked on problems: [user:KAN,2020-02-06], [user:300iq,2020-02-06], [user:cdkrot,2020-02-06], [user:arsijo,2020-02-06] and recently joined [user:isaf27,2020-02-06]. And this year,
rounds coordinated by other exper...
personal multi-track competition for Russian-speaking programmers * **XTX
Markets**, Codeforces
17.
Polygon: Warnings for Packages — Incomplete Tests + Statement/Validator Mismatches Hello, Codeforces!
If you're developing problems in Polygon, you might like this image to attract attention.
<center>
<img src="/predownloaded/b4/b6/b4b6e46dd5811c89440ee98bce405e54e3b905c6.png"/>
</center>
<i>For the new members of the community, I would like to remind you that Polygon (https://polygon.codeforces.com/) is a system developed
and maintained by Codeforces for preparing programming problems. It is there that authors and coordinators develop all the problems for
the rounds. Moreover, I believe a significant (large?) portion of the problems for other competitions is also developed there: various
stages of ICPC, national competitions of different levels, educational problems for various courses, etc.
<b>In 2023, more than 50000 problems were prepared in Polygon (only those for which a package was compiled are counted)!</b></i>
We often implement such improvements in Polygon that make the process of preparing a problem more reliable.
These often include var...
.png"/> For the new members of the community, I would like to remind you that
Polygon, For the new members of the community, I would like to remind you that Polygon
(https
18.
I am removing my contest proposal from Codeforces I am removing my contest proposal from Codeforces.
Note: This is a serious blog post. Also, the opinions presented in this blog are my own and not of my friend [user:BiIIy,2018-12-26] who wrote the contest with me.
Today I have removed my contest proposal from Codeforces. I should probably have done this a long time ago. The proposal was made in February, but the problems were written and finished by March, and that is when I opened the contest proposal for review and messaged [user:KAN,2018-12-26]. It is currently December and no progress or development has been made regarding my contest proposal since, so I will be removing it.
I have multiple reasons for removing my contest proposal:
- I have no motivation to host an online contest anymore.
- I am involved in problem setting with two other high school programming contests in my university, and I write, host, and judge another contest for local high schools.
- I have forgotten that I “was in the queue” for writing a...
Codeforces simply gives priority to already trusted problem setters and will
only usenew problem, Codeforces will look for ways to improve their system for the new year.
Specifically, I request
19.
New Code Jam interface: a step back in usability [This post](https://groups.google.com/d/topic/google-code/9SlOptq6gIc/discussion) in Code Jam group
Hi all! This year, Google has again decided to change Code Jam user interface. The new interface has already been used for Code Jam to I/O for Women and Kick Start rounds, and from what I saw, it is even worse than the last year. Let's start.
[](https://i.imgur.com/sACL7ko.png)
This is what I saw when I opened Code Jam main page. This year it uses even longer domain name, [codingcompetitions.withgoogle.com](https://codingcompetitions.withgoogle.com/), and some text seems to be missing. After some investigation, I found that this occurs when a browser is configured to block third-party cookies. I configure my browser this way because I don't want some companies to track me around, and for nearly all sites, this causes no issues. On some sites, blocking third-party cookies causes single sign-on to stop working, but this is understandable. Code ...
New Code Jam interface: a step back in usability, information into the new website, and once more to actually register for the
competition. Otherwise, you, to submit your solutions, you have to register TWICE: once to enter your
information into thenew, competition interface (this screenshot was taken after the round, but it looked
almost like that during
20.
I compiled a list of almost all useful blogs ever published on Codeforces [update: till 09.06.2021] <h3 style="color:red">If there are any blogs that I have missed, please tell in the comment section. Thank you.</h3>
# Mathematics Stuff
- [Number Theory in Competitive Programming [Tutorial]](https://codeforces.com/blog/entry/46620)
- [Number of points on Convex hull with lattice points](https://codeforces.com/blog/entry/62183)
- [FFT, big modulos, precision errors.](https://codeforces.com/blog/entry/48465)
- [Number of ways between two vertices](https://codeforces.com/blog/entry/19078)
- [Mathematics For Competitive Programming](https://codeforces.com/blog/entry/76938)
- [FFT and NTT](https://codeforces.com/blog/entry/19862)
- [Burnside Lemma](https://codeforces.com/blog/entry/51272)
- [Number of positive integral solutions of equation 1/x+1/y=1/n!](https://codeforces.com/blog/entry/76836)
- [On burnside (again)](https://codeforces.com/blog/entry/64860)
- [Simple but often unknown theorems/lemmas/formula? Do you know?](https://codeforces.com/blog/entry/55912)
- [Probabili...
!)](https://codeforces.com/blog/entry/84017) - [Competitive Programmer's
Handbook — anew book on, /47402) - [Introduction to New Data Structure: Wavelet
Trees](https://codeforces.com/blog/entry
21.
New coordinator presents Codeforces Round #327 Hello, dear participants of Codeforces community!
Starting from Codeforces Round #327 I'll be the new coordinator and will manage preparation process for all regular Codeforces rounds and other contests held on this platform. I'll do my best to increase the quality of contests we offer you, though [user:Zlobober,2015-10-24] already raised this bar high. Let's cheer him once again, for all the great job he had done!
Tomorrow round will be held using the problems of Moscow team olympiad for high-school students. Do not be tricked by the word "school" — there will be a gold medalist of IOI 2015 participating and some candidates to this year Russian IOI team, meaning the level of the problems will be appropriate. I am sure everyone will find an interesting problem to enjoy.
The problemset was prepared by the team of Moscow authors (list is incomplete): [user:Zlobober,2015-10-24], [user:romanandreev,2015-10-24], [user:_meshanya_,2015-10-24], [user:wilwell,2015-10-24], [user:g...
New coordinator presents Codeforces Round #327, official competition., the new coordinator and will manage preparation process for all regular
Codeforces rounds and other
Announcement of Codeforces Round 327 (Div. 1)
Announcement of Codeforces Round 327 (Div. 2)
22.
[Tutorial] GCC Optimization Pragmas ## Introduction
A while ago [user:ToxicPie9,2021-10-27] and I made and posted this meme:
To my surprise, many people are quite confused about it. In fact, I realized there are a lot of misconceptions about pragmas. Most C++ users on Codeforces put a few lines of pragmas at the start of every submission. However, I believe many of them don't fully understand what they're doing or how pragmas work; the only thing people seem to think is that "add pragmas -> code go brr".
Pragmas are a form of the dark arts that are feared and used, both correctly and incorrectly, by lots of competitive programmers. They are widely believed to make your code much faster, but sometimes may lead to slowdowns and even runtime errors on certain platforms. In this blog, I will explain the effects of `#pragma GCC optimize` and `#pragma GCC target`, how they work, and how you should and shouldn't us...
23.
Codeforces Round #508 (Div. 2) Hi everyone!
It has been almost 2 years since I joined Codeforces, and it has been a great journey as a contestant. I now try to take a shot at problem-setting with my friend [user:Mahir83,2018-09-05].
With that said, I bring to your attention my new [contest:1038] that will take place on [contest_time:1038].
If your rating is less than 2100, this round will be rated for you; otherwise, you can participate out of competition.
I would like to thank [user:Mahir83,2018-09-05] for his help with preparing problems, [user:_kun_,2018-09-05] & [user:300iq,2018-09-05] for coordinating my round and [user:Um_nik,2018-09-05], [user:senek_k,2018-09-05], [user:gritukan,2018-09-05], [user:Vovuh,2018-09-05] & [user:BledDest,2018-09-05] for testing my problems. I would also like to thank [user:MikeMirzayanov,2018-09-05] for Codeforces and Polygon platforms.
You will be given 6 problems and 2 hours to solve them. Scoring distribution will be announced later.
Good luck!
**UPD:** Scorin...
-05]. With that said, I bring to your attention my new [contest:1038] that will
take place on, With that said, I bring to your attention my new [contest:1038] that will take
place on
Announcement of Codeforces Round 508 (Div. 2)
24.
If you ask me how to improve your algorithm competition skill, I will give you the link of this blog. In recent one year, I don't know why but there are many people sending messages to me for asking similar problems. So I decide to create this blog.
In the beginning, I must say, you may feel disappointed after reading this blog. Because I don't have any special tips. My study method has wasted me many many time.
There are some basic points I think you have known.
1. **Practice, practice, and practice.**
I take so many time to think and solve problems. I think I do it 5 hours a day on average.
2. **Make friends with many awesome people.**
I know many awesome people. For example, [user:arosusti,2015-02-24], [user:kelvin,2015-02-24], peter50216([user:0O0o00OO0Oo0o0Oo,2015-02-24]), [user:seanwu,2015-02-24], [user:Shik,2015-02-24], [user:takaramono,2015-02-24], [user:tmt514,2015-02-24], ...
If I have some problems that I can't solve in few weeks, I can almost get solution from my friends.
Then I say what I do for training myself.
When I do problems. There are two possi...
If you ask me how to improve your algorithm competition skill, I will give you
the link of this, change the strategy. And when I feel I can't solve problems anymore from a
judge. I will find anew judge, problems anymore from a judge. I will find a new judge and continue to do the
same thing.
25.
Codeforces: Results of 2017 <img src="/predownloaded/e4/09/e40915ee54c5991b91098756a90270d94be893b3.jpg"/>
Happy New Year, Codeforces!
I hasten to wish the whole community (and including me) correct programs, sudden insights, beautiful ideas and interesting problems!
I hope that you have met the new year at least as fun as I am. Have you had enough sleep after New Year's Eve? This year, the traditional post summarizing the past year, I sat down to write only on January 1, 2018. I hope that I will not have to sum up the whole year.
This post is important to me, since it draws a line to all the work done by the Codeforces team and the entire community in 2017. Many thanks to the team: all of the achievements listed below are the result of joint efforts. We did an excellent job! The community must know its heroes. In 2017, [user:MikeMirzayanov,2018-01-02], [user:KAN,2018-01-02] (problem coordinator), ~gritukan,2018-01-02 (second problem coordinator), ~netman,2018-01-02 (ex-second problem coordinator), ~k...
Happy New Year
26.
Returning to In-Person GCJ/Hacker Cup Finals In the past, most elite programming competitions (e.g. IOI, ICPC, TopCoder Open, AtCoder World Tour, GCJ, Hacker Cup) have held their final stages in person. In 2020 and 2021, however, most of these contests were moved online. This was unfortunate, but understandable given the circumstances: in 2020, the state of the pandemic clearly did not allow for extensive travel, and while the dangers decreased by late 2021 as a result of rising vaccination rates around the world, there was still sufficient uncertainty to justify holding events online in 2021.
This year, however, both Google Code Jam and Meta Hacker Cup have committed to hosting online finals. [**UPD:** Meta has retracted its commitment to a virtual finals, so it seems that the plans for MHC are still up in the air.] I believe that this is a highly unnecessary precaution--there is plenty of evidence showing that it is possible to successfully run an in-person event in 2022. Notably, TopCoder has committed to hosting the...
finals will become the new default, and it's unlikely that in-person
competition will ever return to, the new default, and it's unlikely that in-person competition will ever return
to these events. I
27.
Introducing Competitive Programming Academy Hi all!
I'm proud to announce **Competitive Programming Academy**, my new programming competition training community.
Though the broad objective of CPA is to help people grow as competitive programmers, there are three specific goals I hope to achieve with this program:
1. To provide a programming competition community focused specifically on training and growth. There are many existing communities that work well for discussing programming contests, but I think having one emphasizing training will make it easier for people to ask questions without fear of being ignored (or downvoted). Of course, the other advantage of asking questions there is that I'll be around to answer them. Additionally, my hope is that having a community with which to train is likely to help people who don't have other competitive programmers around locally find motivation to grow.
2. Helping people create training plans and find helpful resources to use while practicing. While I'm not convinced t...
Hi all! I'm proud to announce **Competitive Programming Academy**, my new
programming, I'm proud to announce **Competitive Programming Academy**, my new programming
competition training
28.
The Toxic Mindset in Competitive Programming and How to Fight It #### Introduction
Rating is a great measure of skill and a nice way to observe progress by comparing yourself to your past self and seeing where you stand in the community. As great measure as it is, there are a lot of problems that come with it. They have nothing to do with how the rating system works but rather with how human beings function. In this blog post, I will talk about some of the most pressing personal problems that come up with rating and try to provide some advice on how to solve them, speaking from personal experience and from the experience of a lot of other people I know.
#### Associating self-worth to rating
This is, in my opinion, the most significant problem people face, and it also pretty much contains all the following problems as a subset. It's extremely easy to fall into this rabbit hole since, as a competitive programmer, it only feels natural to associate our rating with intelligence and, respectively, our intelligence with self-worth. Why is this su...
are a great way to practice in a competitive environment, learn to deal with
thecompetition stress, horrible — "I got just +100, but if I got five more, I would have gotten a new
rank! Why couldn't I have, - Did you get a negative delta? That means you learned something new, you
gained experience, you
29.
On organizing new Competitive Programming Competitions with awards Hello everybody!
As you already know, some high profile competitions, such as GCJ and TCO have been officially discontinued and there is clearly a lack of competitive programming contests with awards for the very best performers.
Given the size of the community we have here on Codeforces and on other places too, I think we can use our expertise and our networking to create a new series of competitions (and possibly in the future an organization to help competitive programming grow worldwide) to make up and even pass the existent competitions in prestige and awards. After all, the platform which will be used won't even matter that much, as I see it as a team effort to bring competitive programming to a higher standard in terms of prizes in competition.
For example, [Codeforces got $125k](http://codeforces.com/10years/supporters) when people donated for the 10 year badge, which is a lot of money used for expenses such as keeping the servers up, paying problem setters and paying...
On organizing new Competitive Programming Competitions with awards, on other places too, I think we can use our expertise and our networking to
create anew series of, use our expertise and our networking to create a new series of competitions
(and possibly in the
30.
ICPC World Finals 2018 <img src="/predownloaded/de/f3/def309578bab3ca770ea7262a4135f8f1ea50545.jpg" style="margin: 0 0 0 1em; float: right;">
ACM-ICPC World Finals 2018 will begin on <a href="https://www.timeanddate.com/worldclock/fixedtime.html?msg=ACM+ICPC+2018+World+Finals&iso=20180419T10&p1=33&ah=5">April 19, 2018 at 2:00 (UTC)</a>.
This event is the main event of the year in the world of sports programming!
In the past 20 years alone, ICPC participation has increased by more than 2000%. Last year, ICPC Regional
participation included 49,935 of the finest students and faculty in computing disciplines from 3,098 universities in 111 countries on six continents. A record 53,446 students and 5,411 coaches competed in ICPC and ICPC-assisted competitions last year, setting new records in participation.
Codeforces wishes the teams to show a vivid and interesting contest. We wish to find beautiful solutions, write without bugs and enjoy many accepted problems!
Links:
* <a style="font-weight: bol...
competed in ICPC and ICPC-assisted competitions last year, setting new records
in participation
31.
Testlib: Opts — parsing command line options Hello!
It seems to me that over the past few years I have been writing something right while all normal people
are celebrating the New Year. It's my tradition now! Actually, most of the core functionality of
Codeforces was written on the New Year holidays of 2010: authorization, blogs, basic support for competitions.
Perhaps I want to spend the next year with interest improving something in the Codeforces infrastructure
(yep, how you celebrate the New Year — so you will spend it). Or maybe it's just that it's not
necessary to work on New Year's and I'm doing not what you need right now, but what would be
nice to do someday.
This time I took a little time to add support for parsing command line parameters in
<a href="https://github.com/MikeMirzayanov/testlib">testlib</a>. I really don't like to
write such lines of code `int n = atoi(argv[3]);` in generators. Actually for several reasons:
* it is unsafe that the 3rd command line parameter may be absent;
* It is ...
normal people are celebrating the New Year. It's my tradition now! Actually,
most of the core, people are celebrating the New Year. It's my tradition now! Actually, most of
the core functionality
32.
Codeforces: Results of 2018 Hi Codeforces!
February 2019 is already on the calendar, which means that I was late with the report for 2018. Better late than
never! Let's remember last year.
In 2018, [user:_kun_,2019-02-05], [user:300iq,2019-02-05] and [user:arsijo,2019-02-05] joined the team of coordinators. The work of the coordinators is headed
(and is the coordinator of the coordinators) [user:KAN,2019-02-05]. I really hope that a more measured schedule of preparing rounds by
a large team of coordinators will give a better insight into the contests. The main innovations in the platform are implemented
by me and the developers [user:kuviman,2019-02-05], [user:fcspartakm,2019-02-05], [user:MaximShipko,2019-02-05]. Great work on the organization of events and
prizes mailing was done by [user:gKseni,2019-02-05].
Special thanks to the writers of the problems and testers. It is your content that charges the community with life and unites
all of us. Thank you for the problems!
And now let's summarize...
held with their help, thank you! * **VK**, VK Cup — team competition for young
Russian
33.
The Psychology of Competition Participating in a big competition like IOI or ICPC can be intimidating, the worst thing that might happen to you is that you manage to get nervous enough to enter that adrenaline-fueled fight or flight state, you start feeling that you need to get out of the contest fast. An easy bruteforce solution that would take you 2 minutes to code in a normal environment suddenly requires 10 minutes, or at least that's what happened to me the last 3 major competitions I participated in (APIO 2014, IOI 2014 and APIO 2015), while it wasn't very noticeable in APIO 2014 -I quickly forgot about it because it was my first medal a bronze one- and I blamed that state on sickness in IOI 2014, after APIO 2015 it became clear to me that I'm making the mistakes over and over.
If you're really new to competitive programming, someone who doesn't really care much about the result, or someone who's trained since the age of 6 you probably won't relate to these issues, but after I've done some research I reali...
The Psychology of Competition, If you're really new to competitive programming, someone who doesn't really
care much about the, Participating in a big competition like IOI or ICPC can be intimidating, the
worst thing that might
34.
About the Round 382 Good afternoon!
I've decided to share my thoughts on the round 382.
Of course, it turned upset not only to me, but also to the round coordinator [user:GlebsHP,2016-11-28].
In this round the main negative feedback were caused by two problems: [problem:735D] and [problem:735C].
Regarding [problem:735D]. I do not share the criticism to this problem. In fact, to solve it would be nice to be familiar with <a href="https://en.wikipedia.org/wiki/Goldbach's_conjecture"> Goldbach's Conjecture</a> and better with <a href="https://en.wikipedia.org/wiki/Prime_number_theorem">Prime Number Theorem</a>. These facts are medium-popular in the world of programming contests. Familiarity with them is useful, gives useful insight into primes. It is important: in this problem it was necessary to perform a simple, but nevertheless, additional step to find solution. It seems to me that it's okay to use problems that have a reduction to some popular and semi-popular topics. Otherwise, it is th...
self-development and a desire to get a fan from the competition. None of these
goals encourage search
35.
New on Codeforces: Allowed Programming Languages Customization for Mashups/Private Trainings Hello!
Codeforces supports a wide range of languages. Just yesterday I supported Java 11.
On the other hand, my website is not only just open public rounds and trainings, but also an advanced system of groups, custom domains and mashups. This ecosystem makes it possible to conduct private trainings, local contests/olympiads, provides the work of computer science clubs, and so on.
Sometimes you ask me to somehow limit the languages that can be used in a particular contest. For example, an official competition is held that does not support Rust. Or this contest is a practical session specifically for classes in Python.
Now you can configure allowed programming languages (more precisely, their groups) for your mashups and private trainings. Thanks for the help to [user:geranazavr555,2019-10-22] who helped to realize this opportunity!
Here are some screenshots of how it looks in action.
<center>
<img src="/predownloaded/49/19/4919e2326a4b99b50aee02f92487a4bb99dbd1f7.png"...
New on Codeforces: Allowed Programming Languages Customization for
Mashups/Private Trainings, example, an official competition is held that does not support Rust. Or this
contest is a practical, , an official competition is held that does not support Rust. Or this contest
is a practical session
36.
Codeforces Month of Blog Posts (win $300) **TL;DR:** Write an interesting CodeForces blog post until February 15th and win $300.
**UPD: Second place will receive $50.**
**UPD2: Competition is over, The results are available [here](https://codeforces.com/blog/entry/113041).**
I am a huge fan of CodeForces and specifically CodeForces blog posts! There are tens and hundreds of gems posted on this platform throughout the years. Thankfully, recently there was added the [catalog](https://codeforces.com/catalog) page where a lot of cool articles can be found. Personally, if I want to remember some classical algorithm, I would go to websites like [cp-algorithms](https://cp-algorithms.com/), but CodeForces is the place where new or rare stuff is born, where new points of view emerge. I think it is one of the most valuable functions of this website, and I would like to facilitate its growth. I know that many people have cool ideas in their minds that they came up with or maybe something that is known only in their community on ...
: Second place will receive $50.** **UPD2: Competition is over, The results are
available [here
37.
[CONTEST OVER] MIT Informatics Tournament (M(IT)^2) 2024 **UPDATE 3**: There was a typo in the registration link that led to the pre-registration form. If you filled that out, please fill out our actual [registration form](https://mitit.org/Registration). Note that with the contest **within 24 hours**, we cannot guarantee we review all applications in time. Please submit ASAP if you would like to be considered. Apologies for the inconvenience.
**UPDATE 2: The contest is in less than a week! Note that we changed the venue from the MIT Media Lab to [Huntington Hall (10-250)](https://whereis.mit.edu/print_window.html?zoom=16&lat=42.359674020000014&lng=-71.09201372&maptype=mit&q=10-250&open=object-10). There will be thousands of dollars in cash prizes and also exclusive merchandise!**
The schedule for contest day is below. We are excited to see everyone!
- **8 AM — 9 AM:** Contestants check-in + breakfast
- **9 AM — 10 AM:** Opening Ceremony + Last minute team formation
- **10 AM — 10:30 AM:** Buffer time as teams ar...
are running a new programming competition — the MIT Informatics Tournament,
aka M(IT)^2, ]), current students at MIT, are excited to announce that we are running a new
programmingcompetition
38.
Dasha Code Championship Finals and Mirror Round 588 Announcement Hello everybody! A new round is upcoming and I'm honored to be its author. The round will first appear as the onsite for Dasha.AI Code Championship and later we will hold a rated mirror. Everybody is welcomed to participate in Codeforces and I wish good luck for people in Saint Petersburg and Novosibirsk.
Using the opportunity, I want to thank:
- [user:mnbvmar,2019-01-02] for helping in the preparation of a great part of everything. Really, without you, I wouldn't do it.
- [user:300iq,2019-01-02] for coordination and help with preparation.
- As always, [user:MikeMirzayanov,2019-01-02] for taking care of international competitive programming and making such great platforms as Codeforces and Polygon.
- [user:KAN,2019-09-24], [user:zscoder,2019-09-24], [user:Lewin,2019-09-24], [user:JeffreyHo,2019-09-24], [user:Darkstalker,2019-09-24], [user:Darko,2019-09-24] and [user:Gtaumaturgo,2019-09-24] for testing the problems and great advice.
- [Dasha.Ai](https://dasha.ai/en/) for an or...
Hello everybody! A new round is upcoming and I'm honored to be its author. The
round will first
Announcement of Codeforces Round 588 (Div. 1)
Announcement of Codeforces Round 588 (Div. 2)
39.
2nd Universal Cup Announcement Hello everyone, we are happy to announce that the 2nd Universal Cup has started officially.
The Universal Cup is a non-profit organization dedicated to offering training resources for competitive programming teams. Our website is [https://ucup.ac/](https://ucup.ac/) (in English and Chinese).
In the previous season, over 750 teams from more than 300 affiliations all over the world, registered and participated in a total of 22 stages, encompassing contests from Asia, Europe, and America.
With the permission of contest setters and without involving copyright disputes, the Universal Cup will hold mirror contests for some undisclosed competition sets. It is expected to hold at least 20 contests in this season. We will simulate the actual situation in the competition, executing the board freeze in the last hour. At the same time, we will provide an overall rating board, which will help the team to make a reasonable assessment of itself.
Over the past few weeks, the committee has...
will hold mirror contests for some undisclosed competition sets. It is
expected to hold at least 20
40.
Yandex.Algorithm 2017 We are announcing the annual Yandex.Algorithm 2017 championship! This is a great opportunity to compete with the strongest programmers of the world, win a fancy T-shirt, visit Yandex office or even receive some serious money prize.
<br />
[cut]
<center><h3><a href="https://contest.yandex.com/algorithm2017/schedule/">Complete schedule</a></h3></center>
In order to take place in the main part of the competition you must participate in at least one of the Warm-Up round ([April 22nd, 16:00 Moscow Time](https://www.timeanddate.com/worldclock/fixedtime.html?msg=Yandex.Algorithm+2017+Warm-up+round&iso=20170422T16&p1=166&ah=1&am=40)) and Qualification round ([April 29nd or 30th, virtual participation](https://www.timeanddate.com/worldclock/fixedtime.html?msg=Yandex.Algorithm+2017+Qualfication+round&iso=20170429T00&p1=166)) and solve at least one problem in some of them.
...
place in the main part of the competition you must participate in at least one
of the Warm-Up round, The Final round of the competition will take place on July 18th in Yandex
Moscow office. Aside from
41.
My strategy at AtCoder & CS Academy There's been much controversy lately about the late submission strategy not penalized by scoring systems of AtCoder and CS Academy.
Most of the relevant discussion happened earlier at http://codeforces.com/blog/entry/53431 and http://codeforces.com/blog/entry/53449.
I have a lot of thoughts on the topic, so I've decided to share them in a separate blog post.
I really like the strategic part of programming competitions. Of course, problem solving is more important.
But every contest consists of multiple problems, so there has to be a way of comparing participants which performed better at different problems.
There's a huge variety of scoring rules, and I find it truly amusing.
The "submit after solving all problems" strategy looks widely attributed to me now, mostly due to [user:Petr,2017-07-24]'s remarks regarding my participation in AtCoder contests.
In my opinion, it's wrong for multiple reasons.
A closer five-word description of my strategy is "implement after solvin...
say addicted, to switching between problems often, and it seems in this case I
come up withnew
42.
Codeforces Round #523 (Div. 2) Hi everyone!
I would like to invite you to my second Codeforces Round, which I have made with my friend and Snackdown partner [user:Jeel_Vaishnav,2018-11-21].
With that said, I bring to your attention our new [contest:1061] that will take place on [contest_time:1061]. If your rating is less than 2100, this round will be rated for you; otherwise, you can participate out of competition.
I would really like to thank [user:Jeel_Vaishnav,2018-11-21] for his help with preparing problems, [user:_kun_,2018-11-21] for coordinating our round and [user:Um_nik,2018-11-21], [user:gritukan,2018-04-08], [user:Aleks5d,2018-11-21], [user:Keyuuuu,2018-11-21] & [user:Mahir83,2018-11-21] for testing the problems. I would also like to thank [user:MikeMirzayanov,2018-11-21] for Codeforces and Polygon platforms.
You will be given 6 problems and 2 hours to solve them. Scoring distribution will be announced later.
Link to [My Coding Library](https://codeforces.com/blog/entry/61836) for those int...
attention our new [contest:1061] that will take place on [contest_time:1061].
If your rating is less, With that said, I bring to your attention our new [contest:1061] that will take
place on
Announcement of Codeforces Round 523 (Div. 2)
43.
Rescheduling of World Finals 22&23 After a few days of waiting, ICPC finally sent out an announcement concerning the recent situation in Middle East:
<spoiler summary="ICPC Email Content">
Friends,
The ICPC Code of Ethics defines us as a global community. It reminds us of who we are. It provides healthy boundaries to solve problems together to the benefit of future problem solvers. In goodwill, following the Golden Rule, putting people first, and solving problems to grow stronger together, we ask for your consideration to deal with the challenge at hand. We have run out of options to conduct the 2023 ICPC World Finals as planned November 12-17, 2023.
The 2023 ICPC World Finals in Sharm el-Sheikh, hosted by AASTMT, must be rescheduled due to extraordinary circumstances that affect many participants. We are working with AASTMT to identify new dates and plan to announce them no later than January 2024. The targeted new dates are late 1st quarter or early 2nd quarter of 2024. Starting next Friday, November ...
working with AASTMT to identify new dates and plan to announce them no later
than January 2024. The
44.
pol2dom: Convert problems from Polygon to DOMjudge TL;DR: I am advertising [pol2dom](https://github.com/dario2994/pol2dom): a tool to convert a set of problems prepared in Polygon into a DOMjudge contest.
The whole process is automated: downloading the Polygon package, converting it into a DOMjudge package, and uploading the DOMjudge package to a DOMjudge server.
If you are organizing a contest that uses DOMjudge, I invite you to give `pol2dom` a try.
#### Long story
[Polygon](https://polygon.codeforces.com/) is the platform used to prepare problems for Codeforces rounds (and, at least one year ago, for Codechef rounds). It has [many issues](https://codeforces.com/blog/entry/90914) but, as far as I know, it is the best platform for preparing competitive programming problems. It has a large number of checks that catch common mistakes, it is hosted online, it allows a coordinator to quickly review the preparation, and so on. As everyone, I would like to see Polygon improve (for example, with a decent UI), but there's nothing ...
regional contests (NWERC, SWERC, NAC, SPPC, and others), at the world finals,
and in thenew, ), at the world finals, and in the new [Universal Cup](https://ucup.ac/). It is
rather popular
45.
A look at Competitive Programming post-hibernation Hello friends!
As I've recollected in a previous [post](https://codeforces.com/blog/entry/97566), I am an old competitor who hadn't really participated since ~2014, and recently got a bout of nostalgia to return to Competitive Programming. So, I did a couple Topcoder SRMs, suffered through some SNWS rounds, participated in [three regional 5hr competitions](https://contest.yandex.ru/3QF2021) on three consecutive days, and dozed off at every Codeforces contest I tried to wake up for.
A lot of things are still the same as 8 years ago: [user:tourist,2022-01-26] is still at the top, grey coders still ask for how many minutes to solve a problem before reading the editorial, Russian university teams [continue winning](https://icpc.global/worldfinals/results) ACM ICPC, and Snarknews never gives up on his alternate competition formats. But in this post, I want to focus on the new patterns that emerged since my last time around.
#### #1: Codeforces rounds timing
Did you know that t...
gives up on his alternate competition formats. But in this post, I want to
focus on thenew patterns, never gives up on his alternate competition formats. But in this post, I want
to focus on thenew
46.
Group tutoring Hi. I offer classes for groups of 2-3 students.
I teach competitive programming with a focus on problem-solving.
There won't be many lectures because I can send you an article/video link instead.
The lesson cycle is usually: I choose a problem, you say your thoughts and ideas, I comment on incorrect ideas, and we talk about the valid solution(s), possibly with drawings and pseudocode.
In beginner groups, I might ask you to implement something, C++ or Python preferred.
There's a lot of homework and you're expected to practice a few hours per week.
We might spend half a lesson talking about 1-2 homework problems from last week.
This is intended.
We use Google Meet, shared whiteboard, and a collaborative editor Codebunk.
After a lesson, you get a video recording and a codebunk with code/text history like this one https://codebunk.com/pb/3501100331621/.
This allows you to copy links and code easily.
There's a Discord group chat to ask questions between classes.
- 1.5h les...
authored 300+ competition problems (Codeforces, Codechef, Hackerrank,
Topcoder, and interview problems, full time (it was part-time before that). I authored 300+ competition problems
(Codeforces, Codechef
47.
Live online mirror of The 2024 ICPC Asia Pacific Championship Hi,
We would like to invite you to participate in the [live online mirror contest of The 2024 ICPC Asia Pacific Championship](https://codeforces.com/contests/1938) next weekend.
ICPC Asia Pacific Championship is a new playoff round introduced to the Asia Pacific region this year. It is the contest for top non-winning teams from all regional contests in the region to qualify to the World Finals. See the [region rules](https://icpc.iisf.or.jp/asia-pacific/top/2023-24-cycle/) and [competition page](https://icpc.asia/) for more details.
The official contest is scheduled to start at [Saturday, 2 March 2024, 9am (UTC+7)](https://www.timeanddate.com/worldclock/fixedtime.html?msg=The+2024+ICPC+Asia+Pacific+Championship&iso=20240302T09&p1=95&ah=5). The live online mirror contest is scheduled to start [**only 5 minutes later**](https://www.timeanddate.com/worldclock/fixedtime.html?msg=The+2024+ICPC+Asia+Pacific+Championship+-+Online+Mirror&iso=20240302T0905&p1=95&ah=5), to keep both conte...
Championship is a new playoff round introduced to the Asia Pacific region this
year. It is the
48.
Thank You! :) Hey Everyone,
Hope everyone is keeping safe. I just wanted to drop in a quick announcement and some thank you notes!
I would be [leaving Topcoder](https://discussions.topcoder.com/discussion/11929/some-bittersweet-news-about-hmehta-me) next week and going forward all Topcoder announcements will be made from the [user:Topcoder_Updates,2021-10-07] account. Feel free to drop a message to Topcoder Updates or email at [email protected] if you have any questions related to Topcoder Competitions.
And most importantly Thank You!
Thank you to each one of you who competed and made this community a living example of a great community. I was very lucky to have driven a part of it at Topcoder Competitions.
I am and will always be a `competitive programming community` fan even though I don't compete anymore. Most of the friends I have made and the learnings I have had are because of this community. Meeting you all at various events, chatting with you all during the contests, seein...
49.
New feature of Polygon: tests for checkers and validators Good afternoon, Codeforces!
Today I'll tell you about a new feature of [Polygon](http://codecenter.sgu.ru/polygon/) system, which is used to prepare all Codeforces rounds. Of course the system is open to any user – many contests for other competitions and training camps are prepared there.
Two key elements of a problem, besides the author's solution, tests and statements, are two programs: the validator and the checker.
The validator is the program that reads the test and reports whether it corresponds to the condition of a problem or not. Validators must be absolutely formal – a validator validates a test if and only if it meets the conditions of the problem and can be safely added to the test set. You can easily write validators using the <a href="http://code.google.com/p/testlib">testlib.h</a> library. Sometimes authors neglect validators (which never happens during the Codeforces contests) and it threatens the validity of tests. Since the Codeforces contests contain hacks,...
New feature of Polygon: tests for checkers and validators, Good afternoon, Codeforces! Today I'll tell you about a new feature of
[Polygon](http, Today I'll tell you about a new feature of
[Polygon](http://codecenter.sgu.ru/polygon/) system
50.
California Informatics Competition (CALICO) Spring '24 
Hello Codeforces!
We are excited to invite you to compete in CALICO Spring '24! The contest starts [Saturday, April 27, 2024 at 4:00 p.m. PT](https://timeanddate.com/s/43cu) and will be 3 hours long. **Registrations are now open** and will be until April 24, 2023 at 11:59 p.m. PT, so [register here while you can](https://calico.cs.berkeley.edu/register/)! The contest will take place on our [custom judge platform](https://calicojudge.com/) and for the first time, contestants can compete **online or in-person at UC Berkeley**!
#### In-Person Contest (New!)
The CALICO team is proud to announce our **first in-person contest ever**—that's right, CALICO will be happening **LIVE** at UC Berkeley! We’ll be providing in-person contestants with exclusive merch, dinner, and opening/closing ceremonies with live guest speakers. This is also an excellent opportunity to explore the UC Berkeley campus, meet the team, a...
California Informatics Competition (CALICO) Spring '24, everyone, regardless if you’re totally new or an experienced competitor., opportunity to explore the UC Berkeley campus, meet the team, and make new
programming friends! If you’re, #### In-Person Contest (New!)
51.
Valentine Algorithm cUp 2015 Are you in love with algorithms? If you are don't miss this round and be algorithm's valentine ;)
On the night before valentine's day ([exact time](http://www.timeanddate.com/worldclock/fixedtime.html?day=13&month=2&year=2015&hour=18&min=30&sec=0&p1=166)), Valentine Algorithm cUp 2015 is going to take place.
There will be 6 problems and 3 hours to solve them. All of them are written by me([user:PrinceOfPersia,2015-02-05]).
This competition is like surprise languages but too different. 3 days before the contest, I will publish tutorial of 5 new algorithm languages(not programming languages) with their compiler codes. Each language is going to be really simple to learn and have at most 6 or 7 commands (they're not like programming languages).
Your program should print the code written in the language the problem says and checker will run it (pay attention that inputs are encoded, don't try to read form input, j...
This competition is like surprise languages but too different. 3 days before
the contest, I will, ]). This competition is like surprise languages but too different. 3 days
before the contest, I will
Announcement of Valentine Algorithm Cup 2015
52.
Kotlin Heroes Episode 9 Returns! Greetings Codeforces!
<img src="/predownloaded/dc/3d/dc3d601ff391e638c1f2b20ec167083978099bbe.png" style="width:500px;float:right;margin:0 1em 1em 1em;"/>
We are thrilled to announce the **return of Kotlin Heroes**! As we resume this competition, we're eager both to welcome back some familiar names and meet new participants. Let's make Kotlin Heroes: Episode 9 an occasion to remember!
We would like to thank everyone who participated in the previous eight Kotlin Heroes competitions: [Episode 1](https://codeforces.com/contests/1170,1171), [Episode 2](https://codeforces.com/contests/1211,1212), [Episode 3](https://codeforces.com/contests/1297,1298), [Episode 4](https://codeforces.com/contests/1346,1347), [Episode 5: ICPC Round](https://codeforces.com/contests/1432,1431), [Episode 6](https://codeforces.com/contests/1488,1489), [Episode 7](https://codeforces.com/contests/1533,1532), and [Episode 8](https://codeforces.com/contests/1571,1570).
Kotlin Heroes is a great way to play ...
**return of Kotlin Heroes**! As we resume this competition, we're eager both
to welcome back some familiar, We are thrilled to announce the **return of Kotlin Heroes**! As we resume this
competition, we're
Announcement of Kotlin Heroes: Episode 9 (Unrated, T-Shirts + Prizes!)
53.
Code Festival 2016: New Onsite Contest with Free Trip for Finalists! We announce a new international onsite competition: Code Festival 2016. The contests will be held on [AtCoder](http://atcoder.jp).
The top 20 foreign (non-Japanese) university students are invited to the Finals in Japan.
(Even if you are not a student, you can participate in qualification rounds and parallel rounds of onsite contests. All of these contests are rated.)
The flight tickets and hotels for finalists are paid by organizers.
There will be three qualification rounds.
Top 10 foreign students from round A and top 5 each from round B and C will qualify for the onsite contest.
- [Round A: September 24th, 21:00 JST](http://www.timeanddate.com/worldclock/fixedtime.html?iso=20160924T2100&p1=248).
- [Round B: October 10th, 13:00 JST](http://www.timeanddate.com/worldclock/fixedtime.html?iso=20161010T1300&p1=248).
- [Round C: October 23rd, 21:00 JST](http://www.timeanddate.com/worldclock/fixedtime.html?iso=20161023T2100&p1=248).
- Onsite Round: November 26th-28th
Als...
Code Festival 2016: New Onsite Contest with Free Trip for Finalists!, Also, there will be many interesting events during the onsite competition., We announce a new international onsite competition: Code Festival 2016. The
contests will be held
54.
Teams Qualified for Africa and Arab Collegiate Programming Championship — ACPC 2023 (+teens) Hello, Codeforces community!
I would like to congratulate all the teams that have qualified for ACPC2023.
I'm thrilled to meet and compete with all of you in this year's competition.
Since we're approximately a month away from the event, I believe it's a good idea to get to know the participating teams and assess their current levels. It's also a great idea to add them as friends to compete against them virtually in gyms.
If you qualified for this year's competition Please comment the following information and I'll update the blog as soon as possible. ( I will make a separate table for teens)
- Country
- University(!teens)
- Team name
- Team handles(separated by spaces)
I will add the team rating about a week before the competition as there might be some new grandmasters by then :)
Finally, "Welcome to ACPC"
And good luck to all the teams!
ACPC Teams
------------------
| **#** | **Country** | **University** | **Team name** | **...
I will add the team rating about a week before the competition as there might
be somenew
55.
Testlib: tests + CI Hello, Codeforces.
I have wanted for a long time and now, finally, I sat down and did it.
Many of you are familiar with my [Testlib](https://github.com/MikeMirzayanov/testlib) project. This is a library that helps you develop problems if you are using C++.
In the case of problems for Codeforces rounds, its use is mandatory. It seems to me that it is almost a de facto standard for preparing materials for completely different olympiads and competitions.
The history of С++-Testlib is almost lost in centuries, I published the first version in 2005.
Nowadays, making edits to Testlib has become tricky. The code grown to thousands of lines, also it has too long a history.
This increases the likelihood of accidentally changing some aspect of behavior, which will jeopardize the holding of a Codeforces round or another important competition.
In short, making a bug in this code or changing behavior anywhere is highly discouraged.
So I recently took the plunge and wrote some test...
holding of a Codeforces round or another important competition. In short,
making a bug in this code or
56.
Happy New Year! **Hello guys!**
**The new year is coming to an end, so I wish everyone a happy New year!**
This post is the [conclusion](http://codeforces.com/blog/entry/108044) of this mini-competition, just summing up the results :). In the last post, I couldn't mention everyone who left their comments, but I hope I didn't forget about anyone in this one! From below you can see how your rank has changed since the beginning of this mini-competition(Left one — Old, Right one — New), I hope that almost everyone has been able to achieve their goals, and those who have not achieved them will have another wonderful year for this!
### **Happy New Year Codeforces!**
### International grandmaster!
[user:Vercingetorix,2022-10-17] • [user:Vercingetorix,2023-01-01]!
### Grandmasters!
[user:jjang36524,2022-10-17] • [user:jjang36524,2023-01-01]!
[user:SecondThread,2022-10-17] • [user:SecondThread,2023-01-01]!
[user:anpoli99,2022-10-17] • [user...
Happy New Year!, changed since the beginning of this mini-competition(Left one — Old, Right one
—New), I hope
57.
IOI 2021 will be held online **TL;DR:** IOI 2021 was planned to held on-site with strong safety measures. Today, IC announced to turn it into an on-line contest (I guess due to travel difficulties). The IC is exploring the possibility of an optional on-site contest.
https://www.facebook.com/ioinformatics.org/posts/458218468862628
Dear Friends of IOI,
I hope you are doing well as COVID-19 is still rampaging all over the world. But as vaccines are becoming available, I hope we can all soon get back to our normal life before the pandemic.
The IC held the Winter meeting in late February. We have the following important information regarding IOI 2021 to share with the community.
First, IOI 2021, organized by Singapore, will still be an online competition much like the previous year. The competition week will fall between mid to late June.
Second, competition aside, in an effort to bring back some normalcy, IOI business will be conducted as usual. This includes collection of registration fees an...
, organized by Singapore, will still be an online competition much like the
previous year. Thecompetition, Second, competition aside, in an effort to bring back some normalcy, IOI
business will be conducted
58.
Codeforces: Domains For Groups Hello!
Are you missing something new? I have something to please you.
Regularly I host some events — Olympiads, onsites, and eventually, examinations and tests for students. On the one hand, Codeforces already offers a unique functionality — groups, the integration with Polygon, the possibility of choosing tasks from the archive and so on. But it doesn’t enough!
### Domains for groups
Here is an example of such a group. It is open for all — join it and look: http://example.contest.codeforces.com
##### Domain
Now when you are editing a group, you can specify its subdomain (from 3 to 20 alphanumeric characters, starts with a letter). When you specify the domain, the group will be accessible by a link http://yourgroupdomain.contest.codeforces.com. According to this link, the following is correct:
* Nothing extra will be displayed — the site contains only the information about competitions and blogs of your group and nothing else.
* A...
Hello! Are you missing something new? I have something to please you. Regularly
I host some
59.
Educational Codeforces Round 5 Hi, Codeforces!
Happy New Year! Holidays and 2015 year have passed and year 2016 is ahead. I wish you good luck in programming competitions and achieving all of your goals this year.
<img src="http://www.keviniriarte.com/wp-content/uploads/2014/04/new_season.jpg" style="max-width:100%; max-height:100%"/>
Educational Codeforces Round 5 will take place on [11 January 2016 at 18:00 MSK](http://www.timeanddate.com/worldclock/fixedtime.html?msg=Educational+Codeforces+Round+5&iso=20160111T1500) for the first and second divisions. You can read about educational rounds [here](http://codeforces.com/blog/entry/21496) and [here](http://codeforces.com/blog/entry/21565).
\<A year has passed, but paragraph remains unchanged.\>
The round will be unrated for all users and it will be held with extented ACM ICPC rules. You will have two hours to solve six problems. After that you will have one day to hack any solution you want. You will have access to copy any solution and test it locally...
Happy New Year! Holidays and 2015 year have passed and year 2016 is ahead. I
wish you good luck in, Hi, Codeforces! Happy New Year! Holidays and 2015 year have passed and year
2016 is ahead. I
Announcement of Educational Codeforces Round 5
60.
Sums and Expected Value — part 1 part 2: https://codeforces.com/blog/entry/62792
Watch my lecture-stream tomorrow (Thursday) at [14:00 CEST](https://www.timeanddate.com/worldclock/fixedtime.html?msg=EV+lecture+1&iso=20181025T14&p1=262) — <s>[https://www.youtube.com/watch?v=qdlPY37MBPo](https://www.youtube.com/watch?v=qdlPY37MBPo)</s> [https://www.youtube.com/watch?v=U_h3IjreRek](https://www.youtube.com/watch?v=U_h3IjreRek).
I will go through theory and problems from this blog.
The only prerequisite is knowing what is probability.
The next (harder) part on Monday.
The video will be available later, with timestamps for each problem — so you don't have to watch everything.
### Definition of EV
Let's say we bought a lottery ticket for 2$.
We will win 10$ with probability 10%, and 20$ with p-bility 2%.
On average, it gives us $0.1 \cdot 10 + 0.02 \cdot 20 = 1.4$,
so we are worse off after buying the ticket.
The computed average is called the expected value.
The expected value (EV, expecta...
$-th with prize $a_i$. You're quite good and you will win each competition with
p-bility 50%. Find
61.
Teams going to ICPC WF 2022 (Egypt 2023) — WIP List Hi there!
While we're waiting for the formal invitations to the ICPC World Final 2023, let's start the new post for the incoming competition, keeping the same idea of the [previous blog](https://codeforces.com/blog/entry/102593)
As many of you already know, next WF will be something like a two-in-one competition, without knowing the actual format yet.
I think it would be good to make two differents post, one per WF, because otherwise it would probably be a _very long_ post.
Anyway, let the people decide :)
_(I don't know if this poll works)_
Two posts:
The same post:
At least for now, we'll fill this post with teams of **THE FIRST WF** in Egypt, assuming that those are the qualified from Regionals **2021/2022**.
(Trying to be more specific: the teams that qualified in the Regional held after the one that qualified to Dhaka)
Please add a comment with your team information and I will add it to the post.
Info preferre...
While we're waiting for the formal invitations to the ICPC World Final 2023,
let's start thenew
62.
For contest writers: proposal tracking system <i>In 2021, some details (including requirements for problem writers) were changed. Read <a href="https://codeforces.com/blog/entry/85259">the link</a> for details.</i>
Hello, Codeforces!
New year brings changes to the Codeforces team. <a href="/blog/entry/49466">As you probably know</a> [user:GlebsHP,2017-01-04] completed his work as the chief coordinator of Codeforces. Gleb, thanks a lot! You did an excellent job and coordinated a lot of interesting rounds. You're a professional, an interesting person, you have impeccable taste to problems, and you proved to be brilliant and talented writer. Thank you that you were with us!
Hope to see your tasks on Codeforces many times again!
Nikolay [user:KAN,2017-01-04] Kalinin came to Gleb's place. He is also an experienced participant, Nikolay has already held several rounds as a coordinator. [user:KAN,2017-01-04] seriously engaged in programming contests since he was 12 years old. His major achievements: he won twice All-Russian Scho...
="https://codeforces.com/blog/entry/85259">the link for details. Hello,
Codeforces!New
63.
LGMSniper.com: See which LGMs you have beaten! LGM Sniper
==================
I just created a cool CF tool called [LGM Sniper](https://wumbogames.com/CompetitiveProgramming/LGMSniper). It looks at scoreboard data from every Div1 and Div1+Div2 round ever and tells you which LGM's you have beaten, how many times you have beaten them, and which rounds you beat them in. You can also compare yourself to your friends to see which one of you wins more! If you want to compare yourself with some friends, check the 'show ex-lgms' box and enter the friend you want to compare to as Handle #2, and they will show up on the bottom.
You can try it out for yourself at [lgmsniper.com](https://wumbogames.com/CompetitiveProgramming/LGMSniper), or in the competative programming section of [Wumbo Games](https://wumbogames.com/), if you would prefer. Tooltips show the name of the rounds you won in (hover your mouse over the checkmark).
If you find any interesting facts or have suggestions for how I could improve the tool, let me know in the co...
LGM and you'll annoy me.
Update: New Features ------------------ I added a couple new
64.
AI Cup 2020 Hello everyone!
[AI Cup 2020](https://russianaicup.ru/) — the annual artificial intelligence programming championship by Mail.Ru Group is already running.
AI Cup — open artificial intelligence programming contest. Test yourself writing a game strategy! It’s simple, clear and fun!
This year's theme is — RTS. We are waiting for you on [our site](https://russianaicup.ru/)! The site is already open, you can start implementing your strategies.
Ninth AI Cup championship is named CodeCraft. You are to program an artificial intelligence to control a number of units, gather resources, build your settlement and attack your enemies. Your strategies will compete with each other in the Sandbox and the championship. Currently availiable programming languages: C++, C#, F#, D, Go, Java, Kotlin, Scala, Python, Rust. The Sandbox is already open. Good luck!
## Schedule
- Sandbox: already open for everyone.
-...
were powerless and not ready. In this regard, we thought to cancel the merch
in thiscompetition, In this regard, we thought to cancel the merch in this competition, but a the
community did not
65.
Google Code Jam 2019 Qualification Round Google Code Jam 2019 Qualification Round will start on [April 5 at 23:00 UTC](https://www.timeanddate.com/worldclock/fixedtime.html?msg=Google+Code+Jam+2019+Qualification+Round&iso=20190405T23&p1=1440) and last for 27 hours. Here is the [official announcement](https://groups.google.com/d/msg/google-code/OEGCnQPevB4/soNr91gbBAAJ):
> Hi everyone,
>
> Code Jam is back for its 16th year, kicking off with the Qualification
> Round in one week! We're excited to provide you with another season of
> intriguing problems (including some interactive ones) and a refreshed user
> experience. **[Register today](https://codingcompetitions.withgoogle.com/codejam/)**
> for a chance to earn the coveted title of Code Jam Champion at the World
> Finals in San Francisco, California, and take home the grand prize of
> $15,000.
>
> Here’s what you need to know about this year’s competition:
>
> * The 27-hour Online Qualification Round begins on **Friday, April 5 @
> 23:00 UTC**; registrati...
must attain a final score of > at least 30 points to move on to Code Jam’s
Round 1. If you're anew, year, Code Jam has a [new competition
interface](https://codingcompetitions.withgoogle.com/). To, . > > Here’s what you need to know about this year’s competition: > > * The
27-hour Online, This year, Code Jam has a [new competition
interface](https://codingcompetitions.withgoogle.com
66.
California Informatics Competition (CALICO) Spring '23 Hello Codeforces!
We are excited to invite you to compete in the California Informatics Competition (CALICO) Spring '23! The contest will take place on [Saturday, April 8, 2023 from 4:00 p.m. to 6:30 p.m. Pacific Time](https://timeanddate.com/s/430d). **Registrations are now open** and will be until Thursday, April 6, 2023 at 11:59 p.m. Pacific Time, so [register here while you can](https://calico.cs.berkeley.edu/register)! The contest will take place virtually on our [custom judge platform](https://calicojudge.com/).
The California Informatics Competition (CALICO) is a semiannual team programming contest organized by students at the University of California, Berkeley. We create original problems to encourage students to grow their problem-solving skills and learn algorithms in fun and exciting ways. Check out our [website](https://calico.cs.berkeley.edu/) to learn more about the contest and join our [discord server](https://discord.gg/RTdxtzXQZ5) to get announcements, make teams...
California Informatics Competition (CALICO) Spring '23, everyone, regardless if you’re totally new or an experienced competitor., Competition (CALICO) Spring '23! The contest will take place on [Saturday,
April 8, 2023 from 4:00 p.m. to 6
67.
Who wanna take apart in friendly competition? **Hello Guys!**
I think everyone who is on this site in one way or another likes to solve problems! So I would like to offer you a _little competition_ :)
All you need is just to:
1. **Write your goal** you would like to achieve before new year, current rating and the number of solved problems.
1. **Solve many different interesting tasks** and raise your rating in the rounds until the new year!
1. **In the new year**, I will write all the progress of each of the users who participate in a new post, and we can start the new year with new ideas!
(List will be updated)
Participants:
Legendary Grandmasters
[user:Vercingetorix,2022-10-17],
Grandmasters
[user:physics0523,2022-10-17], [user:jjang36524,2022-10-17], [user:dmga44,2022-10-17], [user:Artyom123,2022-10-17], [user:SecondThread,2022-10-17], [user:FairyWinx,2022-10-17],
International Masters
[user:anpoli99,2022-10-17],
Masters
[user:swift-zym,2022-10-17], [user:jucason_xu,202...
Who wanna take apart in friendly competition?, . **Write your goal** you would like to achieve before new year, current rating
and the number of solved, 1. **In the new year**, I will write all the progress of each of the users who
participate in a, 1. **Solve many different interesting tasks** and raise your rating in the
rounds until thenew, 1. **Write your goal** you would like to achieve before new year, current
rating and the number of
68.
Designing a new competition format Don't you think that most of the current programming competitions are boring and monotonous? Can you think of something that could be more entertaining, especially for the viewers?
Let's brainstorm together. You can do whatever you want! How about extremely long 24-hour rounds? 5v5 match-ups with 10 computers? Or maybe a timer that starts at 1 hour at the beginning of the competition and goes up only if you solve a problem, so you literally fight only against the clock and see your rivals being eliminated? Alternatively, is there something from the existing competitions that you really enjoy and don't want to lose?
Designing a new competition format, with 10 computers? Or maybe a timer that starts at 1 hour at the beginning of
thecompetition and goes, competition and goes up only if you solve a problem, so you literally fight
only against the clock and
69.
Educational Codeforces Round 21 + announcement of 2nd Hello Barcelona ACM-ICPC Bootcamp Hello Codeforces!
On [May 15, 18:05 MSK](https://www.timeanddate.com/worldclock/fixedtime.html?day=15&month=5&year=2017&hour=18&min=5&sec=0&p1=166) will be held Educational Codeforces Round 21.
Series of Educational Rounds continue being held as Harbour.Space university initiative! You can read the details about the cooperation between Harbour.Space and Codeforces in the <a href="http://codeforces.com/blog/entry/51208">blog post</a>.
The round will be **unrated** for all users and will be held on extented ACM ICPC rules. After the end of the contest you will have one day to hack any solution you want. You will have access to copy any solution and test it locally.
You will be given **7 problems** and **2 hours 30 minutes** to solve them. We hope that everyone will find something interesting in this contest.
The round was prepared by Mikhail [user:PikMike,2017-05-14] Piklyaev, Mikhail [user:MikeMirzayanov,2017-04-14] Mirzayanov and me.
Here is message from Igor Maksimo...
an appropriate introduction for teams and students new to the world of ACM
ICPC and competitive, students new to the world of ACM ICPC and competitive programming competitions
in general. The Division B
70.
Russian AI Cup 2017 — CodeWars Hey everyone!
Good news — Russian AI Cup 2017 has started! This competition is being held for the sixth time, and this time, hopefully, we will make happy all the fans of the RTS game genre — you will be controlling 500 vehicles of 5 different types at once. The task is to destroy the opponent!
Try yourself in creating an artificial intelligence, it's simple and fun. Go to [Russian AI Cup site](http://russianaicup.ru) and enter the battle. Good luck!
[cut]
### What is it?
**Russian AI Cup** — largest annual artificial intelligence programming contest in Russia, and third open competition for talented IT-specialists that is part of Mail.Ru Group strategy of forming and developing competitive Russian IT-industry on a global scale.
Following programming languages are supported: C++, C#, Java, Pascal, Python 2, Python 3 и Ruby. Anyway, as previously, we are ...
Good news — Russian AI Cup 2017 has started! This competition is being held for
the sixth, Hey everyone! Good news — Russian AI Cup 2017 has started! This competition is
being held
71.
ACM-ICPC World Finals 2017 <center>
<img src="/predownloaded/4d/47/4d475972ef3e14948e881152064cc208a4f83540.png"/>
</center>
ACM-ICPC World Finals 2017 will begin on <a href="https://www.timeanddate.com/worldclock/fixedtime.html?msg=ACM+ICPC+2017+World+Finals&iso=20170524T09&p1=1920&ah=5">May 24, 2017 at 15:00 (UTC)</a>.
This event is the main event of the year in the world of sports programming!
This year ICPC Regional
participation included 46,381 of the finest students and faculty in computing disciplines from 2,948 universities in 103
countries on six continents. A record 50,145 students and 5,073 coaches competed in ICPC and ICPC-assisted
competitions this year, setting new records in participation.
Codeforces wishes the teams to show a vivid and interesting contest contest. We wish to find beautiful solutions, write without bugs and enjoy many accepted problems!
Links:
* <a style="font-weight: bold;" href="http://static.kattis.com/icpc/wf2017/">Current results</a>
* <a href="https:/...
coaches competed in ICPC and ICPC-assisted competitions this year, setting new
records in participation, students and 5,073 coaches competed in ICPC and ICPC-assisted competitions
this year, settingnew records
72.
Calling CF Community to Support Rescheduling ACPC **UPD: it's now rescheduled! thank you all for the support.**
Hello Codeforces,
I didn't want to publish this blog during these circumstances, as it's the last thing to care about, but I'm publishing it hopefully ACPC organizers see it.
Last Saturday, we got an email saying that the ICPC world finals, which were supposed to be in 11 days in Sharm El-Sheikh, got rescheduled to a later time. And it was expected that the ACPC, which is supposed to be in 17 days in the same hotel, would get rescheduled too. but apparently the competition is still on its previously scheduled date!! I would like to note that ACPC is scheduled to be in the same hotel as ICPC.
Let's talk about it from many perspectives.
From the travel perspective, sadly while talking I will partition Palestine into the West Bank and Gaza, but we're one nation and stand together with each other.
Firstly, two teams from Gaza are supposed to participate in ACPC this year, and surely, they will not be able to co...
get rescheduled too. but apparently the competition is still on its previously
scheduled date!! I, think that there's a contestant will be ready mentally to participate in a
competition right now, and
73.
California Informatics Competition (CALICO) Fall '23 Hello Codeforces!
We are excited to invite you to compete in the California Informatics Competition (CALICO) Fall '23! The contest will start on [Saturday, November 18, 2023 at 4:00 p.m. PT](https://timeanddate.com/s/435k) and will be 3 hours long. **Registrations are now open** and will be until November 15, 2023 at 11:59 p.m. PT, so [register here while you can](https://calico.cs.berkeley.edu/register/)! The contest will take place virtually on our [custom judge platform](https://calicojudge.com/).
The California Informatics Competition (CALICO) is a semiannual team programming contest organized by students at the University of California, Berkeley. We create original problems to encourage students to grow their problem-solving skills and learn algorithms in fun and exciting ways. Check out our [website](https://calico.cs.berkeley.edu/) to learn more about the contest and join our [discord server](https://discord.gg/RTdxtzXQZ5) to get announcements, make teams, hang out, and mo...
California Informatics Competition (CALICO) Fall '23, everyone, regardless if you’re totally new or an experienced competitor., Competition (CALICO) Fall '23! The contest will start on [Saturday, November
18, 2023 at 4:00 p.m. PT](https
74.
Announcement: 2nd Hello Barcelona programming bootcamp in collaboration with Moscow Workshops ACM ICPC Hello, Codeforces!
I am pleased to announce [the 2nd Hello Barcelona Programming Bootcamp in collaboration with Moscow Workshops ACM ICPC](http://in.harbour.space/icpc/acm-icpc-hello-barcelona-bootcamp-autumn-2017/), which will be hosted by our partner [Harbour.Space University](https://harbour.space/) together with [Moscow Workshops ACM ICPC](https://it-edu.mipt.ru/en/), [ITMO University](http://en.ifmo.ru/en/), [Moscow Physics and Technology University](https://mipt.ru/en/), [Saint Petersburg State University](http://english.spbu.ru/) and Codeforces!
<br/>
<center>
<a href="http://in.harbour.space/icpc/acm-icpc-hello-barcelona-bootcamp-autumn-2017/"><img src="http://d9hhrg4mnvzow.cloudfront.net/in.harbour.space/icpc/acm-icpc-hello-barcelona-bootcamp-autumn-2017/5a56f9db-logo-acm-icpc-12_0d70280d701x000005.png"/></a>
</center>
<br/>
The boot camp will be held from September 27th to October 5th in Barcelona. This time it will be at the beautiful and technologically mind-be...
Regionals and international competitions. This is an appropriate introduction
for teams and studentsnew, international competitions. This is an appropriate introduction for teams and
studentsnew to the world of
75.
HFT Battle 2017 ### Hello Codeforces!
[HFT Battle 2017](http://hftbattle.com) is going on – the trading algorithms competition, in which every participant can try on an HFT researcher’s hat. The goal is to create a stable and profitable HFT algorithm by researching a market microstructure and a behaviour of the financial instrument. In May we will be hosting another 24-hour competition in code optimization and speeding up based on algorithms created during HFT Battle. We hope that Codeforces users will especially like this format :)
During the competition we provide you a set of real HFT-instruments for research and strategy analysis and real market data from one of the world’s largest exchanges. Same as last year, trading conditions are simplified compared to the real ones: there are lower fees and [round-trip](https://docs.hftbattle.com/en/HFAQ.html#simulator).
Also there are some significant differences from the previous competition:
- You are able to create your strategies both in C++ ...
algorithms competition, in which every participant can try on an HFT
researcher’s hat. The goal is to create, The competition ends on the 30th of April 2017. The final testing will be held
after that on a set
76.
Best of COCI #1 Since a new season of COCI (Croatian Open Competition in Informatics) started [last saturday](https://codeforces.com/blog/entry/96022), here is the first in a series of COCI appreciation posts (I will post one after each COCI round, so six in total!). For my coaching, I went through all COCI contests since 2006 to gather tasks and selected some of my favorite ones.
### Notes
- I skipped a lot of the really hard tasks because they weren't useful for my students. I kept a list of these tasks, if someone wants it, they can PM me. Also, I only considered COCI, not COI. This current season is not being considered.
- There are many great tasks outside of the 48 shown (throughout the series), so it's worth it to go through other tasks as well. I have selected just my favorite ones.
- These tasks are maybe not always the most innovative, I have selected the tasks that are most useful for coaching and learning new ideas, so for people who already know the idea, the difficulty might be mu...
Since a new season of COCI (Croatian Open Competition in Informatics) started
[last saturday](https
77.
Invitation to new OI style contest Info(1) Cup Hello everyone!
I'm writing this entry to invite you all to take part in [the first edition of Info (1) Cup contest](http://info1cup.com/). It is an individual contest with algorithmic tasks and we will accept only C++ sources. The contest itself has 2 parts, both of which held online.
**You can still take part in the online mirror in any frame of 5 hours before [time](https://www.timeanddate.com/countdown/generic?iso=20170412T15&p0=5121&msg=infO%281%29+Cup+International+Round+-+Online+Mirror+END&font=cursive&csz=1). We invite you all to participate. The tasks should be challenging for everyone
The [live scoreboard](http://open.info1cup.com:8890/Ranking.html) of the online mirror is on.**
PS: As in all the other contests that have online mirrors, I kindly ask you not to discuss the tasks until all the rounds and their online mirrors end. After that, on the official site, you'll find the editorials of the problems.
The first one consists of a national contest in which only ...
Invitation to new OI style contest Info(1) Cup, happy to receive any kind of feedback regarding the competition so that we can
improve it the next, . However, we'd be happy to receive any kind of feedback regarding the
competition so that we can
78.
Yandex.Algorithm 2016 Finals **UPD2**: Tomorrow (July 31st, Sunday) at UTC 10:00 there will be an online mirror of Yandex.Algorithm final round.
**[Enter contest](https://contest.yandex.com/contest/2623/enter/)**.
Everybody are invited to participate! You may discuss problems in comments after the contest ends.
**UPD3**: The online mirror has finished! Congratulations to ImBarD aka [user:Vercingetorix,2016-07-31] for taking the first place.
**[Problem editorial](https://yadi.sk/d/u7eFSFHqtoMPe)**
===================================================
Hi everybody!
We're glad to remind you that tomorrow, [July 29th, at 9:00 AM UTC](http://www.timeanddate.com/worldclock/fixedtime.html?year=2016&month=7&day=29&hour=12&min=0&sec=0&p1=166) there will be the Final Round of Yandex.Algorithm 2016 in Minsk. List of finalists and elimination stage results are available on Yandex.Algorithm [website](https://contest.yandex.ru/algorithm2016/results/).
<br /><br />
<center>
<img src="https://s31.postim...
) there will be a mirror of the competition. Everybody can participate in it,
solve the same problems, =2016&month=7&day=31&hour=13&min=0&sec=0&p1=166) there will be a mirror of the
competition. Everybody
79.
Codeforces Round #495 (Div. 2) Hi everybody!
Summer... It is a wonderful time for traveling, walking with friends, new discoveries and, of course, writing new exciting contests at Codeforces. Thus, I bring to your attention my new Codeforces Round #495 (Div. 2) with interesting tasks that will take place on [contest_time:1004]. If your rating is less than 2100, this round will be rated for you; otherwise, you can participate out of competition.
I would like to thank Mike [user:MikeMirzayanov,2018-07-04] Mirzayanov for his help with problems preparing and for Codeforces and Polygon platforms. Also, Ildar [user:300iq,2018-07-04] Gainullin, Dmitry [user:_kun_,2018-07-04] Sayutin, Daniil [user:danya.smelskiy,2018-07-04] Smelskiy, Chin-Chia [user:eddy1021,2018-07-05] Hsu, and Kevin [user:ksun48,2018-07-05] Sun for the problems testing.
You will be given 6 problems and 2 hours to solve them. Scoring distribution will be announced later.
In this round, you will have to help Sonya with her daily problems. Good ...
Hi everybody! Summer... It is a wonderful time for traveling, walking with
friends,new, Summer... It is a wonderful time for traveling, walking with friends, new
discoveries and, of
Announcement of Codeforces Round 495 (Div. 2)
80.
Panic relief pre-OI (and similar competition) ... There are only about 10 days left before I choke myself to death at Vietnamese OI this year.... At the moment, a part of me is really relaxed, because this year outcome won't affect my future a lot, but the other part of me is being stressful and annoying as hell, because throughout the year of 2018, I learned a lot, and obviously I cannot have the same (or even worse) than last year, right. That part of me keep pondering upon a question for the last 30 days: **"What the f--- should I do to prepare for this?"**[cut].
_(Stressed out. Literally.)_
Now, I'm not a type of competitor that work my ass off every hour in every day, aiming for IOI and stuffs. Instead, I tend to spend my time on practicing less than my friends _(and more on some unrelated cause ==)_. That's one of the reason why my knowledge and skill are somewhat inadequate comparing to some other competitors in...
Panic relief pre-OI (and similar competition) ..., me discover something new to help me fill in my time, with not much left until
VOI., when we are very close to the competition. Don't try to learn and apply new
things or fill a hole, Firstly: quality >>>>> quantity, especially when we are very close to the
competition. Don't try to
81.
California Informatics Competition (CALICO) Fall '23 Hello Codeforces!
We are excited to invite you to compete in the California Informatics Competition (CALICO) Fall '23! The contest will start on [Saturday, November 18, 2023 at 4:00 p.m. PT](https://timeanddate.com/s/435k) and will be 3 hours long. **Registrations are now open** and will be until November 15, 2023 at 11:59 p.m. PT, so [register here while you can](https://calico.cs.berkeley.edu/register/)! The contest will take place virtually on our [custom judge platform](https://calicojudge.com/).
The California Informatics Competition (CALICO) is a semiannual team programming contest organized by students at the University of California, Berkeley. We create original problems to encourage students to grow their problem-solving skills and learn algorithms in fun and exciting ways. Check out our [website](https://calico.cs.berkeley.edu/) to learn more about the contest and join our [discord server](https://discord.gg/RTdxtzXQZ5) to get announcements, make teams, hang out, and mo...
California Informatics Competition (CALICO) Fall '23, everyone, regardless if you’re totally new or an experienced competitor., Competition (CALICO) Fall '23! The contest will start on [Saturday, November
18, 2023 at 4:00 p.m. PT](https
82.
California Informatics Competition (CALICO) Fall '22 Hello Codeforces!
We are excited to invite you to compete in the California Informatics Competition (CALICO Fall ‘22)! The contest will take place on [Saturday, November 26, 2022 from 4:00 p.m. to 7:00 p.m. Pacific Time](https://www.timeanddate.com/worldclock/fixedtime.html?msg=CALICO+Fall+%2722+Online&iso=20221126T16&p1=791). **Registrations are now open** and will be until Wednesday, November 23, 2022 at 11:59 p.m. Pacific Time, so [register here while you can](https://forms.gle/WdN5RGoHTP4g4Gjz8)! The contest will take place virtually on our [custom judge platform](https://calicojudge.com/).
The California Informatics Competition (CALICO) is a semiannual team programming contest organized by students at the University of California, Berkeley. We create original problems to encourage students to grow their problem-solving skills and learn algorithms in fun and exciting ways. Check out our [website](https://calico.berkeley.edu/) to learn more about the contest and join our [disc...
California Informatics Competition (CALICO) Fall '22, everyone, regardless if you’re totally new or an experienced competitor., Competition (CALICO Fall ‘22)! The contest will take place on [Saturday,
November 26, 2022 from 4:00 p.m. to
83.
An awesome list for competitive programming! This is a project I started from late January 2016.
My motive is that: Although there's fantastic information out there, I think they're still spread all over the place. Therefore, in my opinion it would probably be cool if there's an [awesome list](https://github.com/sindresorhus/awesome) for competitive programming! ( *It's now featured on the main list!* )
I'm actively updating the list here: [https://github.com/lnishan/awesome-competitive-programming](https://github.com/lnishan/awesome-competitive-programming)
# Awesome Competitive Programming [](https://github.com/sindresorhus/awesome)
A curated list of awesome `Competitive Programming`, `Algorithm` and `Data Structure` resources.
Created with a view to connecting people to information, this list below contains a complete collection of all the fantastic resources I've collected over the course of my 11...
Free Documentation License). | | ★★☆ | [How to Solve It: A New Aspect of
Mathematical Method](https, programming competitions. The competition consists of unique programming
challenges which must be
84.
Companies interested in hiring a Competitive Programming background new grad? Hello everyone!
I'm reaching out to ask for your help in finding companies that are currently hiring new graduates with a competitive programming background. I recently received news from Google and Meta that they would not be able to extend me an offer due to business reasons, despite having interned at Meta and successfully completing the interview process with Google.
As a recent graduate, I am eager to start my professional career and continue learning and growing. However, given the current economic situation in the US and other countries, finding job openings and securing interviews has been a significant challenge. Additionally, finding sponsors for visas has been another hurdle to overcome.
I have experience working in big tech, having completed four internships at Meta, and I also have a strong background in competitive programming, including two ICPC WF and IOI competitions. I know that this type of profile can be attractive to companies, but I am unsure where to loo...
Companies interested in hiring a Competitive Programming background new grad?, hiring new graduates with a competitive programming background. I recently
received news from Google
85.
Google Kick Start 2021 Looking for a way to stay connected, try something new, and have a little fun? The [**Kick Start 2021**](https://codingcompetitions.withgoogle.com/kickstart?utm_medium=email&utm_source=toolkit%20template&utm_campaign=reg_promo&src=Online/TOPs/KS) season has begun!
**Kick Start** offers **programmers of all skill levels** the opportunity to **boost your skills** through a series of intriguing algorithmic and mathematical problems designed by Google engineers. **Each round starts fresh**, so give any one of our 2021 online rounds a try — or join them all!
**Join**
* Create a [Coding Competitions profile](https://codingcompetitions.withgoogle.com/profile) and then [register](https://codingcompetitions.withgoogle.com/kickstart/register?utm_medium=email&utm_source=toolkit%20template&utm_campaign=reg_promo&src=Online/TOPs/KS) for Kick Start.
* Check out [the full schedule](https://codingcompetitions.withgoogle.com/kickstart/schedule?utm_medium=email&utm_source=university_progr...
Looking for a way to stay connected, try something new, and have a little fun?
The [**Kick Start
86.
IOI 2018 impressions and conclusions Hi there!
As you all are aware, IOI 2018 is now over, and I felt the need to write a few lines about it, about my experience of it, and about my conclusions. I don't normally do that, but this was my last IOI and likely the end of my intense CP career.
So, the problems were absolutely great! Big up to the scientific committee. However, I'm sort of addicted to the codeblocks debugger which ruined the whole experience for me. As a matter of fact, the only reason for which codeblocks remained my primary editor was because its debugger was awesome and the only alternative of a better editor that I saw (better on the long run, including future real-life programming experience) would be vim which I knew is not even close to as friendly when it comes to user friendliness of debugging. I've also had competitions on a regular basis for 7 years and never had a time interval where I could say: well let's try something new cause we don't have anything useful to do (as I would always tell mys...
never had a time interval where I could say: well let's try something new
cause we don't have, opportunity, make from it something more than a random online competition with
higher stake. I was, say: well let's try something new cause we don't have anything useful to do
(as I would always tell
87.
Codeforces Round #536 (Div. 2) Hello, Codeforces!
It's my honor to invite you to Codeforces Round #536 (Div. 2), which takes place at [12:35 UTC, January 31st, 2019](https://www.timeanddate.com/worldclock/fixedtime.html?msg=Codeforces+Round+%23536+%28Div.+2%29&iso=20190131T1235&p1=1440&ah=2). The round will be **rated** for all division 2 participants **(with rating less than 2100)**. Also we warmly welcome those division 1 participants to join us out of competition.
This is my second round on Codeforces platform, and my first round was on January 31st, **2018**, which is such a coincidence that I would like to say thanks to [user:KAN,2019-01-29] for his awesome coordination and great dedication to this round. Besides, much thanks to testers [user:Aleks5d,2019-01-29], [user:cyand1317,2019-01-29], [user:mohammedehab2002,2019-01-29], [user:osaaateiasavtnl.,2019-01-29] for their excellent testing work. Also, I would like to appreciate the Codeforces platform created and maintained by [user:MikeMirzayanov,2019-01-...
participants to join us out of competition. This is my second round on
Codeforces platform, and
Announcement of Codeforces Round 536 (Div. 2)
88.
Yandex.Algorithm 2018 Hello everybody!
Yandex.Algorithm 2018 team is glad to announce that the registration for the seventh competitive programming (and even more) championship held by Yandex is [open](https://contest.yandex.com/algorithm2018/)! The championship is a wonderful opportunity to practice with interesting problems, compete against addicted programmers all over the world, and battle for a brand T-shirt. As usual, 25 most successful addicted competitive programmers will be invited to onsite finals that will be held in Saint Petersburg on May, 19.
In case you feel tired of classical competitive programming problems style, or just seek for competitions of any possible kind, you might be interested in new tracks we announce: optimization and ML.
Warm-up round will take place [this Sunday](https://www.timeanddate.com/worldclock/fixedtime.html?msg=Yandex.Algorithm+2018+Warm-up+round&iso=20180211T20&p1=166)!
**UPD**: [link](https://contest.yandex.com/algorithm2018/contest/7456/enter/) to wa...
competitions of any possible kind, you might be interested in new tracks we
announce: optimization and ML., in new tracks we announce: optimization and ML. Warm-up round will take place
[this Sunday
89.
My graduation project: Badminton Playing Robot Hello everyone,
I have been a permanent participant in competitive programming for many years now. I have been participating in ACM-ICPC for 3 years now, and managed to qualify for the world finals 2017.
Now that I have graduated from the department of Computer and Automation Engineering in Damascus University, I want to share with you my graduation project: badminton playing robot. In this project I used many algorithms that I learned from competitive programming (such as BFS, LIS and of course a lot of geometry).
We used LIS to filter noise data of shuttle detection and BFS,DFS to implement Indoor Location System for robot tracking and queries like sum of sub-rectangle in an array, and we didn't use any libraries for image processing.
I’m so glad that I managed to use the techniques I learned from competitive programming in my project. I'm also delighted that I was able to prove wrong those who say that competitive programming isn’t applicable in practical life, since I w...
**UPD:** My new robot for WRO competition: [WRO](https://youtu.be/akM8H4mN5KU)
90.
Educational Codeforces Round 42 (Rated for Div. 2) Hello Codeforces!
On [April 10, 14:35 UTC](https://www.timeanddate.com/worldclock/fixedtime.html?day=10&month=4&year=2018&hour=17&min=35&sec=0&p1=166) Educational Codeforces Round 42 will start.
Series of Educational Rounds continue being held as [Harbour.Space University](https://harbour.space/) initiative! You can read the details about the cooperation between [Harbour.Space University](https://harbour.space/) and Codeforces in the <a href="http://codeforces.com/blog/entry/51208">blog post</a>.
This round will be **rated for Div. 2**. It will be held on extented ACM ICPC rules. After the end of the contest you will have one day to hack any solution you want. You will have access to copy any solution and test it locally.
You will be given **7 problems** and **2 hours** to solve them.
The problems were prepared by me and Alex [user:fcspartakm,2018-04-09] Frolov.
We'd like to thank Nikolay [user:KAN,2018-04-09] Kalinin, Grigory [user:gritukan,2018-04-09] Reznikov,...
From the ever present in ACM World Finals city of Moscow, to the new-comer on
the world stage city
Announcement of Educational Codeforces Round 42 (Rated for Div. 2)
91.
World Finals: Live 15:24 — Closing ceremony will start shortly and you can watch it on ICPC Live. That's probably it for this translation. Bye-bye, see you soon
[cut]
15:10 — Moscow SU finished with 6
14:55 — I'll try to ask all top teams about number of problems they had solved right after the contest
14:51 — Tokyo trying to solve 2 almost simultaneously. Were they success?
14:48 — Seems like Gennady submitted B and very nervously walking in backgrounnd while Niyaz working on B. An by the wave of joy it seems they got it
14:28 — SPb SU get I quite likely. They are now seem to work on B
14:18 — Seems like SJTU got E right. Meanwhile ~tourist,2013-07-03 is seems to type B currently
14:08 — Based on their reaction Warsaw seems to have got something accepted. I probably would rather focus on video feeds of top teams, sorry for not fulfilling all photo requests
14:05 — Perm State University:
 - [ICPC Live](http://icpc2013.ru/
competition/live.xml) powered
92.
Codeforces: Results of 2020 [Annual Report] Hi Codeforces!
Yes, I know it's already April. Time flies so fast lately! Exactly a year ago we were just learning all the "delights" of lockdown.
So let's remember this 2020! What was it like? I don't know about you, but we had a hell of a lot of work.
I will now show you some graphs and you will be very surprised. Lockdown effect? Of course, but we did our best too.
Many thanks to everyone who did not stand aside! In 2020, we celebrated our 10th anniversary and crowdfunding money helps us grow and move forward. You helped us and each other. Thank you.
<a href="https://codeforces.com/10years/supporters">Thank you for your contribution!</a>
We've been working hard all year to make this community a better place. Did it work out? It's up to you to judge.
Many thanks to everyone who invested time and effort:
* [user:geranazavr555,2021-04-09], [user:kuviman,2021-04-09], [user:cannor147,2021-04-09] helped a lot with development and new features;
* [user:Una_Shem,2021-...
], [user:cannor147,2021-04-09] helped a lot with development and new features;
* [user:Una_Shem,2021
93.
ICPC Finals 2019 <img src="/predownloaded/02/25/02253adce36abb83bcaedca3cd1498b9d459d90d.png" style="margin: 0 0 0 1em; float: right;">
ICPC World Finals 2019 will begin on <a href="https://www.timeanddate.com/worldclock/fixedtime.html?msg=ICPC+World+Finals+2019&iso=20190404T12&p1=320&ah=5">April 4, 2019 at 11:00 (UTC)</a>.
This event is the main event of the year in the world of sports programming!
In the past 20 years alone, ICPC participation has increased by more than 2000%. The contest evolved into its present form as a multi-tier competition in 1977, with the first finals held in conjunction with the ACM Computer Science Conference. Last year, ICPC Regional
participation included 52,709 of the finest students and faculty in computing disciplines from 3,233 universities in 110 countries.
We remind you that in the current world champion is the team of Moscow State University.
Codeforces wishes the teams to show a vivid and interesting contest. We wish to find beautiful solutions, write ...
its present form as a multi-tier competition in 1977, with the first finals
held in conjunction with
94.
About DYNAMIC TECHNOLOGY LAB, Pte Ltd. <img src="/predownloaded/d0/25/d025e190ddafe382106a5faf70b723d41bd25dbf.png" align="right" style="height: 100px;" alt="DYNAMIC TECHNOLOGY LAB, PTE LTD LOGO"/>
### Hi Codeforces!
**We are [Dynamic Technology Lab, Pte Ltd. (DTL)](https://www.dytechlab.com)**, a _quantitative hedge fund_ engaging in global securities trading with multiple asset classes. Since our founding in 2009, from humble beginnings in a home garage, we are now a _sizable well-established financial institution_ with offices in **Singapore, Shanghai, Beijing, and Hanoi**. Our success is fueled by some of the most curious minds who are relentless in their _pursuit of innovation_.
As a **tech-focused Licensed Fund Management Company** under the Monetary Authority of Singapore, DTL is dedicated to producing _strong consistent returns_ for its investors by relying on mathematical and statistical models to drive its investment process.
## What is Quantitative Trading
<img src="/predownloaded/a8/89/a8891eb7ea5...
experts and you will be able to learn a lot from them, especially if you are
new to the industry, will be able to learn a lot from them, especially if you are new to the
industry!
95.
Russian AI Cup 2016 — CodeWizards Hey everyone!
Good news — Russian AI Cup 2016 has started! This competition is being held for the fifth time, and this time, hopefully, we will make happy all the fans of the MOBA game genre — you will be controlling a wizard, and together with 4 teammates you will try to destroy enemy base with magic and help of minions.
Try yourself in creating an artificial intelligence, it's simple and fun. Go to [Russian AI Cup site](http://russianaicup.ru) and enter the battle. Good luck!
### What is it?
**Russian AI Cup** — largest annual artificial intelligence programming contest in Russia, and third open competition for talented IT-specialists that is part of Mail.Ru Group strategy of forming and developing competitive Russian IT-industry on a global scale.
Following programming languages are supported: C++, C#, Java, Pascal, Python 2, Python 3 и Ruby. Anyway, as previously, we are ready to support language packages, realized by the community.
We welcome bo...
Good news — Russian AI Cup 2016 has started! This competition is being held for
the fifth, Hey everyone! Good news — Russian AI Cup 2016 has started! This competition is
being held
96.
Codeforces Round #829 (Div.1, Div.2, based on Moscow Team Olympiad, rated) Hi everybody,
This Sunday there will be a XX Moscow Team Olympiad, high school students competition based in Moscow that is an elimination contest for All-Russian Team Olympiad. This contest is prepared by Moscow Olympiad Scientific Committee that you may know by Moscow Open Olympiad, Moscow Olympiad for Young Students and Metropolises Olympiad (rounds <a href="https://codeforces.com/blog/entry/21185">327</a>, <a href="https://codeforces.com/blog/entry/23309">342</a>, <a href="https://codeforces.com/blog/entry/43615">345</a>, <a href="https://codeforces.com/blog/entry/47769">376</a>, <a href="https://codeforces.com/blog/entry/50613">401</a>, <a href="https://codeforces.com/blog/entry/54350">433</a>, <a href="https://codeforces.com/blog/entry/55201">441</a>, <a href="https://codeforces.com/blog/entry/57981">466</a>, <a href="https://codeforces.com/blog/entry/58229">469</a>, <a href="https://codeforces.com/blog/entry/61638">507</a>, <a href="https://codeforces.com/blog/entry/62440">51...
competition based in Moscow that is an elimination contest for All-Russian Team
Olympiad. This contest is
Announcement of Codeforces Round 829 (Div. 1)
Announcement of Codeforces Round 829 (Div. 2)
97.
Asia-Pacific Informatics Olympiad 2021 Open Contest Dear Codeforces community,
The **[Asia-Pacific Informatics Olympiad (APIO) 2021](https://apio2021.id/)** is going to take place this month.
<img src="/predownloaded/d6/44/d644de3ae41b008fffe91cf178534a8d54b446ba.png" style="width:250px"/>
We invite everyone to participate in the [APIO 2021 Open Contest](https://open.apio2021.toki.id/).
The open contest will have the same problemset as APIO 2021 and will be held using CMS.
The open contest will be held between [Monday, 24 May 2021 (05:00 UTC+0)](https://www.timeanddate.com/worldclock/fixedtime.html?iso=20210524T05&p1=1440) and [Wednesday, 26 May 2021 (05:00 UTC+0)](https://www.timeanddate.com/worldclock/fixedtime.html?iso=20210526T05&p1=1440).
The duration of the contest is 5 hours, and you can participate at any time within that window.
More details are available on [https://apio2021.id/open.html](https://apio2021.id/open.html). You can register and access the contest on [https://open.apio2021.toki.id/](https://open.apio...
**: The main competition has just ended, and the open contest has just started!
We encourage APIO 2021
98.
Sports Programming or Competitive Programming? Which one should we use?
Competitive Programming is used more often but it has stupid abbreviation (Cerebral Palsy and Child Pornography). Some Youtube accounts about Pokemon Go were actually banned for using that because of Combat Points. [Here](https://www.bbc.com/news/technology-47278362) you can read things like
_"My Club Penguin video had been flagged for sexual content"_. This also means it isn't cool to write _"I'm addicted to CP"_ in any social media.
Urban Dictionary says that SP means Sex Party, but I don't think it's common and at least it isn't something shameful/harmful.
I think the Polish term is "programowanie sportowe" (sports programming) but sometimes we just say English words "competitive programming". The Russian say "Спортивное программирование" (sports programming), in Portuguese it is "Maratona de Programação" (programming marathon). What do you say in your language? In particular, I would like to hear native speakers to state their opinion.
And Sport...
occurrences of SP, e.g. _"The ICPC is the world’s premiere university sports
programmingcompetition"_ on
99.
Greeting and an interview with the legendary Gennady Korotkevich _Hi, Codeforces!_
My name is Una and recently I became a part of the Codeforces team. Unfortunately, I’m not a programmer, but I’m happy to help with other things.
For example, if you win a T-shirt, you'll receive a message asking you to update your personal information, and I do it. ;)
As a new person in this area, I am interested in all the news. Recently I read an interesting interview with the legendary Gennady [user:tourist,2019-06-15] Korotkevich on the ITMO news portal. The interview is dedicated to the victory in the “Science and Life” category of the "TOP 50. The Most Famous People of St. Petersburg" award of the Sobaka.ru magazine. Codeforces team join others in congratulating!
The editors of the portal allowed to share the article on the Codeforces pages (and we are very grateful for this). Original article published at [http://news.ifmo.ru/ru/university_live/achievements/news/8550/](http://news.ifmo.ru/ru/university_live/achievements/news/8550/).
Gennady doesn'...
come to new countries, especially when you meet people you know from other
competitions. I always try, part in programming contests but also had the chance to take part in a math
competition, which I, new person in this area, I am interested in all the news. Recently I read an
interesting interview
100.
Barcelona ACM-ICPC Programming Bootcamp 2017 <div style="float:right;margin:0 1em 1em 1em;text-align:center;">
<a href="http://harbour.space/"><img src="http://d9hhrg4mnvzow.cloudfront.net/in.harbour.space/icpc/2b828bc0-logo-circled-126_02s02s02s02s000000.png"/></a>
<br/><br/><br/>
<a href="http://it-edu.mipt.ru/en/fall_training_2016"><img src="http://d9hhrg4mnvzow.cloudfront.net/in.harbour.space/icpc/569fc7e8-workshop-logo-nodate_04702z04602z000000.png"/></a>
</div>
Hello all.
This coming February of 2017 will be a new experience for me: I'll be one of the coaches who will teach at the
<a href="http://in.harbour.space/icpc/">Barcelona ACM-ICPC Bootcamp</a> hosted by Harbour.Space University. In addition, here are some well-known coaches from our community: [user:Endagorion,2016-12-08], [user:GlebsHP,2016-12-08], [user:Michael,2016-12-08], [user:Jacob,2016-12-08] and [user:snarknews,2016-12-08]. The camp will be hosted in collaboration with Moscow Workshops ACM ICPC by MIPT. The same proven effective studying techniq...
international competitions. This is an appropriate introduction for teams and
studentsnew to the world, -nodate_04702z04602z000000.png"/> Hello all. This coming February of 2017 will
be anew
101.
Balkan Olympiad in Informatics 2014 Problems — Day 1 So Day 1 passed and the problems aren't online. As they were quite tough I decided to put them here and see the community's solutions. I don't have the english papers and I don't have much time to write so I will just describe them shortly and try to include the most useful information.
#### Problem 1 — Diameter
You are given a weighted tree of N nodes and a number K. You must perform a K-partitioning. That is you must choose K non-empty, non-intersecting subsets of nodes that cover all nodes. Each subset is called a partition. A diameter of a partition is the longest distance between a pair of nodes in the partition. A partition doesn't have to be connected, so distance is defined as the distance in the initial tree. A diameter of **partitioning** is the longest diameter of all partitions. Your task is to find the minimum possible diameter of K-partitioning.
**Constraints:**
1<=N<=260,000
1<=K<=N
1<=weight of edges of tree<=1,000
Subtask 1 (10 points) : K=1
...
competition was extended by 45 minutes. However I have reasons to believe the
new tests may not be correct
102.
TON Smart Challenge #5 Is Here! <img alt="TON Smart Challenge" src="https://society.ton.org/_next/image?url=https%3A%2F%2Fstorage.googleapis.com%2Fton-strapi%2FTON_Smart_Challenge_4_18e83679cf%2FTON_Smart_Challenge_4_18e83679cf.png&w=1080&q=75" style="float:right;height: 200px; margin: 10px; max-width:1000%;"/>
Hello, Codeforces!
I'm happy to invite the Codeforces community to join an unusual competition organized by our title sponsor, the [TON Foundation] (https://ton.org/).
The competition will revolve around programming smart-contracts in FunC, native to the TON ecosystem. We invite the Codeforces community to participate in this contest and show that they can not only solve algorithmic problems in rounds but also delve into a new and interesting area.
**Join the contest and master complex cell manipulations, smart contract storage organization, comment handling, basic cryptography, and the logic of governance smart contracts through problem-solving.**
<center style="margin:2.5em;">
<a href="http...
, Codeforces! I'm happy to invite the Codeforces community to join an unusual
competition organized by our, The competition will revolve around programming smart-contracts in FunC, native
to the TON
103.
AtCoder Beginner Contest 151 English Solutions #A — Next Alphabet
The easiest way to deal with this problem is probably to convert the given character to an integer, add one, and convert it back. If you absolutely can't do that, a somewhat more annoying implementation would involve iterating through the alphabet, waiting until you find the given letter, using a boolean variable to store that the letter has been found, and printing the letter on the next iteration of the loop. (However, iterating over the alphabet is itself nasty unless you have conversion from letters to integers, so this approach is rather pointless unless your language just doesn't support the first method, though in that case you should probably switch languages anyway.)
Runtime: $O(1)$. [Click here for my submission.](https://atcoder.jp/contests/abc151/submissions/9440245)
---
#B — Achieve the Goal
In total, we need to earn $NM$ points. We subtract the points earned so far and determine whether this is a valid score for the final ...
a modern programming competition, especially as problem F. Finding the
solution on Google took me
104.
[Video] 10 Ways to Protect your Mental Health in STEM and Academical Competitions Hello Codeforces,
Today I'm going to talk about something that is often overlooked in competitive setups in academics and especially STEM, which is Mental Health. During my competitive years and my life, I often felt very bad about where I was standing and looking back, I realize that things could have gone much better for me if I were to take the right steps.
Over the years, I developed pieces of advice that can help you overcome these issues and while it is not by any means professional advice, it can be very helpful as far as managing the stress of competing at the very top goes. It is something I give a lot of importance to nowadays when coaching people or when I give people advice in general.
[Here](https://youtu.be/I4m_lPdAKRE) is the link to the video.
I would also like to thank everyone who helped me made this video, by listening to my ideas and sharing their stories, which helped me tell things from a broader perspective as far as this topic goes. Their support ha...
before undertaking a new health care regimen, and never disregard professional
medical advice or, questions you may have regarding a medical condition or treatment and before
undertaking anew health care
105.
New competition Mail.Ru Cup. We invite you to participate! 
Mail.Ru Group together with Codeforces invites everyone to take part in the new Mail.Ru Cup competitive programming championship.
Rules
-----
The championship is holding on the Codeforces platform in the format of four rounds: one practice round and three main rounds. Each round is open to all comers. There are no restrictions on participants in any of the rounds.
The practice round is intended for familiarization with the championship platform, participation in it is optional, the results of performances in the practice round do not affect the results of participation in the championship. It is unrated, the duration is 72 hours.
All three main rounds are independent, the results of participation in each of it do not affect the possibility of participation in next rounds. A competitor may take part in any number of main rounds. Each main round lasts 2.5 hours. All of them are open for everyone and r...
New competition Mail.Ru Cup. We invite you to participate!, with Codeforces invites everyone to take part in the new Mail.Ru Cup
competitive programming, “Russian AI Cup”, the competition for machine learning and data analysis “ML
Boot Camp”, the contest, Mail.Ru Group together with Codeforces invites everyone to take part in the new
Mail.Ru Cup
Announcement of Mail.Ru Cup 2018 - Practice Round
106.
Codegoda — Waste of Time (UPD: New Comedy Reply From Support) Today I participated in the coding competition Codegoda hosted by Agoda. I'm not going to talk about their weird rules and coding environment. I just want to share some of my experiences regarding the problemset. In a word, worst experience ever. I just want to mention some things here that seem annoying to me and make me feel it was a waste of time participating in the contest.
Most of the problems require no more than 30 seconds of thinking to get the idea. The problemset was not standard. Expected more quality problems in such a big competition. In the problem of probability, it was mentioned to print up to 5 digits after the decimal point. What does it mean actually? Is it exactly 5 digits? Or at most 5 digits? If it is, then printing more than 5 digits should give wrong answer, right? I printed 10 digits and it passed 3 tests and gave wrong in the 4-th test case. I was thinking my idea/solution is wrong. Then wrote the bruteforce solution and wasted almost 1 hour finding out th...
Codegoda — Waste of Time (UPD: New Comedy Reply From Support), was not standard. Expected more quality problems in such a big competition. In
the problem of, Today I participated in the coding competition Codegoda hosted by Agoda. I'm
not going to talk
107.
Codeforces Round #456 (Div. 2) _Hey, Codeforces!_
Hope that the last few days were quite productive for all of you in terms of rest and pleasure. Time to forget about messing with handle colors and get back to coding!
I'm proud to usher the first contest of the year — Codeforces Round #456, which is going to be held [on Friday, 17:35 MSK](https://www.timeanddate.com/worldclock/fixedtime.html?msg=Codeforces+Round+%23426+%28Div.+2%29&iso=20180105T1735&p1=352&ah=2).
The round will be **rated** for all division 2 participants. Anyway, we will be glad to see whoever decides to join us out-of-competition :)
The authors are — [user:GreenGrape, 2018-01-01] and [user:rek, 2018-01-01] (don't worry, it's all about New Year magic ^^). My heartfelt gratitude to Kolya ([user:KAN, 2018-01-01]) for his invaluable help in round coordination, Grisha ([user:gritukan, 2018-01-01]) and Oleg ([user:x3n, 2018-01-01]) for testing and correcting statements, Dima ([user:cdkrot, 2018-01-05]) and Gleb ([user:glebodin, 2018-01-...
participants. Anyway, we will be glad to see whoever decides to join us out-of-
competition :) The
108.
Codeforces Round #548 (Div. 2) Hi everyone!
I would like to invite you to my second Codeforces round, which I have created with my friends [user:Ashishgup,2019-03-20] and [user:Vivek1998299,2019-03-20].
With that said, I bring to your attention our new [contest:1139] that will take place on [contest_time:1139]. If your rating is less than 2100, this round will be rated for you; otherwise, you can participate out of competition.
I would like to thank [user:Ashishgup,2019-03-20] and [user:Vivek1998299,2019-03-20] for their help with preparing problems, [user:V--gLaSsH0ldEr593--V,2019-03-21], [user:mohammedehab2002,2019-03-21] and [user:Um_nik,2019-03-21] for testing the problems and [user:_kun_,2019-03-20] for coordinating our round. I would also like to thank [user:MikeMirzayanov,2019-03-20] for the awesome Codeforces and Polygon platforms.
You will be given 6 problems and 2 hours to solve them. Scoring distribution will be announced later.
Good luck! :D
**UPD1:** Shortly after the contest, we'll be...
bring to your attention our new [contest:1139] that will take place on
[contest_time:1139]. If your, With that said, I bring to your attention our new [contest:1139] that will take
place on
Announcement of Codeforces Round 548 (Div. 2)
109.
Links of ICPC/CCPC Contests from China **I only update all CCPC contests information and all ICPC contests found in Gym for the first publish so far.**
In recent years, there are two main programming competitions held in China: China Collegiate Programming Contest (CCPC) and International Collegiate Programming Contest (ICPC). These contests are prepared by universities or groups in China and some of them are of very high quality.
Before I was retired, I find it quite hard and annoying to find these contests since they are uploaded in many different websites and some of them might come with wrong data. What's worse, some contests are not allowed to participate virtually or even not been published to any website at all. So I wanna make an aggregation here to help those who are interested in these contests.
I will mainly focus on contests from 2014 — 2020 and I will update it when new contests are published. I hope authors could make comments under this blog to inform me about it.
1.China Collegiate Pro...
mainly focus on contests from 2014 — 2020 and I will update it when new
contests are published. I
110.
2nd Universal Cup. Stage 6: Warsaw Hello Codeforces! I wanted to invite you to participate in the 6th Stage of the 2nd Universal Cup, which will be held from October 21st to 22nd.
The contest is made of problems from the finals of Potyczki Algorytmiczne (a.k.a. Algorithmic Engagements) from the last couple of years, which is the biggest open polish programming competition. There will be two such contests held as Universal Cup stages and in the upcoming weekend you'll be able to face the first of them.
If you participated in any of the PA2020, PA2021, PA2022 or PA special edition **finals**, or happen to know the problems, please don't compete in this contest.
Problems used in the upcoming contest are authored by me and [user:mnbvmar,2023-10-16]. Also a huge round of applause for [user:kostka,2023-10-16], who helped a lot in organization of each edition of PA, coordinated this contest and translated all the statements!
You can participate in the contest in the following time windows:
- 02:00 (UTC) on S...
biggest open polish programming competition. There will be two such contests
held as Universal Cup
111.
North American Championship 2020! New Rules Updated on Oct. 15th **OK the rules are changing again (on Oct. 15th):**
**Eighteen (18) of the 2019 ICPC North America teams will advance to the 2020 ICPC World Finals by meeting at least one of the following criteria:**
**(1) Win the 2020 ICPC North America Championship, (2) Win one of six medals at the 2020 ICPC North America Championship, (3) Win a wildcard slot at the 2020 ICPC North America Championship, or (4) Win one of the eleven 2019 North America Regional Contests.**
(Sorry I am also a bit confused here. (1) is definitely included in (2), and I have no idea about what a wildcard slot is. Does anyone have any idea?)
### Intro
Disclaimer: I am not an official ICPC staff. I write this post just to summarize the information about the North American Championship next year and earn some contribution (sssshhhhhh...!).
Last evening, the information about the North American Championship (NAC for short) is released by the ICPC official.
Finally, the schools in North America can have an ...
North American Championship 2020! New Rules Updated on Oct. 15th, is an onsite competition at Georgia Institute of Technology on February 19-23,
2020, in Atlanta, - This is an onsite competition at Georgia Institute of Technology on February
19-23, 2020, in
112.
ICPC Challenge 2013 <img src="http://212.193.37.254//codeforces/images/icpc_logo.png" style="float: right; margin: 0 0 1em 1em;"/>
Hello everyone,
I guess almost everyone knows that the ICPC Challenge takes place every year before the ICPC World Finals. Of course, this year isn’t an exception. If someone doesn't know, the ICPC Challenge is an additional AI-contest for the ICPC finalists where they have two weeks to solve a single game problem. After that, a [double-elimination tournament](http://en.wikipedia.org/wiki/Double-elimination_tournament) will be held between the team's submissions. The results will be announced at the Finals.
The ICPC Challenge 2013 has started several days ago (on the 3th of June, to be exact) and I want to solemnly declare that this year ICPC Challenge has been prepared by the team from _Baylor University_, _North Carolina State University_ and _Saratov State University_, which I represent! We introduce you a new game called _CodeRunner_.
About the Game
----------...
Finalist teams, we are running a new competition called the **Open ICPC
Challenge**. Thiscompetition, are running a new competition called the **Open ICPC Challenge**. This
competition invites any
113.
(Kind of) A brief overview about the near future of Competitive Programming Think about this. In the near future, let's say 10-15 years, technology will improve drastically, and artificial intelligence (AI) will probably be a very important thing in daily life and work. What would be its effect on Competitive Programming? This topic is not new, Every 1-2 years there's someone talking about it on numerous platforms. And probably all received the same answer: It's dubious, only time will tell us, which is true. But in some way, we can just imagine and make probable guesses about what may happen to CP in the future. This blog will mostly summarize my guesses and questions about the near future of CP, and we can discuss it somewhat to hope for an even better community in the future.
#### **I. Competitive Programming Problems**
One thing we can agree with is in the near future, with a huge potential in the CP community and the existence of AI, the quality of the problems may be better. The knowledge standard will increase over time, to match the improvement o...
will become a big thing in CP. It will help us a lot in thinking about new
problem ideas, hosting, would be its effect on Competitive Programming? This topic is not new, Every
1-2 years there's
114.
Help Team Brazil Participate On-site in EGOI2023 [Click here to donate](https://gogetfunding.com/help-team-brazil-participate-on-site-in-egoi-2023)
<br/>
--------------------------------------------------------------------------------
#### Background
The European Girls' Olympiad in Informatics (EGOI) is a girls' programming competition inspired by the success of the European Girls' Mathematical Olympiad (EGMO).
The format of the competition is similar to competitions such as the International Computer Olympiad and the Central European Computer Olympiad. Several countries around the world are also invited to participate in EGOI, including Brazil, Canada, Egypt, India, Israel, Japan, Mexico, New Zealand, and Peru.
In the first edition of the EGOI, which took place in 2021, all four members of the Brazilian team won medals: one gold, one silver, and two bronze. In EGOI2022, Brazil won a silver medal.
EGOI2023 will be held in Lund, Sweden, from July 15th to July 21st, 2023.
<br/>
-----------------------------------...
/>
--------------------------------------------------------------------------------
#### Background The European Girls' Olympiad in Informatics (EGOI) is a girls'
programmingcompetition, The format of the competition is similar to competitions such as the
International Computer
115.
Codeforces round #525 (Div. 2) Hi!
I'm back with a new contest, a new color, <strike>and a new batch of xor problems</strike>.
Codeforces round #525, rated for the second division, is taking place on [contest_time:1088]. As usual, first division participants can take part out of competition.
I'm the problemsetter of the round. I'd like to thank [user:300iq,2018-12-02] for the great effort coordinating the round, [user:isaf27,2018-12-04], [user:cdkrot,2018-12-04], [user:BudAlNik,2018-12-04], and [user:gritukan,2018-12-04] for testing the round, [user:scanhex,2018-12-04] for translating the statements to Russian, [user:mahmoudbadawy,2018-12-02] for giving his opinions about the problems, and [user:MikeMirzayanov,2018-12-02] for the great codeforces and polygon platforms.
Like my previous [round](https://codeforces.com/contest/959), you'll be given 6 problems and 2 hours to solve them.
After the contest, I'll be on the [community Discord server](https://codeforces.com/blog/entry/52778) to discuss the pro...
Hi! I'm back with a new contest, a new color, and a new batch of xor problems
Announcement of Codeforces Round 525 (Div. 2)
116.
New Year's round... Hello, Codeforces!
------------------
So an unforgettable, rather difficult $2022$ year is coming to the end... However, it is about to be replaced by the long-awaited $2023$, which, I hope, will bring a lot of good both to you, people, and Codeforces...
I, [user:Ilya_Is2022,2022-12-24], am glad to invite you to [contest: 417995] , which will take place already [contest_time: 417995] . Everyone will be able to take part in this round, regardless of the division :)
In the round, you will be expected **5 — 8** tasks on New Year's theme (´｡• ᵕ •｡`). The round will take only **2** hour and **5** minutes, so I **would** **like** you to solve as many problems as possible! The competition will be held in the **ICPC** format, and testing of your solutions will be carried out on the full set of tests provided for the task (⌒‿⌒).
I would like to thank:
- [user:nekstas,2022-12-24] for help in making tasks.
- [user:Alexfil,2022-12-24], [user:Anton_Wars,2022-12-26] for tes...
New Year's round..., will be expected **5 — 8** tasks on New Year's theme (´｡• ᵕ •｡`). The round
will take only **2, ### Enter the competition: [Go. . .](https://codeforces.com/contestInvitation, In the round, you will be expected **5 — 8** tasks on New Year's theme (´｡• ᵕ
•｡`). The round
117.
Web service for defrost standings of competition — S4RiS StanD Good afternoon.
Today I want to share with the public my little project (which was part of my thesis), service on the "defrost" the results of the competition format ACM ICPC — "System for Right Solutions Standings Dancing" (S4RiS StanD).
Hosted on [github](https://github.com/OStrekalovsky/S4RiS-StanD).
#### Introduction
In 2011, my team is still held in the semifinals, where at the close I saw the live operation of such a system ITMO. The feeling was strong. But after analyzing the work and reviewing captured my video, I realized that it is possible to improve this implementation, make it open to and more modest, local competitions, the participants were able to watch in awe tabulation of results. It was chosen as part of my thesis was used already in one competition and received a logical extension.
<p> [cut] </p>
#### About the service and its features
Service is just a web page with a core written in JS and requires no "server" scripts. Therefore, this service ...
Web service for defrost standings of competition — S4RiS StanD, am willing to listen to new proposals, if this development will be in demand., thesis), service on the "defrost" the results of the competition format ACM
ICPC — "System for, — the line with the contestant takes a new position with the currently known
results of other, **UPD:** The new release includes localization. Service now detects a browser
language (which can
118.
Two New Features at the Competitive Programming Hall of Fame Hi Codeforces!
I'm happy to show you two new features, that I've added to the Competitive Programming Hall of Fame website recently. You can find both of them at the [main page](https://cphof.org):
The "Top-100" page allows to see the top performers in major competitions, and the top prize winners.
<spoiler summary="How the Top-100 page looks like">
</spoiler>
The "Advanced" pages contain the lists of participants who advanced to the finals of the upcoming contests. For each of the finalists, there is a bunch of interesting information like ratings and performance history. Most of the columns of the table are sortable. Now there are two advancers lists available: [Finalists of Topcoder Open 2022 Marathon](https://cphof.org/advanced/tco_mar/2022) and [Finalists of Topcoder Open 2022 Algorithm](https://cph...
Two New Features at the Competitive Programming Hall of Fame, Hi Codeforces! I'm happy to show you two new features, that I've added to the
Competitive
119.
My first ACM experience Hey!
Polish Collegiate Team Programming Contest (AMPPZ 2016) took place today, organized by University of Wroclaw. This is my first ACM experience, and I want to share with you my impressions.
To begin with, I'm still a high schooler (2nd grade). However, thanks to generosity of UWroclaw organizers team and some charity institutions, a few best high school teams were able to participate.
Now let's talk about the contest. My teammates were Paweł Burzyński([user:pawelek1,2016-10-29]) and Kacper Kluk ([user:wonrzrzeczny,2016-10-29]). None of us is a really fast coder, so we just decided to focus more on accuracy than speed. As we'll see later, this was kind of a good idea.
The contest started with no delays. I was not expected to be the coding monkey, but somehow it happened that three first and easiest tasks were accepted by me. These were not really challenging, so let's just ignore this fact. Some time later, Kacper scored the "ifologic" problem C. Then, the difficulty ha...
(http://main.edu.pl/en/archive/amppz/2014/fil). While I was adding new and new
ideas to the solution, pillars (http://main.edu.pl/en/archive/amppz/2014/fil). While I was adding new
andnew ideas to the
120.
Egyptian Olympiad in Informatics — Open Contests Archive (IOI style problems) Hello everyone!
I'd like to invite you to [Egyptian Olympiad in Informatics (EOI) — Open Contests Archive](https://codeforces.com/group/swEqtABRxe/) group.
This group contains EOI related competitions (Qualifications, online, onsite contests ,.. etc).
We are compiling some of the older contests and update the group with new competitions.
We would like to thank Coach Mohamed Mahmoud Abd El-Wahab ([user:fegla,2018-08-25]) Head of ACPC Scientific Committee and members of the Committee for preparing the contests.
Also thanks [user:MikeMirzayanov,2018-08-25] for the amazing Codeforces and Polygon platforms.
Contests that are currently available:
<spoiler summary="EOI 2019 (Secondary Division)">
[Egyptian Olympiad in Informatics (EOI) 2019 — Onsite Day Two (Secondary Division)](https://codeforces.com/group/swEqtABRxe/contest/253469)
[Egyptian Olympiad in Informatics (EOI) 2019 — Onsite Day One (Secondary Division)](https://codeforces.com/group/swEqtA...
We are compiling some of the older contests and update the group with new
competitions.
121.
December Cook-Off CodeChef invites you to participate in [the December Cook-off 2014](http://www.codechef.com/COOK53).
**Time**: 21st December 2014 (2130 hrs) to 22nd December 2014 (0000 hrs). (IST — +5:30 GMT) — Check your [timezone](http://www.timeanddate.com/worldclock/fixedtime.html?msg=December+Cook-Off+2014&iso=20141221T1600&ah=2&am=30).
[Details](http://www.codechef.com/COOK53)
Registration</b>: Just need to have a CodeChef user id to participate.
New users can register <a target="_blank" href="http://www.codechef.com/user/register/">here</a>.
<br />
**Problem Setter**: [user:Rubanenko,2014-07-20]
**Problem Tester**: [user:tuananh93,2014-07-20]
**Russian Translators**: [user:vadimmm,2014-12-21] & [user:Rubanenko,2014-12-21]
**Editorialist**: [user:elfus0,2014-07-20]
**Mandarin Translator**: [user:xiaodao,2014-07-20]
It's my third CodeChef Cook-Off. The contest is quite balanced and I think that this contest will bring you something new and unusua...
bring you something new and unusual. Don't be afraid of being creative! As
always I'd love to hear, ) Registration: Just need to have a CodeChef user id to participate. New users
can register
122.
My winning theory in IOI 2018 & 2019 — Why I won 2 golds in IOI Dear Codeforces community.<br />
According to [IOI 2019 Results](http://stats.ioinformatics.org/results/2019), I got the 25th place and got successful gold medals twice in a row.<br />
Although it was pretty close to the gold-medal border (only 6.14pts / 600 difference) and it was lower performance than IOI 2018, which I participated when I was orange in Codeforces, I had many chances to get more points in this IOI, even for top 10. Since there are not so many people who have got two gold medals in IOI (and there were many requests like "I want [user:E869120,2019-08-14] to talk about how to get gold in IOI" like [this comment](https://codeforces.com/blog/entry/66909?#comment-510127) and [this comment](https://codeforces.com/blog/entry/66909?#comment-513129)). I want to write something about IOI, which may be useful for people who will participate in IOI next year and also some years later.<br />
<br />
<br />
### A. First of all
At...
, if you have no time to solve all of them, I recommend solving new one. **If
you did virtual
123.
Codeforces Month of Blog Posts Results One and a half months ago [I proposed a challenge](https://codeforces.com/blog/entry/110840) to every one of you to get something from your drafts or from your head and actually write a blog post about it. I got a bunch of submissions, and you can find the links to all of them throughout this blog post (I was actually surprised that all entries were meaningful and interesting, so I definitely recommend checking them out). If you submitted an entry and I didn't mention it here, it is not purposeful! Indicate it via a direct message and I will include it here. It was just a bit hard to keep track of all submissions.
I went through all the submissions. Some of them were very complicated, and I tried my best to get the overall idea but I will need to come back to dive deeper into some technical proofs. However, I believe that these technicalities that I glanced through do not affect my decisions. We are ready to present the winners!
Regarding the first place, there was no doubt in my...
on combinatorial problems. For me even the online FFT part was new, and even
though it was already, wildcards one was new to me. - [Centroid decomposition for very sparse
graphs](https://codeforces.com/blog
124.
You have free time — read this blog ;) Hello everybody !
School is finished. I am in the village. I don't have fast internet and I won't do next competition :(
But, I can write new topic with my 'potato' English with no word HELP ( so you can relax and read next part :D ) !
During this break I plan to learn a lot of things. First I start with learning C++ . Pascal is great language and help me a lot, but without C++ you can't do something very fast and good on the competitions (when I had to write some algorithm with graphs (even dfs) or I had to write SET , always i said — NO WAY , GO TO NEXT TASK ). Now I will change it and no more crying for bad results :)
I also plan to learn many graphs and string algorithms ( now a know 4-5 graphs algo. , KMP and hashing ( everything harder I do with hashing), also I know trie but it wasn't necessary to coding it on any contest ). Normally I plan to do every competition on the summer :D
What will you do during vacation ?
Second part of this blog is about pre...
won't do next competition :( But, I can write new topic with my 'potato'
English with no word HELP, competition :( But, I can write new topic with my 'potato' English with no word
HELP ( so you can relax and
125.
CROC-MBTU 2012, Elimination Round Good day!
Elimination round of the CROC Collegiate Programming Competition for the MSTU Bauman students is going to be here soon. The official championship participants will take part in the competition, all others will be out of the competition in the table of results.
The contest is held by the well-known rules ACM-ICPC. Competition duration is 2:00 hours. Supported programming languages are C/C++, Pascal, Java, C#, Python, Ruby, PHP, Haskell, Scala, OCaml, and D.
This Round will be the rated for the Div-2 participants, regardless of whether one is the competition championship party or not. For Div-1 participants this round is unrated.
Please note that the official participants of the competition are not need to register for this competition they will be registered automatically (with advance registration at [website] (http://www.crocok.ru/championship/)).
Good luck to everyone!
**UPD.** Competition is completed, thank you very much for your participation! I hope th...
Good day! Elimination round of the CROC Collegiate Programming Competition for
the MSTU Bauman
Announcement of CROC-MBTU 2012, Elimination Round (ACM-ICPC)
126.
MathForces Saturday Round! Hello Codeforces!
On [Saturday Feb 24 at 12:00 PM EST](https://www.timeanddate.com/worldclock/fixedtime.html?msg=Div+3+Math-Flavored+Coding+Competition&iso=20240224T0900&p1=224&ah=2) we will host a **<span style="color:green">Combinatorics MathDash Contest</span>** co-hosted by the Carnegie Mellon Informatics and Mathematics Competition! — <span style="color:green"><b><u>[Register here](https://mathdash.live/cmimc2023-combo)</u></b></span>
On [Tuesday Feb 27 at 7:00 PM EST](https://www.timeanddate.com/worldclock/fixedtime.html?msg=Div+3+Math-Flavored+Coding+Competition&iso=20240227T1600&p1=224&ah=2) we will host the seventh **<span style="color:green">MathDash Contest!</span>** — <span style="color:green"><b><u>[Register here](https://mathdash.live/contests)</u></b></span>
Brought to you by the creators of [Breez Math Training](http://breez.live), we have extensive experience teaching competition math (participants of the USA Math Olympiad Program) as well as p...
/fixedtime.html?msg=Div+3+Math-Flavored+Coding+Competition
&iso=20240224T0900&p1=224&ah=2) we will
127.
Complaints on Comments <img src="/predownloaded/f0/ff/f0ff581246db486e2d6a28398f591770f01a0747.png" style="width: 400px; float: right; margin: 0 1em 1em 1em;"/>
Hello!
Now, if you've downvoted a comment, you can report it. You should do this if you're certain that one of the rules is being violated. Currently, the list of rules is as follows:
* <b>Hate/Offensive</b>: The publication contains signs of hatred, racial slurs, derogatory language or intolerance. Please maintain a respectful tone; critical comments should include thoughtful reasoning.
* <b>Threats/Harassment</b>: Content that contains explicit threats or harassment, including cyberbullying or stalking, is subject to censorship. Codeforces aims to create a safe and respectful environment for its users.
* <b>Vi...
already been discussed, and a new discussion will not bring anything new. The
author can find answers, . * Duplicate content: This content has already been discussed, and a new
128.
TCO21 Round 1A The first Online Round of the [2021 Topcoder Open](http://tco21.topcoder.com/) Algorithm Competition has arrived! Round 1A will be held on [Saturday April 17, 2021 at 12:00 UTC -4](https://www.timeanddate.com/worldclock/fixedtime.html?msg=TCO21+Algorithm+Round+1A&iso=20210417T12&p1=98) and you are invited to compete.
**How many will qualify?**
The 750 highest scorers from each Round 1 will win a spot in Round 2 of the Algorithm Competition.
**How to Compete?**
Please note that you must register for this round in the [Arena or Applet](https://www.topcoder.com/community/arena).
Registration is open for the round and closes at 11:55 UTC -4. Be sure you register early to guarantee your spot in the round as registration is limited to the first 2,500 competitors. Please take a look at our [*How to Compete* guide](https://www.topcoder.com/thrive/articles/How%20To%20Compete%20in%20SRMs) to understand Topcoder Algorithm rounds better.
Don't forget! There will ...
**New to Topcoder and the TCO21**? The Algorithm Competition is one of the most
fierce and popular, Competition has arrived! Round 1A will be held on [Saturday April 17, 2021 at
12:00 UTC -4](https
129.
Overview of the Moscow International Workshop @MIPT Recently I returned from the Workshop and wanna share my impressions.
The post will be divided into several parts depending on an aspect I am covering in it.
[cut]
<be/>
####**Place**<br/>
The Workshop is held entirely in MIPT: contestants live in MIPT dorm and have the trainings&lectures at MIPT study buildings. The most distant points in this system are at most five minutes from each other and it was really nice, since one shouldn't care about getting up 30 minutes earlier in order to come to the contest in time. <br/>
In CIS the word "dorm" itself is quite scary, because almost everybody has a vivid experience of coming to some competition to some city called N-vodsk and living in cold, stinky dorm with no water or something like this. However, all the contestants were settled in a new dorm, which was pretty nice and comfortable as for a dorm. I had four guys, including me, living in a two-rooms flat with kitchen and bath.<br/>
Canteen... Well, as for CIS, it was OK, b...
scary, because almost everybody has a vivid experience of coming to some
competition to some city
130.
Fixing the contest management mess ...or "How legacy systems fight obstacles no sane person would introduce in the first place".
Hello, Codeforces!
I am sure that those of you who tried to host their own programming competitions or write their own utilities for contest management are aware of the state of affairs regarding contest hosting. There are lots of incompatible formats, no one knows exactly how stuff ought to work, Polygon is full of nondescript and seemingly contradictory options, ej-polygon never seems to work quite correctly, modifications have to be applied to jury archives to make them work on your particular installation, non-trivial problem types require constant maintenance and hacks, *ad infinitum*.
Personally, I stumbled upon all these problems when I tried to get my own judge system working and suddenly discovered that the difficult part is not judging complex problems, but handling artificial complexity introduced by legacy software and standards. So here I am, attempting to solve these pro...
problems. --- Firstly, I introduce a new format, which I shall call
**problem.xml format
131.
Facebook Hacker Cup 2020: Qualification Round **The Qualification Round of the 2020 Facebook Hacker Cup is less than 48 hours away!**
The round will begin on [**July 24th, 2020 at 10am PDT**](https://www.timeanddate.com/worldclock/fixedtime.html?msg=Facebook+Hacker+Cup+2020+-+Qualification+Round&iso=20200724T10&p1=224) and will last for **72 hours (3 days)**. The contest can be found on [**Hacker Cup's new competition site**](https://www.facebook.com/codingcompetitions/hacker-cup/2020/qualification-round).
**Everyone who solves at least one problem correctly will advance to Round 1**, which will take place on August 15th. Please note that all submission judgments will only be revealed after the round ends. More details about rules and other information can be found in the [FAQ](https://www.facebook.com/codingcompetitions/hacker-cup/2020/qualification-round/faq).
Registration will remain open on the contest page until the end of the Qualification Round. Once you've registered, you may wish to confirm that the information i...
**72 hours (3 days)**. The contest can be found on [**Hacker Cup's new
competition site**](https, last for **72 hours (3 days)**. The contest can be found on [**Hacker Cup's new
competition site
132.
Barcelona Bootcamp — Teams and Sponsorship update <img src="/predownloaded/a6/1b/a61be4b7ba01cf0feb68d6e5e00eb9d467fe8519.png" style="float:right;">
For the last 6 years the world titles have been won only by St Petersburg teams – ITMO and St. Petersburg State University – both universities will bring their top teams to [2nd Hello Barcelona Programming Bootcamp in collaboration with Moscow Workshops ACM ICPC](http://in.harbour.space/icpc/acm-icpc-hello-barcelona-bootcamp-autumn-2017/?utm_source=Codeforces)
The event runs from Sept 27 to Oct 5 – but how to get the most out of the camp?
"I think there is no universal solution for "get the most out of a camp" – everyone should find their own path, but the general guideline will be: communicate with other participants as much as you can, make sure you do upsolving (at least some), keep track of how much you sleep," said [Gleb Evstropov](https://goo.gl/srpKTu), coach and coordinator of the programming committee.
Sleeping could be somewhat challenging with all the famous Russian ...
exist at the intersection of crowdsourcing, competition and social networking.
The HeroX
133.
2023 Recap Happy New Year to everyone who's already stepped into 2024, and to those of us still hanging out in 2023! I usually like to spend a bit of time looking back at the year that's been. So, let's dive into this little trip down memory lane together and see what 2023 had in store for us!
- On January 19th, the [Universal Cup](https://ucup.ac/) was launched as an alternative to the OpenCup, primarily to facilitate systematic training for teams with a focus on preparing for the International Collegiate Programming Contest (ICPC). In its inaugural season, the Universal Cup attracted participation from 750 teams, representing over 300 organizations worldwide, which participated in 22 stages.
- From February 18th to 26th, the first edition of the [Osijek Competitive Programming Camp](https://ocpc.mathos.unios.hr/) took place. A total of 74 teams participated, with 13 teams attending the event in person in Osijek, Croatia. The second edition of the camp occurred in September.
- Also in Febr...
Happy New Year to everyone who's already stepped into 2024, and to those of us
still hanging out in
134.
Petition to Restrict the Coach Mode Authority Tighter Happy New year, Codeforces.
I had this idea for about a month. I heard problem setters complaining about some people used their coach mode authority to enlarge some problems' TL in the Gym just for letting their submissions passed. What's worse, these guys even forgot to change it back, which causes some troubles for participants afterwards.
Moreover, I also have similar experience. Back in 2020, I did [SWERC2019](https://codeforces.com/gym/102501/) with my friends. Then after a few days, I returned and found that my competition record disappeared from the scoreboard. Someone must press the 'to practice' or 'devirtualize' button. If you press those buttons, the website will ask you if you confirm your action (which is not reversible). Therefore, I pretty sure there is someone who just don't want to see my partipation record on the scoreboard for some reasons that I could never realize.
Just in case some of you don't know (maybe hasn't discovered yet) what the coach mode can do...
Happy New year, Codeforces. I had this idea for about a month. I heard problem
setters
135.
Polygon: resources advanced properties (graders) Hello, Codeforces!
Today I’ve released an important update of the Polygon — partial support for advanced properties of resources. The main task that is being solved by this update is to support the development of problems with graders.
In most competitions, participants need to submit a complete solution code, including reading an input reading and an output writing. For example, in Codeforces rounds you solve such kind of problems. However, in some competitions another approach is using: a participant needs to implement the required function or interface.
For example, in a problem statement can be written that in a C ++ solution you need to implement a function that has prototype `int sum (int a, int b)` and submit the implementation. In this case, a participant has to submit a source code that contains the implementation of this function. Then, in the process of judging this solution for such a problem, an online judge should compile and link into a single executable f...
feature will help the scientific committee to write new problems. And I wish
participants every success
136.
My competition shirts are now gym wear Hi, it has been a long time since I've last posted anything here and, as usual, I'll talk more on the human level rather than just being a technical post.
The fate of every competitive programmer is someday (hopefully far for now) you'll retire! The reasons behind it can be multiple.
- You got a fulltime job
- You graduated
- You got kids or
- You are just sick of getting hacked on 2 out of the mere 4 questions you passed on every god damn contest!
The fact is: now you are getting rusty, slow and dumb. You may think that's not that bad. Your coworkers still didn't put as many struggling hours of problem-solving as you did in the past, you can still solve hard questions that everyone just gives up right away, you are really good in understanding the head of your partners in code and can fix their bugs by just clearing their heads and helping them out. But that's just you lowering the bar and getting used to the software development life unconsciously.
If you think abo...
My competition shirts are now gym wear, learn new things to be productive on., reliable product instead of targeting a new problem every day. And that's not
all bad. You are, scalable, fast and reliable product instead of targeting a new problem every
day., And that's not all bad. You are learning new things. Software development
useful things. But your
137.
ICPC East Asia Pacific Semifinal from 2020/2021 Season Hi! In Korea Regional ICPC homepage, news about ICPC East Asia Pacific Semifinal has appeared. I didn't found any other articles about this, so I'll upload this to get some contribution.
> There will be a semi-final competition in the East Asia-Pacific region between the Regional Contest and the World Final. The official title is undecided, but the semifinals will be held in Vietnam on December 21-23, 2020. Up to this year, we are selecting teams to advance to the world competitions, but starting next year, some will be selected at the regional competitions and some will be selected at the semifinals. Unlike the World Championships, the semifinals are expected to allow multiple teams, with an upper limit on the number of teams in each university. The East Asia-Pacific region includes Korea, Taiwan, Japan, Southeast Asia such as Vietnam, the Philippines and Indonesia, and Oceania such as Australia and New Zealand.
[Original post](http://icpckorea.org/archives/1921)
Great to see...
will be a semi-final competition in the East Asia-Pacific region between the
Regional Contest and the, > There will be a semi-final competition in the East Asia-Pacific region
between the Regional
138.
Design competition for Codeforces T-shirts Hi, Codeforces! Glad to announce a design competition for Codeforces T-shirts:)
Conditions:
- Design must reflec- t belonging to Codeforces community.
- Short and brief motto is important. Phrase outline can be an additional instrument for expression of idea. An interesting motto can also participate in the competition.
- Idea is important for a printing. It's not neccessary to implement it fully if you don't feel your skill level right. You can describe your idea with a sketch/text description and that would be enough.
- T-shirt's background can be white or black.
- The winner will be determined by Codeforces team according to community opinion.
We consider this options as good ones:
<img src="/predownloaded/87/55/87558891e5ddc780e56f8db4fac167a8a45b52ea.png">
<img src="/predownloaded/2b/c0/2bc0f2ad5d8107c449c3f6c08870b16244cbe94e.png">
We're waiting for your options during this two weeks. Last day – 14 February. We'll send 3...
Design competition for Codeforces T-shirts, with new design to the winner!, Hi, Codeforces! Glad to announce a design competition for Codeforces T-shirts:)
Conditions
139.
Northern Eurasia Finals 2018 Olá a todos!
<img src="/predownloaded/a3/af/a3afaa7ef284be4ce1de9c89fd544778f4f2c828.jpg" align="right" style="height: 260px; margin: 10px;" alt="text"/>
<a style="font-size: 20.0px;padding: 8.0px 14.0px;background-color: rgb(55, 109, 171);color: white;" href="http://neerc.ifmo.ru/archive/2018/standings.html">Current Standings</a>
The first winter weekend of the year would be tough for students who arrive to St. Petersburg, Barnaul, Almaty and Tbilisi. On the 1-2 of December ITMO University, Altai State Technical University, European University and Kazakh-British Technical University will host the final contest of [Northern Eurasia] (http://neerc.ifmo.ru). Participants are going to face a serious competition – they will fight for the right to represent their university on the finals of the [ICPC 2019] (https://icpc2019.up.pt/) in April in Portugal.
At the ITMO University stage we also expect 131 teams, including the Champions and Vice-Champions (but, worth mentioning, NEERC...
Stay tuned for the latest news and monitors from the competition! These guys
will go to the Porto
140.
Codeforces Round #390 (Div. 2) THi Codeforces!
I'm glad to announce that [today at 17:35 MSK](https://www.timeanddate.com/worldclock/fixedtime.html?msg=Codeforces+Round+%23390&iso=20170106T1735&p1=166&ah=2) will take place first round in the new year — Codeforces Round #390 for the second division. Traditionally, first division participants will be able to take part out of competition.
Round was prepared by me, Alex [user:netman,2017-01-06] Vistyazh.
Many thanks to Nikolay [user:KAN,2017-01-06] Kalinin for his help in contest preparation and Mike [user:MikeMirzayanov,2017-01-06] Mirzayanov for the Codeforces and Polygon platforms.
You will be offered five problems and two hours to solve them.
Scoring will be announced closer to beginning of the round.
**UPD:** Scoring is **500 — 1000 — 1500 — 2000 — 2500**
**UPD2:**
There were some troubles during contest — in problem C first pretest wasn't equal to first sample, and unfortunately this problem was solved ...
/fixedtime.html?msg=Codeforces+Round+%23390&iso=20170106T1735&p1=166&ah=2) will
take place first round in thenew
Announcement of Codeforces Round 390 (Div. 2)
141.
Timus Charts 1.0: a new version for most of popular browsers <div style="text-align:center;"><img align="center" src="http://habrastorage.org/files/219/cd9/e48/219cd9e482914d6095e52749f4aa3d82.png" /></div>
<strong>Timus Charts</strong> is an extension for a browser that adds a chart of count of solved problems to [Timus Online Judge's](http://acm.timus.ru/) profiles. With it, you can observe users' activity and, if they solve problems regularly, compare their experience at various times. In addition, the extension slightly changes colors in the problems map to improve it's usability.
[cut]
<br /><br />
The new version adds several new features, fixes some bugs, and supports most of popular browsers:
* You can add more users to the chart.
* Loading of the chart has sped up due to using API and caching data. If your visited the current profile before, only a few count of last submits will be queried. If count of solved problems isn't changed after previous visit, no queries will be executed at all.
* You can hide the chart (it won'...
Timus Charts 1.0: a new version for most of popular browsers, problems map to improve it's usability. [cut]
The new version adds several new features
142.
Why do users make multiple accounts? I will attempt to explain why I think people do this, and hopefully start a serious examination of how to deal with the problem...
~~~~~
struct Warning{
long long story;
};
~~~~~
Label:
Meet Bob. Bob has always been a pretty bright individual. Deciding that he should use his intelligence for good, Bob decided to put his skills to the test. As Bob knows, people use computers for programming. Because Bob owns a computer, he figures he must be a programmer as well. So Bob decided he was going to create the best game ever — one that would inspire a generation of children to waste their lives chasing pixels — solely with the power of his mind. Absolutely sure of how to continue, Bob promptly opened up the command prompt. This made sense to Bob because he once saw a monospaced screen in a movie where some dude hacked the government in 90 seconds. He proceeded to type in his masterpiece:
~~~~~
open a new window
make the background look like trees
put a guy w...
competition, with a new rating of 1701. Bob had never been happier in his life.
Newly confident in his
143.
School Individual Contest #1 (WCS 2010/11) - Codeforces Beta Round #38 (ACM-ICPC Rules) Hello everybody.<br><br>I would like to invite you to <span class="wl-st" id="wl-st-number1"></span><span class="dct-tt">participate</span> in a new competition, that will be held on the 30th of October at 16:00 MSK. It will be a part of the series of winter programming school olympiads, but it will be only a standart Codeforces round for adult participants.<br><br>Teams aren't invited, only single members. The official rules will be ACM-ICPC.<br>Jury has decided to increase the duration of the competition, which will be <b>4 hours</b> long.<br><br><h3>Attention: <span class="comment-content-13116">People, who <span class="comment-content-13113">are considered out of competition, are participants of </span>Codeforces Round #38, others are participants of School Personal Contest #1. But we will use<b> <u><i>merged result table</i></u></b> for updating rating.</span></h3><br>The authors are me, Mike Mirzayanov and Artem Rakhov. Also I'm expressing <span class="dct-tt">gratitude to <...
">participate in a new competition, that will be held on the 30th of
144.
Codeforces Round #693 (Div. 3) Happy New Year, Codeforces!
UPD: _**We have received such different opinions about the order of problems, that we cannot be completely sure about it. We recommend you to read all the problems and do not strongly hope that the difficulty for you necessarily coincides with the order in the round.**_
\<almost-copy-pasted-part\>
Hello! [Codeforces Round #693 (Div. 3)](https://codeforces.com/contest/1472) will start at [contest_time:1472]. You will be offered 7 problems with expected difficulties to compose an interesting competition for participants with ratings up to 1600. However, all of you who wish to take part and have a rating 1600 or higher, can register for the round unofficially.
The round will be hosted by rules of educational rounds (extended ICPC). Thus, during the round, solutions will be judged on preliminary tests, and after the round it will be a 12-hour phase of open hacks. We tried to make strong tests — just like you will be upset if many solutions fail after t...
Happy New Year, Codeforces! UPD: _**We have received such different opinions
about the order of
Announcement of Codeforces Round 693 (Div. 3)
145.
Beta Round #4 — csacademy.com Hello, Codeforces!
We are happy to announce that we're going to host a new contest at [csacademy.com](http://csacademy.com). Once again we'd like to thank all our users for the great feedback they provide. We try to listen to your advice and improve our platform with each competition.
Our [Beta Round #4](https://csacademy.com/contest/beta-round-4/) will take place on [Tuesday, Apr/26/2016 16:00 (UTC)](http://www.timeanddate.com/worldclock/fixedtime.html?msg=CSAcademy+Beta+Round+4&iso=20160426T16&p1=1440&ah=2). If you want to take part in this round you need to [register](https://csacademy.com/contest/beta-round-4/) before the contest begins. You can access the chat room for this round [here](https://csacademy.com/contest/beta-round-4/#chat) (login required). Initially we were planning on having two divisions starting with this round. After taking a closer look at the rankings we decided it's too early to separate our users. So this round will be a Div1 + Div2, with 3 easy tasks a...
We are happy to announce that we're going to host a new contest at
[csacademy.com](http
146.
Invitation to Goodbye Renyin Hello, Codeforces!
It’s our pleasure to invite you to [Goodbye Renyin](https://uoj.ac/contest/80), which takes place on [Friday, January 20, 2023 at 13:00<sup title="timezone offset" style="font-size:8px;">UTC+8</sup>](https://www.timeanddate.com/worldclock/fixedtime.html?msg=The+contest+will+hold+at&iso=20230120T13&p1=33&ah=5).
You will have 5 hours to solve 5 problems sorted roughly by difficulty. Each problem is worth 100 points and may have several subtasks. There might be interactive or output-only problems. The contest is open to everyone, though Codeforces-Div. 1-level contestants are more likely to enjoy it. For details, you may check last year’s [Goodbye Xinchou](https://uoj.ac/contest/74) (only available in Chinese, Simplified).
The problems are authored by [user:changruinian2020,2023-01-17], [user:ix35,2023-01-17], [user:flowerletter,2023-01-17], [user:Melania,2023-01-17] and [user:qingyu,2023-01-17].
The competition format will be similar to (but a bit different...
-01-17] and [user:qingyu,2023-01-17]. The competition format will be similar to
(but a bit
147.
Unbelieveable story of success at ACM ICPC final Preparing to contest
====================
For long time I haven't been writing stories about my life. As Nietzsche said — Bredor died, and I don't feel
so good myself. You might be thinking that I went into booze.
Actually, I have really been drinking so much all this time, but I had more important activities: once upon a time I came to my college to find a company to drink. There I saw an advertisment about programming competitions, but I found that competitive programming is sense less in school and it didn't attract my attention. Soon, I was summoned to the dean, and the dean told me: "mr. Rudolph Gotov, there is noone except you who can win this contest!". I refused him at first time certainly, but then he offered me hard choices such as to continue winning all contests or to stop to arrange night parties at college campus. The choice was not great, and I went looking for a team. Because of stupid rules I could not invite my friends from Bratsk into the team, so I had t...
role in our success, and we went to the finals of the international competition
ACM-ICPC (wtf what
148.
Kotlin Heroes 6 Announcement <img src="/predownloaded/6b/62/6b62332b37519ade4a4d42cb266937c422b64557.png" style="width:500px;float:right;margin:0 1em 1em 1em;"/>
Hello, Codeforces!
First and foremost, we would like to say a massive thank you to everyone who entered and submitted their answers to the five Kotlin Heroes competitions which were held previously: [Episode 1](https://codeforces.com/contests/1170), [Episode 2](https://codeforces.com/contests/1211), [Episode 3](https://codeforces.com/contests/1297), [Episode 4](https://codeforces.com/contests/1346), and [Episode 5: ICPC Round](https://codeforces.com/contest/1431).
Ready to challenge yourself to do better? The [contest:1488] competition will be hosted on the Codeforces platform on [contest_time:1488]. The contest will last 2 hours 30 minutes and will feature a set of problems from simple ones, designed to be solvable by anyone, to hard ones, to make it interesting for seasoned competitive programmers.
**Prizes:**
**Top three winners will ge...
/contest/1431). Ready to challenge yourself to do better? The [contest:1488]
competition will be hosted
Announcement of Kotlin Heroes: Episode 6
Announcement of Kotlin Heroes: Practice 6
149.
Invitation to Indigo Coding Competition ($700+ worth of Prizes) Hello Codeforces!
I tested this contest and I found it of a high quality especially for the div2/div3 participants, and at the request of the organizers, I am sharing the announcement in order to promote it here. The announcement starts below.
Hi all! This is slightly short notice, but if you are interested in a great challenge, you should definitely sign up!
The **Indigo Coding Competition** will be happening tomorrow on [Saturday, April 15th, from 4:30 to 7:00 PM EST!](http://www.timeanddate.com/worldclock/fixedtime.html?msg=Indigo+Coding+Competition&iso=20230415T1630&p1=3918&ah=2&am=30) and it will be held on [HackerRank](https://www.hackerrank.com/indigo-coding-competition).
In order to participate, you need to complete [the google form](https://forms.gle/MxDsZTs4S1jE98Qf8) and check out the information from [the contest website](https://indigocode.org/).
Designed and organized by high school and college students from...
Invitation to Indigo Coding Competition ($700+ worth of Prizes), **), meet new people, solve some cool problems, and have fun! If you're
interested, check out the website, Competition** will be happening tomorrow on [Saturday, April 15th, from 4:30 to
7:00 PM EST!](http
150.
Yandex.Algorithm Test Round Analysis Test Round and its analysis were prepared by [user:snarknews,2013-07-07] and [user:Gassa,2013-07-07]. Problems of the Test Round have already been used before in different competitions. The following rounds will consist of new original problems, and you can still [register](http://algorithm.contest.yandex.com/register/) and compete in the [Qualification Round](http://algorithm.contest.yandex.com/contest/307/enter/).
During the round a lot of participants tried to make "blind" submits, from time to time even going to the top places, but as the system tests showed with only one problem solved in fact.
By the end of the round [user:tourist,2013-07-07] was at the first place with all problems but B submitted "blind". [user:vepifanov,2013-07-07] was at the second place with A, C and D submitted "blind", but B and F — submitted "open" (both with a wrong attempt), [user:Anton_Lunyov,2013-07-07] was at the third place with only C submitted "blind". All other participants had less ...
rounds will consist of new original problems, and you can still [register](http
151.
Beta Round #5 — csacademy.com Hello, Codeforces!
We are happy to announce that we're going to host a new contest at [csacademy.com](http://csacademy.com). From now on we're going to have a competition every two weeks, so here we go:
[Beta Round #5](https://csacademy.com/contest/beta-round-5/) will take place on [Monday, May/09/2016 16:00 (UTC)](http://www.timeanddate.com/worldclock/fixedtime.html?msg=CSAcademy+Beta+Round+5&iso=20160509T16&p1=1440&ah=2). If you want to take part in this round you need to [register](https://csacademy.com/contest/beta-round-5/) before the contest begins. Just like the [previous round](https://csacademy.com/contest/beta-round-4/), this will be a Div1 + Div2, with 6 tasks of varied difficulty.
#### Platform changes since Beta Round #4:
- **IMPORTANT:** When the contest starts the page will automatically load the tasks and open the first problem for you. Please don't refresh the page, as this will probably overload the server.
- We fixed the editor buttons bug. Now you can s...
We are happy to announce that we're going to host a new contest at
[csacademy.com](http
152.
Helping the Tunisian National Team participate in the on-site IOI 2022 Hello Codeforces community,
[Click here to Donate](https://www.cha9a9a.tn/fund/detail/the-international-olympiad-in-informatics-ioi-329777)
My name is Amir Elarbi and I'm a member of the Tunisian IOI 2022 team along with Amine Ouesleti ([user:StrawHatWess,2022-07-05]), Hedi Chehaidar ([user:HediChehaidar,2022-07-05]) and Mohamed Ali Saidane ([user:MohamedAliSaidane,2022-07-05]).
I want to start by expressing my sincere gratitude for this opportunity. Representing Tunisia in one of the most important **international science Olympiads** has been a dream of mine ever since I started my journey with the national team.
Of course, **participating in the IOI wouldn't be the same without the on-site experience.**
Naturally, the goal of IOI goes beyond the competition itself and instead centers on the complete experience, which includes meeting others who share your interests, discovering new cultures, going on excursions, and much more.
As you may know, travel expenses to r...
Naturally, the goal of IOI goes beyond the competition itself and instead
centers on the complete
153.
TCO20 Round 1A The first Algorithm Competition Online Round of the [2020 Topcoder Open](http://tco20.topcoder.com/) has arrived! Round 1A will be held on [Saturday April 18, 2020 at 12:00 UTC -4](https://www.timeanddate.com/worldclock/fixedtime.html?msg=TCO20+Algorithm+Round+1A&iso=20200418T12&p1=98).
**Did you win an _Automatic Berth a.k.a Bye_ for Round 1?**
Check out the members who won an automatic berth to Round 2 [here](https://tco20.topcoder.com/competition-overview/algorithm/algorithm-byes). **CORRECTED and UPDATED**
**How many will qualify?**
The 750 highest scorers from each Round 1 will win a spot in Round 2 of the Algorithm Competition.
**How to Compete?**
Please note that you must register for this round in the [Arena](http://arena.topcoder.com/) or [Applet](http://topcodr.co/javaarena). Registration is open for the round and closes at 11:55 UTC -4. Be sure you register early to guarantee your spot in the round as registration is limited to the first 2,500 co...
New to Topcoder and the TCO20? The Algorithm Competition is one of the most
fierce and popular
154.
TLX Open Contest Beta Round #1 — Invitation Hi all,
This year, Indonesia is hosting [Asia-Pacific Informatics Olympiad 2015](http://apio2015.org/). For this competition, we will use our brand new contest system called [TLX](https://competition.ia-toki.org/). We have been using TLX intensively for Indonesian training camps and so far we have been very satisfied and no major problems were encountered.
Now, we would like to conduct a real-time test for international usage. So, we invite you to take part in **TLX Open Contest Round #1**. Here are the details:
- Saturday, April 25 20.00 UTC+7 — 23.00 UTC+7 (3 hours) [timeanddate](https://www.timeanddate.com/worldclock/fixedtime.html?msg=TLX+Open+Contest+Beta+Round+%231&iso=20150425T20&p1=108&ah=3).
- You have to register to TLX (there is an SSO login system), and then register to the contest.
- Contest registration closes 5 minutes before contest **ends**.
- IOI-style, 3 problems. There will be subtasks. For this testing round, we will be using past Indonesian olymp...
this competition, we will use our brand new contest system called
[TLX](https://competition.ia
155.
Invitation to Codenight 2020 Hello Codeforces!
Hack36 2020 and Computer Club, MNNIT Allahabad, India are glad to invite you to the first edition of a new programming competition of MNNIT Allahabad, CODENIGHT v1, which is an ACM-ICPC style team programming contest of 2 hours duration to be held on CodeChef during its annual hackathon event [Hack36](https://www.hack36.com). A team can consist of up to 4 members.
**Contest Details:**
- Start Time: [Monday, February 3, 2020, at 21:30 IST](https://www.timeanddate.com/worldclock/fixedtime.html?msg=Codenight+v1+-+CodeChef+Hack36+2020&iso=20200203T2130&p1=2408&ah=2)
- Duration: 2 hours
- Contest Link: [https://www.codechef.com/HK362020](https://www.codechef.com/HK362020)
- The problemset consists of 8 problems.
- Languages allowed: C, C++, Java and Python.
Top 3 global teams will get 300 CodeChef laddus each and few top Indian teams get direct entry to Hack36 to be held at MNNIT Allahabad.
 and enter the battle. Good luck!
[](https://www.youtube.com/watch?v=VjEq7VMNyUI)
This time we also allow you to try the game out by [playing it it the browser](http://russianaicup.ru/play)
[cut]
### What is it?
**Russian AI Cup** — annual Mail.Ru Group IT-oriented competition initiative.
In this championship participants will compete writing an artificial intelligence for the game strategies.
Organized by Mail.Ru Group and Codeforces.
We officially support C++, C#, Java, Kotlin, Python, Ruby, Rust. But, same as previously, we ...
Good news — Russian AI Cup 2018 has started! This competition is being held
seventh time, and, Hello everyone! Good news — Russian AI Cup 2018 has started! This competition
is being
157.
Sharif AIChallenge Hi,
Sharif University of Technology is holding an international AI competition. You may read a short description about it below:
=========
Student Scientific Chapter of computer engineering department at Sharif University of Technology will hold the first international Sharif Artifical Intelligence Challenge on March 2nd and 3rd.
This competition will be held in two phases including an online and an on-site phase in which competitors will compete in teams of three in a game designed by our technical team.
The only pre-requisite to enter this competition is familiarity with programming using C++, Java or python. But obviously, knowledge of algorithmic thinking and artificial intelligence will be a great asset for any of the participating teams. The registration for online competition is free and open from february 1st through to february 8th available at http://aichallenge.sharif.edu .
After finishing the online phase which starts on February 9th and continues untill F...
will run submitted codes and teams with highest scores will make it to on-site
competition. Winners, Hi, Sharif University of Technology is holding an international AI competition.
You may read a
158.
Invitation to TOKI OSN Open Contest 2018 Hi Codeforces community! :D
We're excited to invite you to **TOKI OSN Open Contest 2018** -- an online mirror contest for Indonesia national olympiad in informatics. This national olympiad is one of the stages required for our students to qualify to represent Indonesia in the International Olympiad in Informatics (IOI).
The contest is similar to IOI: 2 competition days (+ 1 trial session), each consisting of 3 IOI-style (partial, subtasked) problems to be solved in 5 hours. The schedule is as follows:
- **Day 0**: [2 July 2018 08:35 — 23:05 UTC](https://www.timeanddate.com/worldclock/fixedtime.html?msg=TOKI+OSN+Open+Contest+2018+Day+0&iso=20180702T1535&p1=575&ah=14&am=30) (trial session)
- **Day 1**: [3 July 2018 02:35 — 23:05 UTC](https://www.timeanddate.com/worldclock/fixedtime.html?msg=TOKI+OSN+Open+Contest+2018+Day+1&iso=20180703T0935&p1=575&ah=20&am=30)
- **Day 2**: [4 July 2018 02:35 — 23:05 UTC](https://www.timeanddate.com/worldclock/fixedtime.html?m...
Olympiad in Informatics (IOI). The contest is similar to IOI: 2 competition
days (+ 1 trial session, All three contests are now available on [TLX (https://tlx.toki.id/competition
)](https://tlx.toki.id
159.
Croatian Open Competition in Informatics (COCI) 2020/2021 - Round #1 Hi everyone!
The 15th season of [COCI](https://hsin.hr/coci/) is starting soon!
If you are not familiar with COCI contest format, we encourage you to read the
[announcement](https://hsin.hr/coci/announcement.html).
The biggest news this season is the new judging system and **full feedback**!
You can access the judging system [here](https://evaluator.hsin.hr/).
There you can also find problems from the previous seasons.
The first round will be held this Saturday, [October 17th at 14:00 UTC](https://www.timeanddate.com/worldclock/fixedtime.html?day=17&month=10&year=2020&hour=14&min=0&sec=0&p1=0).
The round was prepared by [user:Gabrijel,2020-10-15], [user:mkisic,2020-10-15], [user:pavkal5,2020-10-15], [user:satja,2020-10-15], [user:stjepanp,2020-10-15], [user:valkyrie,2020-10-15] and me.
Feel free to discuss the problems in the comment section after the contest ends.
Hope to see you on Saturday!
(We are aware that the round overlaps with Codeforces Raif Round 1, but ...
Croatian Open Competition in Informatics (COCI) 2020/2021 - Round #1, /announcement.html). The biggest news this season is the new judging system and
**full feedback
160.
Codeforces Round #333 — editorial ### Hints:
[div2A](#div2A): Try conversions between bases.
[div2B](#div2B): Solve a simpler version of the problem where $A_{i+1} \neq A_i$ for all $i$.
[div1A](#div1A): What are the shortest paths of the vehicles? what's the shorter of those paths?
[div1B](#div1B): Forget about the ceiling function. Draw points $(i,A[i])$ and lines between them — what's the Lipschitz constant geometrically?
[div1C](#div1C): Some dynamic programming. Definitely not for the exp. score of one person — look at fixed scores instead.
[div1D](#div1D): Compute $dif(v)$ in $O(N)$ (without hashing) and then solve the problem in $O(N^2)$. You need some smart merges.
[div1E](#div1E): Can you solve the problem without events of type 1 or 2? Also, how about solving it offline — as queries on subsets.
### <a name="div2A"></a>Div. 2 A: Two Bases
------------------------------------
It's easy to compare two numbers if the same bas...
or -1 and where it happened); it's easy to update this info when encountering a
new non-zero
Tutorial of Codeforces Round 333 (Div. 1)
Tutorial of Codeforces Round 333 (Div. 2)
161.
Interesting problem I thought of: minimum distance of helicopters I thought of this problem while discussing [problem:343C] with my friend. It's basically the same idea as [problem:343C] but over two dimensions instead of one, so I suggest you read the original problem and its solution first.
**Spoiler Alert:** I briefly talk about the solution to the original problem so don't continue reading if you want to try to solve it for yourself.
Also, it is very possible that the new version of the problem I came up with has already appeared in some form in a competition before. If you are aware of a such problem, Please Link It! Or if you can think of a good solution feel free to share as well! One of the main reasons I'm posting here is because I myself am having trouble coming up with a good solution to this "new" problem.
**Brief description of the original problem**
So in the original problem, you essentially have n hard drive heads that can move left and right and m hard drive tracks that must be read located along a 1-dimensional number line...
Also, it is very possible that the new version of the problem I came up with
has already appeared
162.
Polygon Updates (February 2022) Hello, Codeforces.
In this post, I'll share with you a few recent improvements in Polygon made by [user:MikeMirzayanov,2022-03-03], [user:unreal.eugene,2022-03-03], [user:dk318,2022-03-03] and me.
Polygon is a service to prepares programming problems and contests. It is usually used to prepare problems for olympiads/programming contests but it is also often used to prepare educational content. It is located at https://polygon.codeforces.com/ and is open to everybody.
Here are three recent new features:
* IOI-like Graders for Python
* Problem Materials
* User Groups
[cut]
<br/>
<br/>
IOI-like Graders for Python
==================
About 3 years ago we announced support of IOI graders for C++ in Polygon (Please read [the old post](https://codeforces.com/blog/entry/66916)). Now we have added support for graders written in Python. However, since there is no concept of linkage in Python, Python graders are different from C++ ones.
In the case of Python, the gra...
recent new features: * IOI-like Graders for Python * Problem Materials * User
Groups [cut]
163.
Community Code Cup 3 Hello, Codeforces!
==================
I am pleased to invite you to participate in our new [Community Code Cup 3](https://cups.online/en/contests/contests_code_cup) round that will take place on the **All Cups** platform! The competition will take place [Friday, April 19, 2024, at 17:05]() and will be held according to the **ICPC** rules:
- All solutions will be tested on a **full** set of tests;
- **The penalty** for an incorrect attempt in this round will be $20$ minutes;
- The rating table will be frozen in the **last hour**.
**$6$** — **$7$** interesting tasks are expected for the participants of the competition. The duration of the round will be $2$ hours.
The tasks have been prepared by:
- Ilya Isaev [user:Ilya_Is2022,2024-01-02]
- Stanislav Nekrasov [user:nekstas,2024-01-02]
- Ilya Donov [user:donovilia2007,2024-03-23]
- Maksim Gorshunov [user:maksonchik20,2024-03-23]
The illustrator of the contest:
- Victoria Moskaleva [user:vika1310,20...
Hello, Codeforces! ================== I am pleased to invite you to participate
in ournew, I am pleased to invite you to participate in our new [Community Code Cup
3](https://cups.online/en
164.
New coding competition: Bot Land Bot Land is a competition where you code AI for robots which fight other peoples' robots. I think anybody who loves competitive coding and strategy games will absolutely love it. For the past few weeks I've sank most of my free time into developing strategies and coding bots. Bot Land was released a month ago after effectively being in beta for 4 years.
The game has 2 programming interfaces: a scratch-like interface (for non-programmers) and a subset of JavaScript (for programmers). In addition to coding, you also design your bots (choose weaponry etc.) and you position your bots on the map. The battles are asymmetric: the defender saves their defense and then anyone can attack it (the defender does not have to be online). All battles have 3 rounds, so the attacker can exploit discovered weaknesses of the defender in subsequent rounds. This advantage is mitigated by allowing the defender a higher number of bots, etc. Naturally, there are two leaderboards: one for attacking and one f...
New coding competition: Bot Land, developer, I just enjoy the competition and I would love to see more
competitors!, Bot Land is a competition where you code AI for robots which fight other
peoples' robots. I think
165.
Kotlin Heroes 7 Announcement <img src="/predownloaded/6b/62/6b62332b37519ade4a4d42cb266937c422b64557.png" style="width:500px;float:right;margin:0 1em 1em 1em;"/>
Hello, Codeforces!
First and foremost, we would like to say a massive thank you to everyone who entered and submitted their answers to the five Kotlin Heroes competitions which were held previously: [Episode 1](https://codeforces.com/contests/1170), [Episode 2](https://codeforces.com/contests/1211), [Episode 3](https://codeforces.com/contests/1297), [Episode 4](https://codeforces.com/contests/1346), [Episode 5: ICPC Round](https://codeforces.com/contest/1431), and [Episode 6](https://codeforces.com/contest/1488).
Ready to challenge yourself to do better? The [contest:1533] competition will be hosted on the Codeforces platform on [contest_time:1533]. The contest will last 2 hours 30 minutes and will feature a set of problems from simple ones, designed to be solvable by anyone, to hard ones, to make it interesting for seasoned competitive programme...
better? The [contest:1533] competition will be hosted on the Codeforces
platform on [contest_time:1533
Announcement of Kotlin Heroes: Practice 7
Announcement of Kotlin Heroes: Episode 7
166.
Codeforces Round #416 (Div. 2) (based on MSPU Olympiad 2017) Hello everyone!
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<body>
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<img src="/predownloaded/f4/15/f41572c1d2f36ef70a1d6b4d4c477de4a745f32c.png" align=right hspace=20>
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[27 May, 12:35 MSK](http://timeanddate.com/worldclock/fixedtime.html?day=27&month=5&year=2017&hour=12&min=35&sec=0&p1=166) new codeforces round takes place for participants from the second division. Participants from the first division can participate out of competition. Round consists from 5 problems, and you will be given 2 hours to solve them. **Pay attention on round start time**.
The problems will be almost the same as on Open Olympiad of Mozyr State Pedagogical University, which takes part parallel to the round. The full problem set would be in codeforces gym soon. I am also going to tell you about the Olympiad a bit later.
- The problemsetters are: me (Vladislav Vishnevski), Valery Kameko ([user:Valerich,2017-05-26]) and Yury Shilyaev ([user:hloya_ygrt,2017-05-26]).
- The testers are: Alex Kern...
=12&min=35&sec=0&p1=166) new codeforces round takes place for participants from
the second division
Announcement of Codeforces Round 416 (Div. 2)
167.
Announcement: 3rd Hello Barcelona Programming Bootcamp in collaboration with Moscow Workshops ICPC 
Hello, Codeforces!
We are pleased to announce the [3rd Hello Barcelona Programming Bootcamp in collaboration with Moscow Workshops ICPC](http://in.harbour.space/icpc/acm-icpc-hello-barcelona-bootcamp-autumn-2018/?utm_source=Codeforces), organised by [Harbour.Space University](https://harbour.space/?utm_source=Codeforces) with content provided by [Moscow Workshops ICPC](https://it-edu.mipt.ru/en/about_workshops), in collaboration with [Moscow Institute of Physics and Technology](https://mipt.ru/en/), [ITMO University](http://en.ifmo.ru/en/), [Saint Petersburg State University](http://english.spbu.ru/) and Codeforces!
The boot camp will be held from 26 September to 4 October, 2018 in Barcelona, and hosted at the beautiful and technologically mind-bending Media-TIC building — the Smart Building of Tomorrow.
The world's greatest coac...
international competitions. This is an appropriate introduction for teams and
studentsnew to the world
168.
This year,my way,from gray to yellow ~~~~~
First, congratulations ,to all CF members, the New Year!
~~~~~
~~~~~
Maybe,this blog will be boring for you,but I have a wish to share with you impressions from this year's contests.Everything started slowly,I was only newbie and I didn't see how I can improve my programming skills.Always I spent all time to solve one or two problem on the contests.However I was sure that I will succeed on our country competition,and then BUM!I didn't pass the Regional cometition!I was near the border,but had 10 points less!
~~~~~
~~~~~
After that I started to work harder,I learned some algorithms,I learned some data structures(BIT,Heap,Segment Tree,dsu...) and I had a lot of codeforces competitions where I can get new experience.Also,one important thing in all contests is hacking.On every competition I thought about some special cases and watching other codes.I won points and also I saw some good ways to implement solution.
~~~~~
~~~~~
Now,I know that a long way front...
(BIT,Heap,Segment Tree,dsu...) and I had a lot of codeforces competitions where
I can getnew, ~~~~~ First, congratulations ,to all CF members, the New Year! ~~~~~ ~~~~~
Maybe,this blog
169.
Kotlin Heroes: Episode 9 Results <img src="/predownloaded/f8/d6/f8d626d5d138464363a00237083e0b9bbe09e704.png" style="width:300px;float:right;margin:0 1em 1em 1em;"/>
Hello Codeforces!
We’re absolutely thrilled about the return of the Kotlin Heroes series! Judging by the record-setting number of registrations for [Kotlin Heroes: Episode 9](https://codeforces.com/contests/1910), we’re guessing you’ve missed this series as well.
It's great to see new people just getting started with Kotlin already performing well in competitions. The solutions to all eight previous rounds are available for practice purposes here: [Episode 1](https://codeforces.com/contests/1170,1171), [Episode 2](https://codeforces.com/contests/1211,1212), [Episode 3](https://codeforces.com/contests/1297,1298), [Episode 4](https://codeforces.com/contests/1346,1347), [Episode 5: ICPC Round](https://codeforces.com/contests/1431,1432), [Episode 6](https://codeforces.com/contests/1488,1489), [Episode 7](https://codeforces.com/contests/1533,1532) an...
It's great to see new people just getting started with Kotlin already
performing well in
170.
Codeforces Round #438 by 2nd Hello Barcelona Bootcamp with Sberbank <center>
<img src="/predownloaded/d1/0f/d10f26a5c5ba4fa2a31a0b69edc74c7799474e82.png">
</center>
Hi Codeforces!
The Codeforces Round #438 by Sberbank and Barcelona Bootcamp (Div. 1 + Div. 2 combined) is going to be held on [05 Oct at 9:05 (UTC+2)](https://www.timeanddate.com/worldclock/fixedtime.html?msg=The+Codeforces+Round+%23438+by+Sberbank+and+Barcelona+Bootcamp&iso=20171005T0905&p1=31)! The round will be **rated for everyone**.
This round is organised in collaboration with [2nd Hello Barcelona ACM ICPC Bootcamp 2017](http://in.harbour.space/icpc/acm-icpc-hello-barcelona-bootcamp-autumn-2017/?utm_source=Codeforces) and supported by [Sberbank](http://www.sberbank.com/ru), the biggest commercial and investment bank of Central and Eastern Europe, with over 175 years of history.
150 students from 53 universities, including ITMO, University of New South Wales, St. Petersburg State University, MIPT, Ural Federal University, Tomsk State University, Novosibirsk State Univer...
history. 150 students from 53 universities, including ITMO, University of New
South Wales, St
171.
I Reached GM after 5 years Hello Codeforces! I did it! My main goal for 2022 was to reach red and I succeeded in the last contest of the year by getting +1 delta and going from cursed 2399 to 2400! I was very happy but scared to celebrate because I was worried that my rating would go down to 2399 again after the cheater removal. But now it’s 2401, so I think I’m safe now.
Why am I writing this blog? I'm very excited about this achievement, it means a lot to me and I want to share my happiness with Codeforces. Also people ask me in DM quite often about how I got onto this level or who I am in general, so I think it's time to summarize it all into one blog post.
Oh, wait… You don’t even know me, so why should you keep reading this blog post? Let me introduce myself a little first. I’m a high schooler from a small European country where few people do Codeforces. I love competing in OI and MO, I always did. One day, my father found the Codeforces website and suggested that I should start practicing there. At ...
practicing. I always think about it. How did I solve it? Did I learn something
new? What part of the
172.
Community Code Cup 1 Hello, Codeforces!
==================
Me, [user:Alexfil,2024-01-02] and [user:nekstas,2023-12-25] are pleased to invite you to our new official [Community Code Cup 1](https://cups.online/en/contests/contests_code_cup ) round that will take place on the new platform **IT** championships **All Cups**! The competition will take place [Monday, January 8, 2024, at 17:05]() and will be held in accordance with the slightly modified Codeforces rules:
- All solutions are tested on a full package of tests.
- All decisions that do not receive a "Complete solution" verdict are penalized with 50 points.
- No hacking system.
**$2^3$** interesting tasks were prepared for the participants of the competition. The duration of the competition will be $3$ hours ($180$ minutes).
**The final distribution**:
- **$250$** — **$750$** — **$1250$** — **$1750$** — **$2250$** — **$3250$** — **$3250$** — **$3250$**
The tasks have been prepared by:
- ...
take place on the new platform **IT** championships **All Cups**! The
competition will take place, -25] are pleased to invite you to our new official [Community Code Cup
1](https://cups.online/en
173.
TON Smart Challenge #2 <img alt="TON Foundation" src="https://codeforces.com/predownloaded/62/8f/628f11a5c33c9a826d89e1d53801d4c6141ea2dd.jpg" style="float:right;height: 300px; margin: 10px; max-width:50%;"/>
_Hello, Codeforces!_
_Take a look on excellent news from [TON Foundation](https://ton.org/) about TON Smart Challenge._
_Please note that this contest will not take place on Codeforces. It is about smart-contracts, not traditional algorithmic problems. But in the last similar competition, the competitive programmers were among the winners!_
_I pass the floor to the TON team._
The next edition of the TON Smart Challenge contest for programmers is slated to begin on Aug. 4 with a total prize pool of **16,000 Toncoin**.
TON Foundation developers have carefully reviewed and considered feedback from participants of the first TON Smart Challenge and will make quality-of-life improvements for the upcoming second part of the competition.
The TON Smart Challenge #2 is aimed at developers jus...
-contracts, not traditional algorithmic problems. But in the last similar
competition, the, You can find more details and news on the competition on the [TON
Contests](https://t.me
174.
Community Code Cup 2 Hello, Codeforces!
==================
Me and [user:nekstas,2023-12-25] are pleased to invite you to our new [Community Code Cup 2](https://cups.online/en/contests/contests_code_cup) round that will take place on the **All Cups**! The competition will take place [Wednesday, February 14, 2024, at 17:35]() and will be held in accordance with the slightly modified Codeforces rules:
- All solutions are tested on a full package of tests.
- All decisions that do not receive a "Complete solution" verdict are penalized with 50 points.
- No hacking system.
**$5$** interesting tasks were prepared for the participants of the competition. The duration of the competition will be $2$ hours and $15$ minutes.
**Distribution**:
**500** — **1000** — **(750+750)** — **2000** — **4000**
With the support of the service from **VK** « _Другое Дело_ » Small prizes were provided for the participants of the competition:
- **The absolute champion** of the competitio...
you to our new [Community Code Cup
2](https://cups.online/en/contests/contests_code_cup) round that, Me and [user:nekstas,2023-12-25] are pleased to invite you to our new
[Community Code Cup 2](https
175.
Kotlin Heroes: Episode 4 <img src="/predownloaded/d3/f6/d3f67b5afe94939d82d9358aeb7a0edcf6a8d33f.png" style="width:300px;float:right;margin:0 1em 1em 1em;"/>
Hello, Codeforces!
First and foremost, we would like to say a massive thank you to everyone who entered and submitted their answers to the first, second and third Kotlin Heroes competitions which were held previously.
Congratulations to the top 3 winners:
**Episode 1**
1. [user:Petr,2020-02-26]
1. [user:ecnerwala,2020-02-26]
1. [user:eatmore,2020-02-26]
**Episode 2**
1. [user:tourist,2020-02-26]
1. [user:eatmore,2020-02-26]
1. [user:Benq,2020-02-26]
**Episode 3**
1. [user:Egor,2020-05-23]
1. [user:tourist,2020-05-23]
1. [user:Benq,2020-05-23]
Ready to challenge yourself to do better? The fourth "Kotlin Heroes" competition will be hosted on the Codeforces platform
on [contest_time:1346]. The contest will last 2 hours 30 minutes and will feature a set of problems from simple ones, designed to be solvable by anyone, to hard...
. [user:Benq,2020-05-23] Ready to challenge yourself to do better? The fourth
"Kotlin Heroes"competition
Announcement of Kotlin Heroes: Episode 4
Announcement of Kotlin Heroes: Practice 4
176.
A Beginner Template for Codeforces Problems I have been taking part in coding competitions for a few months now. I still have a lot to learn, but I thought I would share with you a beginner coding template that saves me a lot of time when starting a new problem.
The template is for C++ and based on modern C++ practices.
I have carefully looked at the code that top programmers use and they all follow roughly the same pattern. Also, I am not including all kinds of predefined functions, #define or typedef statements, etc. This is a bare-bones template to get started.
Codeforces problems come in two varieties regarding input: Ones with multiple test cases (usually problems A, B and C for more recent contests) and ones with a single test case (usually from problem D onward, but not always, as well as older contests).
Let's first look at problems with multiple test cases. Here is the template:
~~~~~
#include <bits/stdc++.h>
using namespace std;
using vi = vector<int>;
void solve() {
int n;
cin >> n;
...
starting a new problem.
177.
How to exit CP? How do I stop doing it?
I know I can achieve something if I keep practicing, I have many possibilities. I got everything I have through CP, but what did it cost me?
After every round on Codeforces (and I've written a really great deal of them), I feel like a lowly loser every time. Every time I finish another competition and cry because I hate myself. Every fucking time I make the stupidest marks and there's no cure. hasn't been a cure in 5 years. Every time there are situations along the lines of: I came up with a problem from reading, it's very simple. But while I'm writing it, I make a billion different and every time new mistakes. In every line. It's killing me. I come out of div2 realizing that I should have closed it, and ended up passing d with +4 and my performance is 2000, when I almost never have 2600+ level problems.
If I blow it, I'll spend the rest of my life blaming myself for having so many such great opportunities, I had dreams, I was constantly going for some goa...
finish another competition and cry because I hate myself. Every fucking time I
make the stupidest
178.
CROC Champ 2013 — Round 2 Hello everyone!
Round 2 of [All-Russian Programming Championship CROC-2013](http://codeforces.com/croc2013) will take place today. Round was prepared by [user:sdya,2013-04-22], [user:Seyaua,2013-04-22], [user:Gerald,2013-04-22] and traditionally, problem statements were translated to English by [user:Delinur,2013-04-22].
Good news for people, who didn't qualify to this round — today everyone can participate out the competition. Additionally, round will be rated for both official participants and out of competition participants.
Remind some facts about the official participants:
- All the participants should be 18+ years old
- The championship finals are going to take place on May, 16-17 in Moscow in the CROC office (50 participants)
- The CROC company pays for the accomodation in Moscow during the finals
- For Russian citizens: the travel expenses around Russia will be covered, the transport expenses outside Russia can be covered possibly partially but you need...
the competition. Additionally, round will be rated for both official
participants and out of
Announcement of Croc Champ 2013 - Round 2
Announcement of Codeforces Round 179 (Div. 1)
Announcement of Croc Champ 2013 - Round 2 (Div. 2 Edition)
179.
Moscow Workshops Juniors 2021: first qualifying pre-New Year round! 
We welcome high school students to take part in the programming boot camp **Moscow Workshops Juniors** that will be held on **February 24 – March 5** by Moscow Institute of Physics and Technology. The first qualifying online round (out of 3 or 4) will be open on **December 27 at 12:00** pm UTC+03.
Moscow Workshops Juniors is the unique boot camp where students will be preparing for the **national competitions and international olympiads in informatics**. According to the statistics, 17 graduates of MWJ 2020 took part in the IOI and 11 of them won medals.
Two years ago we started an **English-speaking group** at Moscow Workshops Juniors for students from Armenia, Azerbaijan, Bosnia and Herzegovina, Denmark, India, Italy, Syria, and Turkey. Last year guys from Netherlands and Romania also came to Russia. In total about 170 students participate in the boot camp every year. We would be glad to see everyone ag...
Moscow Workshops Juniors 2021: first qualifying pre-New Year round!
180.
New Math Competition — MathDash Hey!
My friend Daniel and I (former USA Math Olympiad participants) are hosting a **[live math competition](https://mathdash.live)** on [Monday Feb 5 at 7:30 EST (4:30 PST)](https://www.timeanddate.com/worldclock/fixedtime.html?msg=MathDash&iso=20240205T1630&p1=224&ah=1). The level of problem will be similar to the MATHCOUNTS competition ([here's an example](https://www.mathcounts.org/sites/default/files/2023%20Chapter%20Competition%20Sprint%20Round.pdf)).
Would love to see signups, feel free to sign up [directly on the site](https://mathdash.live) or through our [Google Form](https://forms.gle/jVWy9xRABYqL7JvCA). Also, would love to hear suggestions on groups of people whom you think this would be the right difficulty for (i.e. who should I share this with!)
New Math Competition — MathDash, competition](https://mathdash.live)** on [Monday Feb 5 at 7:30 EST (4:30
PST)](https
181.
Invitation to TheForces Round #9 (Fool-Forces) [New Round] [GYM] Hello, Codeforces!!
We are happy to invite you to [**TheForces Round #9 (Fool-Forces)**](https://codeforces.com/contestInvitation/abe0c8c96fabb9419d20e41dfce7a7daafa3397b), which will take place on **[contest_time: 104264]**
**Please don't forget the time. Contest starts soon...**
_This competition is similar to April Fool's Day Contests, As there's an official round on April 1st this year, We decided to hold our round sooner._
You will have **2 hours** to solve **8 problems**.
- Problems were prepared and authored by [user:Parisa_Amiri,2023-03-29] and [user:E404_Not_Found,2023-03-29].
- Would like to thank our testers: [user:Little_Sheep_Yawn,2023-03-16], [user:wuhudsm,2023-03-29], [user:O--O,2023-03-29], [user:Nafis,2023-03-29], [user:sjNxksbzj,2023-03-29], [user:_Prince,2023-03-29].
- Also we want to thank **you** for participating in our round.
**P.S : The problems are not sorted by difficulty, So please do read all the problems, Also the round will be avail...
Invitation to TheForces Round #9 (Fool-Forces) [New Round] [GYM], _This competition is similar to April Fool's Day Contests, As there's an
official round on April, competition is similar to April Fool's Day Contests, As there's an official
round on April 1st this
Announcement of TheForces Round #9 (Fool-Forces)
182.
Codeforces Round #224 (Div. 2) Good day everybody)
Welcome to regular Codeforces round #224 for Div.2 participants, first Div2 Only in new 2014 year:). As always Div.1 participants can take part out of the competition.
The problems were prepared by authors Pavel Kholkin ([user:HolkinPV,2014-01-16]) and Gerald Agapov ([user:Gerald,2014-01-16]). I can't already remember exactly in how many rounds I participate as author, co-author of just active assistant) Traditionally thanks to Michael Mirzayanov ([user:MikeMirzayanov,2014-01-16]) for perfect Codeforces and Polygon systems and Mary Belova ([user:Delinur,2014-01-16]) for translating the problems.
**UPD**: Score distribution will be **dynamic**, but the problems will be in supposed order of increasing complexity. The first dynamic round in this year)
We wish everyone good luck, high rating and excellent mood)
**UPD2**: the contest is over, we hope you enjoy it) the editorial is already [here](http://codeforces.com/blog/entry/10442))
Congratulations t...
Welcome to regular Codeforces round #224 for Div.2 participants, first Div2
Only innew 2014 year
Announcement of Codeforces Round 224 (Div. 2)
183.
Info(1) Cup online mirror usaco style Hello everybody!
I know that I've updated my first blog regarding Info(1) Cup a lot of times and I might already seem annoying. Well, the fact is that the first blog's main point was registering new countries in the competition and introducing it. This new blog is for those that might not have seen my updates regarding the online mirrors:
For about 1 day from now on, you'll be able to take part in any 5-hours frame that you wish in a virtual contest in the exactly same conditions as the official participants had. We find the problems really interesting and we challenge you to solve them all. I'm sure that taking part in this contest should be a positive experience for everyone, so I invite you to participate. The contest is OI like (with partial score based on subtask) and includes an interactive task. You can register and find the link of the contest [here](http://open.info1cup.com/). The [live scoreboard](http://open.info1cup.com:8890/Ranking.html) is on. The live scoreboard ...
competition and introducing it. This new blog is for those that might not have
seen my updates
184.
The Beginner’s Guide to Kaggle How do I even start?
Will I be up against teams of experienced Ph.d researchers?
Is it worth competing if I don't have a realistic chance of winning?
Is this what data science is all about? (If I don't do well on Kaggle, do I have future in data science?)
How can I improve my rank in the future?
Well, if you've ever had any of those questions, you're in the right place.
In this guide, we'll break down everything you need to know about getting started, improving your skills, and enjoying your time on Kaggle.
Kaggle competitions
By nature, competitions (with prize pools) must meet several criteria.
Problems must be difficult. Competitions shouldn't be solvable in a single afternoon. To get the best return on investment, host companies will submit their biggest, hairiest problems.
Solutions must be new. To win the latest competitions, you'll usually need to perform extended research, customize algorithms, train advanced models, etc.
Performance must be relative. Competiti...
must be new. To win the latest competitions, you'll usually need to perform
extended research, problems. Solutions must be new. To win the latest competitions, you'll
usually need to perform extended
185.
Codechef Lockout #1 Hey Everyone,
Codechef is going to start a new youtube series called CodeChef Lockout. Many of you might have already guessed by the name, but it will be an intense and fast-paced coding competition between two top competitive programmers, incorporating an esports kind of feeling in competitive programming.
The first match in this series will be in [**1.5 Hours** (Preshow starts at 6:45 PM IST and the contest starts at 7:00 PM IST)](https://www.timeanddate.com/worldclock/fixedtime.html?msg=Codechef+Lockout+%231&iso=20210724T1845&p1=438&ah=1&am=30), which will be between Kshitij Sodani (Handle : [user:kshitij_sodani,2021-07-24]), a 6-star coder and International grandmaster, with a silver medal in IOI 21 and another 6-star coder and International master, Gaurav Sultane (Handle : [user:gaurav172,2021-07-24]).
This match would be hosted and casted by me and I will try to make it as exciting and enjoyable as I can for all of you :}
Come watch the event here : https://www.youtub...
Codechef is going to start a new youtube series called CodeChef Lockout. Many
of you might have
186.
Kotlin Heroes 5: ICPC Round Announcement <img src="/predownloaded/62/39/62391c8471a7dc4ca0b2f2da3e7903eefd1f3dc0.png" style="width:500px;float:right;margin:0 1em 1em 1em;"/>
Hello, Codeforces!
First and foremost, we would like to say a massive thank you to everyone who entered and submitted their answers to the first, second, third, and fourth Kotlin Heroes competitions which were held previously: [Episode 1](https://codeforces.com/contests/1170), [Episode 2](https://codeforces.com/contests/1211), [Episode 3](https://codeforces.com/contests/1297) and [Episode 4](https://codeforces.com/contests/1346).
Ready to challenge yourself to do better? The [contest:1431] competition will be hosted on the Codeforces platform on [contest_time:1431]. The contest will last 2 hours 30 minutes and will feature a set of problems from simple ones, designed to be solvable by anyone, to hard ones, to make it interesting for seasoned competitive programmers.
**Prizes:**
**Top three winners will get prizes of $512, $256, and $128 re...
yourself to do better? The [contest:1431] competition will be hosted on the
Codeforces platform on
Announcement of Kotlin Heroes 5: ICPC Round
Announcement of Kotlin Heroes 5: ICPC Round (Practice)
187.
Hosting IOI 2022 is already stressful -- I plead everyone not to make us more stressful **Disclaimer: all opinions written in this post are purely personal and not tied with any affiliation, organization, or institutional I am working with, including but not limited to the IOI 2022 organizers.** Several members within IOI 2022 organizers might even try to prevent me from posting this.
Dear IOI Community in Codeforces,
I am writing in Codeforces this time, not in e-mails or IOI 2022 website since I am writing this in personal capacity and should not reflect a formal opinion of the IOI 2022 organizers.
As you all might know, IOI 2022 will be conducted hybrid -- it will be hosted onsite, but we understand that it is impossible for some countries to come to Indonesia due to the [current global pandemic](https://en.wikipedia.org/wiki/COVID-19_pandemic), so these countries are still allowed to officially participate online.
I am going to be very honest and transparent in this post.
This is the first time the IOI has a hybrid setting like this.
This poses huge chal...
visas, accomodations, transports, competition venues and equipments, etc.) and
those who participates
188.
Kotlin Heroes 9 Announcement <img src="/predownloaded/dc/3d/dc3d601ff391e638c1f2b20ec167083978099bbe.png" style="width:500px;float:right;margin:0 1em 1em 1em;"/>
**Given the current circumstances, we have decided to postpone Kotlin Heroes until further notice. Thank you for your understanding.**
Hello, Codeforces!
First and foremost, we would like to say a massive thank you to everyone who entered and submitted their answers to the eight Kotlin Heroes competitions which were held previously: [Episode 1](https://codeforces.com/contests/1170), [Episode 2](https://codeforces.com/contests/1211), [Episode 3](https://codeforces.com/contests/1297), [Episode 4](https://codeforces.com/contests/1346), [Episode 5: ICPC Round](https://codeforces.com/contest/1431), [Episode 6](https://codeforces.com/contest/1488), [Episode 7](https://codeforces.com/contest/1533), and [Episode 8](https://codeforces.com/contest/1571).
Ready to challenge yourself to do better? The [contest:1643] competition will be hosted on the Codef...
). Ready to challenge yourself to do better? The [contest:1643] competition
will be hosted on the
189.
Codeforces Round #143 (Div. 2) Hi to all!)
Codeforces #143 for participants from second division is going to be today. I think, it is not necessary to remind, that coders with rating greater than 1699 will be able to take part out of the competition.
Problems' autors for this event are Kholkin Pavel ([user:HolkinPV,2012-10-07]) and Kuznetsov Nikolay ([user:NALP,2012-10-07]). Kudryashov Igor [user:KudryashovIA,2012-10-07] and Agapov Gerald ([user:Gerald,2012-10-07]) helped in contest's preparation too. Special thanks to creator great resource Codeforces Mike Mirzayanov ([user:MikeMirzayanov,2012-10-07]) and our translator Maria Belova ([user:Delinur,2012-10-07]).
Score distribution will be determine later, monitor for changes).
We wish you enjoy participating this competition and want you to get something new and useful.
**UPD**: Score distribution will be **standart** 500-1000-1500-2000-2500.
**UPD2**: Round is over. Thanks to all for participating. Six first coders solved all 5 problems, congratul...
We wish you enjoy participating this competition and want you to get something
new and useful.
Announcement of Codeforces Round 143 (Div. 2)
190.
Bredor Round Good evening, everyone.
In the course of the quarantine, nature has cleaned up so much that I came back to CF. Hello to those who don't know me, and sorry to others.
I want to introduce a few amendments to the gym section and add my contest there. I originally planned to host it on April 1st, but I was a bit late, so the contest will be half-joke, half-traditional.
You will be given **from 6 to 8 tasks** and **from 2 to 3 hours**. During the contest, you will be provided with the opportunity to help Mike, Rudolph, and some other good people.
The competition will be suitable **for all divisions, genders, and races**.
Of course, I would like to thank [user:MikeMirzayanov,2020-06-25] for CF and Polygon, and also express my condolences to people who agreed to test the problems.
The winner will be awarded a valuable prize — **an online certificate**.
The contest will start on [contest_time:102638], follow the link: [contest link](https://codeforces.com/contests...
opportunity to help Mike, Rudolph, and some other good people. The competition
will be suitable
191.
Proper Form in Competitive Programming Link to blog post in my website: https://mredigonda.github.io/blog/proper-form-in-competitive-programming/
1
I recently started lifting weights and exercising more, I wish I would've done that while I was practicing for [IOI](https://stats.ioinformatics.org/) / [ICPC](https://icpc.global/).
My mind kept telling me that an hour in the gym was an hour I could've spent practicing for competitions, and while that was technically correct, that didn't took into account all of the benefits from exercising, not only to my health but also directly to my performance in competitions.
One important aspect that I think would've benefitted me from exercising more is the analogy of exercise and problem solving. Actually, when practicing for competitive programming competitions, I even call it "training" too.
Not all of the analogies will match perfectly, but I find it interesting to analyze them.
There are the straightforward analogies about challenging yourself. While these are kin...
you learn new things, or improve the confidence on already existing knowledge
/ speed. Something
192.
Kotlin Heroes: Episode 8 Results <img src="/predownloaded/f8/d6/f8d626d5d138464363a00237083e0b9bbe09e704.png" style="width:300px;float:right;margin:0 1em 1em 1em;"/>
Hello Codeforces!
[Kotlin Heroes: Episode 8](https://codeforces.com/contests/1571) was the third round of the Kotlin Heroes series in 2021. The “8” from “Kotlin Heroes: Episode 8” symbolizes our infinite respect for all who participated! We are very happy to see new people learn Kotlin and perform brilliantly in the competition. All the previous rounds are available to be used for practice here: [Episode 1](https://codeforces.com/contests/1170,1171), [Episode 2](https://codeforces.com/contests/1211,1212), [Episode 3](https://codeforces.com/contests/1297,1298), [Episode 4](https://codeforces.com/contests/1346,1347), [Episode 5: ICPC Round](https://codeforces.com/contests/1431,1432), [Episode 6](https://codeforces.com/contests/1488,1489), and [Episode 7](https://codeforces.com/contests/1533,1532).
Сongratulations to the top three contestants:
- ...
all who participated! We are very happy to see new people learn Kotlin and
perform brilliantly in the
193.
Anomalies in the North American ICPC World Finals Selection Hello Codeforces! I am writing this blog post to bring attention to and publicly discuss inconsistencies in the ICPC World Finals selection process for North America.
For those who are unaware, every North American (NA) team competes in one regional (which is usually determined by their geographical location) and top teams are selected from each regional to represent NA in World Finals. The only official rule is that the winner of each region qualifies for finals. The remaining teams are selected based on several criteria that are not officially specified. In the past few years, NA has received 23+ world finals slots.
I am a member of Georgia Tech’s premier ICPC team, and my teammates are [user:AlanWaP,2019-01-25] and [user:RaresC,2019-01-25]. We compete in the southeastern USA (SER) regional in North America. Our region also contains University of Central Florida, who consistently have a top ~25 team at World Finals and who were the North American Champions and bronze medalists...
top teams are not as strong as UCF, one should expect to have closer
competition. - Last, our
194.
Getting ready for ACM-ICPC 2016-2017: weekly trainings on Codeforces <img src="http://worker.codeforces.ru/static/images/icpc/icpc_logo.png" style="float:right;margin:0.5em 1em 1em 1em;"/>
The new season of a collegiate team championship ACM-ICPC is about to start. For example, the registration for the Southern (Saratov) Subregional Contest is already running. I am sure that many participants of the Codeforces rounds will take part in ACM-ICPC this year.
We are launching a series of weekly practice trainings on Codeforces. Naturally, they will be held within Codeforces::Gym. Feel free to participate!
The practice starts on Wednesdays at about 13:10 PM (UTC), which is 16:10 Moscow Time. Expected duration is 4-5 hours. We are going to practice using the problems of different contests of the past years. All you need is common sense and observing these simple rules:
- We will not publish the problem source before the practice starts. We want you to solve the problems on your own in a fair competition. If you use somebody else’s code or cheat in...
:0.5em 1em 1em 1em;"/> The new season of a collegiate team championship
ACM-ICPC is about to start
195.
Ice Vision Challenge Some might have heard about [Vision Hack](http://visionhack.misis.ru/), the competition held by NUST MISiS in September, 2017. This summer we are ready to announce the start of Ice Vision — a new competition on machine vision which is a part of the «Up Great» technological project.
The prize fund of the competition is **2 000 000 rubles**.
The organizers of the competition include the Russian Venture Company and NUST MISiS. ACM MISIS provides a platform ([visiontest.misis.ru](http://visiontest.misis.ru)) for the participants of Ice Vision.
The participants are asked to design an intelligence system for a drone which would allow to recognize road items (such as crossings or road signs) under the conditions of Russian winter.
Teams and individual participants between the ages of 14 and 30 are welcome to apply for participation. In the case of individual participation the missing team members will be assigned on the online-platform.
The qualifying (distant) stage o...
new competition on machine vision which is a part of the «Up Great»
technological project.
196.
Codeforces Round #404. Announcement. Hello, Codeforces!
Tomorrow, in [March 15, 2017 at 18:05 MSK](https://www.timeanddate.com/worldclock/fixedtime.html?msg=Codeforces+Round+%23404+%28Div.+2%29&iso=20170315T1805&p1=166&ah=2) a regular **rated** Codeforces round for participants from the second division will take place. As usual, participants from the first division can take part out of competition. It's my second contest and I hope you'll like it more than my [previous one](http://codeforces.com/contest/734/).
As usual, there will be five problems on the contest and two hours to solve them. I advice you to read all the problems' statements **attentively**. Also check all your solutions for correctness even if they passed all the pretests. Verdict <b><font color="#008000">Pretests passed</font></b> doesn't mean that the solution is completely correct! I wish you to enjoy the contest and learn something new solving the problems.
Like in the last time, the problems will be about Anton and his friends.
Great thank...
, participants from the first division can take part out of competition. It's
my second contest and I
Announcement of Codeforces Round 404 (Div. 2)
197.
Announcement: 1st Hello India x Russia Programming Bootcamp 
Hello, Codeforces!
We are pleased to announce the [**1st Hello India x Russia Programming Bootcamp**](http://in.harbour.space/icpc/acm-icpc-hello-india-bootcamp-spring-2018/?utm_source=Codeforces), with [Amrita School of Engineering](https://www.amrita.edu/campus/amritapuri), [Moscow Institute of Physics and Technology](https://mipt.ru/en/) in collaboration with [Moscow Workshops ACM ICPC](https://it-edu.mipt.ru/en/about_workshops), and of course Codeforces!
The boot camps will be held **from March 22nd to the 30th** in both India and Russia.
We would like to bring your attention to the **new Bootcamp Features:** Hello India x Russia Programming Bootcamp and Moscow Workshops ACM-ICPC will be running both boot camps side by side, every day each camp will be competing in parallel, 7,500 kilometers from each other.
In India and Russia, the Coordinators of the Programming Committee will be both **Gleb**...
and international competitions. This is an appropriate introduction for teams
and studentsnew to the
198.
Codeforces Round #363 Dear friends!
We are glad to invite you to take part in Codeforces Round #363, featuring some problems of the VK Cup 2016 Final Round that took place in Saint Petersburg at the beginning of July. The second part of the problemset will be used to conduct Codeforces Round #364. Of course, we made some new problems to complete the set to fulfill the requirements of the regular round and it now contains problems of the appropriate difficulty for participants of any color.
We will obey the good old tradition to publish the scoring distribution right before the start of the competition.
We wish you good luck and an interesting contest!
**UPD1**. Scoring distribution will be standard in both divisions 500-1000-1500-2000-2500-3000 (yes, there will be six problems featured in both div1 and div2).
**UPD2**. Problems were prepared for you by [user:MikeMirzayanov,2016-07-19], [user:Errichto,2016-07-19], [user:fcspartakm,2016-07-19], [user:qwerty787788,2016-07-19] and [user:Stonefean...
some new problems to complete the set to fulfill the requirements of the
regular round and it now
Announcement of Codeforces Round 363 (Div. 1)
Announcement of Codeforces Round 363 (Div. 2)
199.
Codeforces Round #890 (Div. 2) #####Hi, Codeforces!
[user:Alexdat2000,2023-08-03], [user:Igorfardoc,2023-08-03], and I are pleased to invite you to our [contest:1856], which will be held on [contest_time:1856]. **This round will be rated for participants with a rating lower than 2100.**
We would like to thank:
- [user:errorgorn,2023-08-03] for coordinating the round.
- [user:Yuu,2023-08-03], [user:maomao90,2023-08-03], [user:thenymphsofdelphi,2023-08-03], [user:Dominater069,2023-08-03], [user:Mike4235,2023-08-03], [user:valeriu,2023-08-03], [user:irkstepanov,2023-08-03], [user:zengminghao,2023-08-03], [user:Gheal,2023-08-03], [user:DeMen100ns,2023-08-03], [user:FEDIKUS,2023-08-03], [user:thanhchauns2,2023-08-03], [user:MinaRagy06,2023-08-03], [user:Java,2023-08-03], [user:xudian,2023-08-03], [user:madlogic,2023-08-03], [user:squishybanana04,2023-08-03], [user:stefanbalaz2,2023-08-03], [user:kobebryan9,2023-08-03], [user:Murinh0,2023-08-03], [user:IlyinAD,2023-08-03], [user:Respectively,2023-08-03], [user:p...
:0.5em 1em;">Complete the Form_ __ _We wish you good luck in the competition and
Announcement of Codeforces Round 890 (Div. 2) supported by Constructor Institute
200.
Harbour.Space Scholarship Contest 2023-2024 (Div. 1 + Div. 2) Salam, Codeforces! $\color{white}{\text{ «Be attentive about your thought that becomes your behavior» «Be attentive about your behavior that becomes your speech» «Be attentive about your speech because it becomes your habit»«Be attentive about your habit because it becomes your personality»«Be attentive about your personality because it becomes your destiny» Said by: Imam Ali}}$
We're so excited to invite you to take part in our round [contest:1864] which will start on [contest_time:1864]. The round will be **rated and open for everyone**.
The problems were prepared and authored by [user:amenotiomoi,2023-08-19], Dhruvil [user:Psychotic_D,2023-08-19] Kakadiya, Han [user:wuhudsm,2023-08-19] Jinlong, Amir Hossein [user:Amir_Parsa,2023-08-19] Farhadi, Matthew [user:Chromate00,2023-08-19] Roh, [user:JohnVictor,2023-08-19],
[user:odt,2023-08-19], [user:ugly2333,2023-08-19], [user:lavine,2023-08-19], [user:RiverHamster,2023-08-19],
[user:flowerletter,2023-08-19] and [user:Aquamoon...
by their GPA, professional achievements and official ICPC competition results.
As a guideline, it
Announcement of Harbour.Space Scholarship Contest 2023-2024 (Div. 1 + Div. 2)
201.
Codeforces Round #307 (Div. 2) Hello Codeforces community !
I am glad to announce Codeforces Round 307 (Div. 2) on [12th of June at 19:30 MSK](http://www.timeanddate.com/worldclock/fixedtime.html?day=12&month=6&year=2015&hour=19&min=30&sec=0&p1=166). Authors of this contest are Nikola Mandic ([user:nikola12345,2015-06-11]) and Aleksa Plavsic ([user:allllekssssa,2015-06-11]). This is our first round and we really tried to make interesting and solvable problems. Traditionally Div.1 participants can take part out of the competition ( personally I believe that the problems are worth to Div 1 participants, and nobody can solve everything in 20 minutes ). This is the first Serbian round and we want to invite our friends from Serbia to take part in this round and maybe prepare some of next rounds.
The main character of this round is gonna be GukiZ ( our proffesor of computer science ). He really helps us to become better people and developers !
We want to thank [user:Zlobober,2015-06-11] for help in preparing con...
competition ( personally I believe that the problems are worth to Div 1
participants, and nobody can
Announcement of Codeforces Round 307 (Div. 2)
202.
Facebook Hacker Cup 2021: Qualification Round **The Qualification Round of the 2021 Facebook Hacker Cup is less than 48 hours away!**
The round will begin on [**August 27th, 2021 at 10am PDT**](https://www.timeanddate.com/countdown/generic?iso=20210827T10&p0=224&msg=Hacker+Cup+Qualification+Round&font=slab) and will last for **72 hours (3 days)**. The contest can be found [**here**](https://www.facebook.com/codingcompetitions/hacker-cup/2021/qualification-round).
**Everyone who solves at least one problem correctly will advance to Round 1**, which will take place on September 11th. Please note that all submission judgments will only be revealed after the round ends. More details about rules and other information can be found in the [FAQ](https://www.facebook.com/codingcompetitions/hacker-cup/2021/qualification-round/faq).
Registration will remain open on the contest page until the end of the Qualification Round. Once you've registered, you may wish to confirm that the information in your [competition profile](https://www....
you've registered, you may wish to confirm that the information in your [
competition profile](https
203.
Kotlin Heroes 8 Announcement <img src="/predownloaded/dc/3d/dc3d601ff391e638c1f2b20ec167083978099bbe.png" style="width:500px;float:right;margin:0 1em 1em 1em;"/>
Hello, Codeforces!
First and foremost, we would like to say a massive thank you to everyone who entered and submitted their answers to the seven Kotlin Heroes competitions which were held previously: [Episode 1](https://codeforces.com/contests/1170), [Episode 2](https://codeforces.com/contests/1211), [Episode 3](https://codeforces.com/contests/1297), [Episode 4](https://codeforces.com/contests/1346), [Episode 5: ICPC Round](https://codeforces.com/contest/1431), [Episode 6](https://codeforces.com/contest/1488), and [Episode 7](https://codeforces.com/contest/1533).
Ready to challenge yourself to do better? The [contest:1571] competition will be hosted on the Codeforces platform on [contest_time:1571]. The contest will last 2 hours 30 minutes and will feature a set of problems from simple ones, designed to be solvable by anyone, to hard ones, to mak...
/contest/1533). Ready to challenge yourself to do better? The [contest:1571]
competition will be hosted
Announcement of Kotlin Heroes: Practice 8
Announcement of Kotlin Heroes: Episode 8
204.
Getting ready for ACM-ICPC 2014-2015: weekly trainings on Codeforces <img src="http://worker.codeforces.ru/static/images/icpc/icpc_logo.png" style="float:right;margin:0.5em 1em 1em 1em;"/>
The new season of a collegiate team championship ACM-ICPC is about to start. For example, the registration for the Southern (Saratov) Subregional Contest is already running. I am sure that many participants of the Codeforces rounds will take part in ACM-ICPC this year.
We are launching a series of weekly practice trainings on Codeforces. Naturally, they will be held within Codeforces::Gym. Feel free to participate!
The practice starts on Thursdays at about 12:10 PM (UTC), which is 16:10 Moscow Time. Expected duration is 4-5 hours. We are going to practice using the problems of different contests of the past years. All you need is common sense and observing these simple rules:
- We will not publish the problem source before the practice starts. We want you to solve the problems on your own in a fair competition. If you use somebody else’s code or cheat in ...
:0.5em 1em 1em 1em;"/> The new season of a collegiate team championship
ACM-ICPC is about to start
205.
HackerEarth Hourstorm #8 
Hello!
As the new Contest Coordinator at HackerEarth, I'm honored to invite you to HackerEarth [HourStorm #8](https://www.hackerearth.com/challenge/competitive/hourstorm-8/); it's a 1-hour competition with 3 traditional (but nice) algorithmic tasks. We are going to hold it on Friday at 14:30 GMT (you can check the time [here](https://www.timeanddate.com/worldclock/fixedtime.html?msg=HourStorm%208&iso=20190208T1430&ah=2&am=0).
For traditional algorithmic tasks, you will receive points for every test case your solution passes, so you can get some points with partial solutions as well. Check contest page for more details about in-contest schedule and rules.
[user:AJ_Coder,2019-02-04] is the setter of this round and I'm the tester of problems. Prepared problems were interesting and I enjoyed solving them, I hope you find them interesting too. As usual, here are the prizes f...
As the new Contest Coordinator at HackerEarth, I'm honored to invite you to
HackerEarth [HourStorm
206.
Codeforces Round #158 (Div. 2) Welcome, friends)
New year is coming and meanwhile we are glad to introduce you regular Codeforces round #158 for Div. 2 participants, may be the last in this year). Traditionally Div. 1 participants can take part out of the competition.
Today's problems were prepared by authors: Nikolay Kuznetsov ([user:NALP,2012-12-27]), Fefer Ivan ([user:Fefer_Ivan,2012-12-27]), Pavel Kholkin ([user:HolkinPV,2012-12-27]) and Gerald Agapov ([user:Gerald,2012-12-27]). Traditionally thanks to Michael Mirzayanov ([user:MikeMirzayanov,2012-12-27]) for perfect Codeforces and Polygon systems and Mary Belova ([user:Delinur,2012-12-27]) for translating the problems.
Score distribution will be **standard**.
We wish everyone successful hacks, high rating and happy new year!
**UPD**: the contest is over, we hope you enjoy it)
Сongratulations to winners:
1) [user:ballmaids01,2012-12-27]
2) [user:betalife37,2012-12-27]
3) [user:showtime,2012-12-27]
4) [user:vlyubin,2012-12-27]
5)...
New year is coming and meanwhile we are glad to introduce you regular
Codeforces round #158 for Div
Announcement of Codeforces Round 158 (Div. 2)
207.
Master's thesis about competitive programming? Hi!
Next year I'll start working on my Master's thesis (in computer science), and we have to choose the subjects now. I'm not very enthusiastic about the subjects that are suggested by default but we are allowed to suggest our own topics if we want. So I got an idea: what if I could work on a topic related to competitive programming?
I have good relationships with some of the teachers so I should be able to convince one of them to accept it if it's an interesting subject. But it's not that easy to find a good subject on that theme.
An example I thought of would be to study the current state of the art in a subfield like geometry: which kinds of problems appear in which competitions, which algorithms are considered common knowledge, which kinds of implementations are used, how precision issues are dealt with, etc. I would try to summarize that and to figure out by reviewing the research litterature which new algorithms or techniques might appear in the future, thanks to which i...
to summarize that and to figure out by reviewing the research litterature which
new algorithms or
208.
VisionHack is coming Hello everyone!
MISiS coach team is speaking. This time we want to tell you about an unusual event. This year MISiS together with Cognitive Technologies holds **an international hackathon on Computer Vision and Artificial Intelligence — VisionHack**. It starts very soon — **on July, 21**.
What this hackathon will be about? Which problems will be offered to participants?
Hackathon focuses on designing autonomous cars and developing software for this kind of cars. Participants will be offered a **real-life problem** which occurs in designing autonomous cars. In particular, you will need to identify objects of the road framework (such as road signs and traffic lights) in images or short videos. You will never regret participating in this event as you will spend time solving **exciting problems**, gaining **new knowledge**, improving your coding skills and competing with teams from top-ranking universities. This is indeed not an overstatement — teams from **The...
time solving **exciting problems**, gaining **new knowledge**, improving your
coding skills and
209.
IDAO — International Data Analysis Olympiad 
Hello, Codeforces!
The First [International Data Analysis Olympiad (IDAO)](https://goo.gl/EmSLBg) Began Online This January — Finals To Be Held This April in Moscow, Russia.
This is the best time to join the competition. It will be running until February 11th and the problems will be in English — if you want to take part and win a prize, register now.
[Higher School of Economics](https://www.hse.ru/en/), [Yandex](https://www.yandex.com/) and [Sberbank](http://www.sberbank.com/) along with Harbour.Space University are proud to announce an olympiad created by and for data analysts.
The event aims to bridge the gap between the all-increasing complexity of Machine Learning models and performance bottlenecks of the industry. The participants will strive not only to maximize the quality of their predictions, but also to devise resource-efficient algorithms.
This will be a team machine lear...
competition experts and competitive programming masters, Kaggle winners and ACM
champions, as well as everyone
210.
International Data Analysis Olympiad (IDAO 2020) 
Hello, Codeforces!
[HSE Faculty of Computer Science](https://cs.hse.ru/en/) and [Yandex](https://yandex.com/company/) launch registration for the 3rd International Data Analysis Olympiad ([IDAO 2020](https://idao.world/)). The platinum partner of IDAO 2020 is Qiwi.The Olympiad includes two stages:
**Online Stage (Jan 15 – Feb 11, 2020):**
- Track 1: Traditional machine learning competition on Yandex.Contest platform. You will need to make new predictions and upload them to the automatic verification system.
- Track 2: Come up with a solution for the same problem, keeping within a rigid framework of time and memory used.
**Final (April 2-5, 2020):**
- top 30 teams according to the Online Stage results will be invited to the on-site final, which will be held on April 2-5 in Yandex office, Moscow.
- In the final 36 hours of the competition, participants will try not just to train the model, but...
- Track 1: Traditional machine learning competition on Yandex.Contest platform.
You will need to
211.
Only Div 2 round = BIG PROBLEM Hello CF community!
This blog is my way to draw attention and perhaps start an initiative to solve one big problem on Codeforces.
Before every only div 2 round,CF get hundreds of 'new ingenious users' , and they done all problems, have around 5-6 hacks per round and become candidate masters.That means no opportunity for regular div 2 competitors to jump with rating and feel how to be a winner.Maybe this is unsolved problem , but if we try together to stop this , I belive that we will achieve ceratin results.
Now I will write some of my suggestions , I'd love to read your :)
First:
Div 1 competitions are rarely ,but everybody who prepare tasks for only div 2 contest can ask someone with a high rating to help him around the idea of the most difficult problems.This is certainly reduce only div 2 contest.I think that the best users like [user:tourist,2015-03-01] ,[user:Petr,2015-03-01],[user:WJMZBMR,2015-03-01]... give some advice and help about preparing(Maybe I a...
solve one big problem on Codeforces. Before every only div 2 round,CF get
hundreds of 'new
212.
A transient purple's message to Mike (About Official Participation) TL;DR: Participants who registered while yellow but who dropped to purple must be official participants.
Dear CF community,
Today was supposed to be a great day. After resting from an hour-long leisurely walk around the city, I went to Codeforces to compete in [contest:1934]. Problems A and B went smoothly, as expected. Then, an "Accepted" submission problem C followed suit. As I glanced at the right side panel of the "Problems" page, the minuscule number of solves accompanied by a two-digit count of C-solvers pushed me to continue this winning streak. To my surprise, I got D1. Then D2.
I was convinced that it would be a good day. After a brief saunter for snacks, I returned to my desk and checked the standings, expecting a top 50 finish, which would be my new personal best for a Div. 2 round.
Ranks 1 to 20 loaded onto my screen. "Hmm, was I in the top 20?" I questioned. Nope, not in the first ten nor the first fifteen. My username was nowhere to be found in the official st...
desk and checked the standings, expecting a top 50 finish, which would be my
new personal best for a
213.
Java Pitfalls Recently, I participated in [contest:1828]. I was doing well, and in the last 5 minutes of the contest I solved problem D1, putting me at rank 200 and with CM performance. I was happy with myself until this happened:
I saw that I got TLE on test case 13 and quickly realized what happened. I chose to use Java in this round, and I had somehow fallen in another one of Java's traps. Now, I've decided to compile a comprehensive list of these pitfalls so no one can FST to them again. (Hopefully after you see this you'll be convinced to just use C++.)
**1. Array sorting**
<spoiler summary="Problem">
`Arrays.sort` on an array of primitive types (`int`, `long`, `double`, etc.) can degrade to $O(N^2)$ on adversarial test cases. Note that this does not apply to `Collections.sort` or non-primitive types.
</spoiler>
<spoiler summary="Solution 1">
Apparently, this bug was fixed in Java 14. So on Codeforces...
/wiki/Fisher%E2%80%93Yates_shuffle): ~~~~~ static void shuffle(int[] a) {
Random r =new
214.
About CodeTON Round 1 Prizes <img src="/predownloaded/ce/9f/ce9f87d5c429f47e7691bef3a8934ebf36af3f15.jpg" style="width:250px;float:right;margin:0 1em 1em 1em;"/>
**TLTR:** <i>If you are in the top-1000 of CodeTON Round 1, then fill out the form by the link https://codeforces.com/userForm/203c74605996e40f. Also, anyone who solved at least one problem in the round can fill out it and get 1 TON airdrop. The deadline is 23:59:59 (UTC +3) 04.04.22.</i>
Hello. Great news from the TON Team. I give them the floor.
Good news everyone!
We decided to celebrate the successful finish of the CodeTON round by airdropping all the people who have solved at least one of the problems (officially, practice and virtual participation don't count) of the CodeTON round. Such participants are eligible for 1 TON airdrop and a memorable NFT. Please do note that such NFT bears only symbolic value and is not entered to have any financial or investment value.
Please submit your TON wallet address via the link https://codeforces....
competition here:
215.
How to discover new competitions? I'm sure this has been asked to death but I can't find any great answers. I'm not really sure there are any. I know about [clist.by](https://clist.by/) and a few alternatives (most of the alternatives I've seen seem to list a strict subset of clist's contests though). In particular I'd be interesting in finding out about one-off competitions held by a company or university. Recently there were a few that I only stumbled upon by chance, like the Buckeye Programming Contest or the (admittingly flawed) Credit Suisse competition. Ideally I'd like some way of finding out about these without needing to hear from a friend.
Also I've noticed a pretty frustrating trend of a blog being made on Codeforces that only gets a lot of upvotes and comments by people who just did the competition, so I end up finding out about a competition right after it's over. Is there a good way to filter for contest announcements on Codeforces?
How to discover new competitions?, flawed) Credit Suisse competition. Ideally I'd like some way of finding out
about these without, lot of upvotes and comments by people who just did the competition, so I end
up finding out about a
216.
Terminal — creating AI bot, stream (and $10,000) Hi.
There is a new game where you can win $10k for writing the best bot for a 2-player game Terminal: [https://terminal.c1games.com](https://terminal.c1games.com).
There are some smaller local competitions, mainly for universities.
In short, it's a tower-defense game where you build towers to defend against minions sent by your opponent, and at the same time you attack with minions too.
I have some experience with games like this (we had a few 24-hour game-bot competitions in Poland), so I think I can share some knowledge and intuition. I will stream on Wednesday (1pm CEST), Friday and Sunday. You can see the exact time on my Youtube [channel](https://www.youtube.com/channel/UCBr_Fu6q9iHYQCh13jmpbrg) as a scheduled event. If you miss it, you can watch a video later.
I talked with contest organizers and they encourage the stream, but ofc. you shouldn't expect to hear something enough to get top1.
See you.
Hi. There is a new game where you can win $10k for writing the best bot for a
2-player game, There is a new game where you can win $10k for writing the best bot for a
2-player game Terminal
217.
Codeforces Round #145 (ACM-ICPC Rules) Good day, Codeforces!
I can't wait to give you a good news that a [new competition](http://codeforces.com/contests) for div1 participants is appeared in the list of events. This competition is a broadcast of the Saratov Team Olympiad on Programming and therefore will be held by the ACM-ICPC rules. Especially for div1 participants, we complicate this school competition a bit, so that everyone was interested to solve the problems.
This Competition is individual, it will be rated for both divisions.
Please note that [the start time](http://timeanddate.com/worldclock/fixedtime.html?day=16&month=10&year=2012&hour=11&min=0&sec=0&p1=166) of the competition is different from the usual. Also note the unusual length of the competition.
See you at Codeforces Round #145! I hope that everyone will find the time to participate in the competition.
**UPD. The competition finished, the editorial will come soon.**
Good day, Codeforces! I can't wait to give you a good news that a [new
competition](http, I can't wait to give you a good news that a [new competition
](http://codeforces.com/contests) for
Announcement of Codeforces Round 145 (Div. 2, ACM-ICPC Rules)
Announcement of Codeforces Round 145 (Div. 1, ACM-ICPC Rules)
218.
Hello 2015 Contest Hey everbody.
**Hello 2015** is a Div.1 + Div.2 contest that will be held in gym [soon](http://www.timeanddate.com/worldclock/fixedtime.html?msg=Hello+2015&iso=20150107T19&p1=246&ah=3). As I said, there will be 2 divisions and in each divisions, users of that division can participate ( $(- \infty,1699]$ and $[1700,9999]$). So, anybody who participates in the wrong division will be **out of competition** (manually).
Duration is 3 hours and there will be 6 problems in each division. Last 4 problems of Div.2 will be same as first 4 problems of Div.1 . Problems are written by me ([user:PrinceOfPersia,2015-01-11]) and tester's [user:M.Mahdi,2015-01-11].
The problems will be sorted according to the estimated order of difficulty according to my opinion but I strongly recommend you to read all of the problems.(sentence from [user:matrix,2015-01-11] :D).
Problems ...
competition** (manually). 
219.
APIO 2014 Hello.
APIO 2014 (Asia-Pacific Informatics Olympiad) will take place in 3-4 may 2014 , I wish good luck to all participants.
there is good news, Georgia, Russia, Tajikistan and Turkmenistan have joined APIO starting from this year, which makes getting a medal more challenging :)
Here is a message from APIO 2014 Host committee to our delegation:
> Hello from Kazakhstan!
We are proud to host APIO 2014 and already have some information for you.
First of all, the olympiad will be hosted by one of the best technical universities in Kazakhstan — Kazakh-British Technical University (http://kbtu.kz). Thanks, KBTU!
Secondly, here is the official website: http://olympiads.kz/apio2014 (it's still under construction, but some important information is already available).
Thirdly, the competition date is fixed at May 3-4 (full schedule is available on the website).
And at last, we have 4 new members in this APIO apart from those who joined at IOI 2013. These are: Georgia, Ru...
information is already available). Thirdly, the competition date is fixed at
May 3-4 (full schedule is, ). Thirdly, the competition date is fixed at May 3-4 (full schedule is
available on the website). And at
220.
What will happen to Google Code Jam this year? Since the layoff announcement, the Google Code Jam and Kickstart contest pages have been changed to say that the registration has been delayed. Layoffs are definitely difficult times for everyone and the company, but I just want to say that Google Code Jam is a milestone contest for me each year. I do competitive programming for a hobby (I don't work in a technical role or industry) and I practice regular to do better at subsequent year's Code Jam competitions. I hope everyone will get to share in the excitement of CP by competing in one of the largest contests of each year.
(Hopefully Meta Hacker Cup will continue this year!)
**Update**: Google will be discontinuing all its competitions. This is literally a shock to me as I that they would just suspend for a year or two. While I came on CP only around late 2020 as a new lockdown hobby, I still managed to make some bittersweet memories of competing on Google Code Jam and Kickstart.
I still remember taking part in my first Kic...
that they would just suspend for a year or two. While I came on CP only around
late 2020 as anew
221.
Unofficial list of IOI 2020 participants As in previous years, the list of all the great people who will compete in the most prestigious competition for high school students can be found here: https://kostka.dev/ioi/20/.
If you want to add new participants, please use this form: https://forms.gle/mzzku4dcQXqSD4um8.
If you want to report any mistakes or problems, please either fill the form above with correct data or add a comment under this post.
competition for high school students can be found here:
https://kostka.dev/ioi/20/. If you want to
222.
How much time have you spent solving problems? Hello Codeforces!
Since I have exams in a few days, I was thinking about what I have spent my life on, and why I haven't been preparing for the exams all that time, doing CP instead. So, I decided to calculate a rough amount of time I have spent solving problems.
### **Codeforces**
I have participated in $152$ contests, each being $120$ minutes on average.
I have upsolved $892$ problems. There were a lot of easy problems that I've solved in $10$ or $20$ minutes, and there were some problems I had to think about for more than $5$ hours. Since solving problems also involves coding them, I decided to take the average as $60$ minutes.
Summing up, I have spent $152 * 120 + 892 * 60 = 71760$ minutes or $1196$ hours spent on $152$ contests and $892$ upsolved problems on codeforces platform.
### **atcoder**
I have participated in $28$ atcoder contests, each being $100$ minutes on average.
I have upsolved near to $50$ problems, and as with the case of codeforce...
olympiads, each having $2$ contests. I've participated in $1$ IATI competition
, consisting of $2
223.
New google competitive programming model seems to have a potential rating between Expert and CM Quoting directly from the [technical report](https://storage.googleapis.com/deepmind-media/AlphaCode2/AlphaCode2_Tech_Report.pdf) of Google's new AlphaCode 2 model,
"We found AlphaCode 2 solved 43% of these competition problems, a close to 2× improvement over
the prior record-setting AlphaCode system, which solved 25%. Mapping this to competition rankings,
we estimate that AlphaCode 2 sits at the 85th percentile on average – i.e. it performs better than 85%
of entrants, ranking just between the ‘Expert’ and ‘Candidate Master’ categories on Codeforces"
What do you think it means for the future? If they figure out how to improve it like their alpha go/chess models then we might have something magical in our hands pretty soon
New google competitive programming model seems to have a potential rating
between Expert and CM, "We found AlphaCode 2 solved 43% of these competition problems, a close to 2×
improvement over the, /AlphaCode2/AlphaCode2_Tech_Report.pdf) of Google's new AlphaCode 2 model, "We
found AlphaCode 2 solved 43
224.
You know you are a programming competitions addict when ... Since TopCoder forums are not that active anymore, and I think Codeforces forums are more active, I decided to start (or continue) the [You know your a TopCoder when ...](http://apps.topcoder.com/forums/?module=Thread&threadID=181210) thread here.
It was one of my favorite threads on TopCoder, and I enjoyed reading almost every response.
Let's continue by adding new interesting responses here!
, and I enjoyed reading almost every response. Let's continue by adding new
interesting responses, Let's continue by adding new interesting responses here!
225.
HackerRank HourRank 1 Hello Codeforces community !
I am glad to announce the first HackerRank HourRank round! The contest will be held on [15th October 2015 at 15:00 UTC](https://www.timeanddate.com/worldclock/fixedtime.html?msg=HourRank%201&iso=20151015T1500&ah=1&am=0). You can sign up for the contest [here](https://www.hackerrank.com/hourrank-1). Top 10 winners on the leaderboard will receive a HackerRank T-Shirt.
Problems have been set by Shafaet Ashraf ([user:Shafaet,2015-10-11]) and Aleksa Plavsic ([user:allllekssssa,2015-10-11]). Competitors will have 1 hour for solving 4 problems with variable scoring distribution. Contest are rated for all HackerRank users.
I want to thank whole HackerRank team for support and opportunity to organize the new format of competition. Especially I want to thank [user:Shafaet,2015-10-11], he is really great guy and his help and contributon in contest preparation are incredible. Also I want to thank [user:wanbo,2015-10-11] and [user:svanidz1,2015-10-11] for testi...
I want to thank whole HackerRank team for support and opportunity to organize
thenew format of
226.
5th International Data Analysis Olympiad (IDAO 2022) 
We invite ML students and specialists from all over the world to take part in the **International Data Analysis Olympiad**. HSE University and Yandex are organizing it for the 5th time, and the Otkritie bank will be our platinum partner this year.
Since it’s our first anniversary, we decided to change the format: students and ML specialists are divided into two separate divisions. Only students are able to join the main competition — the Student Division. All others can join the Open Division to participate hors concours (for their own interest).
Traditionally, the first stage’s task will be given by the Laboratory of Methods for Big Data Analysis (LAMBDA, HSE University). It will be about predicting the properties of two-dimensional crystals of various configurations. The task for the Finals will be provided by the Otkritie bank. The Olympiad includes two stages:
**Online Stage (1-28 February 2022):**...
• Track 1: Traditional machine learning competition on Yandex.Contest platform.
You will need to
227.
An efficient way for cheating !! Hi Everyone..
I'm new to codeforces, I have been participating in many contests now, and I noticed a strange thing !!
After the contest some participants gets their submission skipped if their code matches someone else's code. After a few easy investigations (you just filter the submissions on skipped verdict, and VWALA !! you got a list of all the skipped submissions during the current contest) I noticed that some participants do this on purpose.
From my previously mentioned investigation, I noticed that some participants have two accounts, one of them is the original one, and the other one is fake. Now they register themselves from both accounts on the upcoming contest. after that, they start the contest from their original account and participate normally like everyone else. Coming to the end of the contest, and if they haven't done well, they simply sign in from the other account, and submit exactly the same code from it, and let the cheating detection system of codeforces...
Hi Everyone.. I'm new to codeforces, I have been participating in many contests
now, and I
228.
Mistake again ! Guys you made mistake again ! It becomes reality of Codeforces rounds. It is sad...
But this blog is not criticism and I won't blame your work!
I only want to say that I appreciate your effort to prepare rounds and I am always happy when I see new CF contest in calendar. So continue with work! I will be better and more careful in future contests after this mistake and hope same from your side !
At the end I suggest idea for finding one more coordinator — two heads think better than one !
Good luck and hope to see many new competitions !
Good luck and hope to see many new competitions !
229.
A new guide for newcomers in CP (Arabic and English references) If you are new to competitive programming, here's a good guide to follow that will let you master the very basic concepts of programming and math, with more than 200 problems picked carefully and sorted according to their difficulties.
All problems and references are gathered in one place [**HERE**](https://docs.google.com/spreadsheets/d/12XlGl2Nae1NXRDNet_bGQ2HM2O3kq-9FS0Jm2pDwFyg/edit#gid=1683044666).
There exist videos and references on each topic in the sheet (all references are in English, videos are in both Arabic and English).
All references are discussed with C++. Just make a copy from the sheet to start your journey in CP.
This sheet belongs to the [ACM ACPC Club Assiut University](https://www.facebook.com/acmicpc.au/). Our aim is to improve problem solving and programming skills of all students interested in participating in programming competitions or anyone wants to improve his/her algorithmic skills.
Feel free to share this sheet and if you have any feedback...
A new guide for newcomers in CP (Arabic and English references), If you are new to competitive programming, here's a good guide to follow that
will let you master
230.
4th International Data Analysis Olympiad (IDAO 2021) 
Registration for International Data Analysis Olympiad (IDAO 2021) is open now. It’s being organized by [HSE University](https://cs.hse.ru/) and [Yandex](https://yandex.ru/) for the 4th time. [Otkritie bank](https://www.open.ru/en) will be our platinum partner this year. The Olympiad will be convened by leading experts in data analysis and aims to bring together analysts, scientists, professionals, and junior researchers. Participation is free. Winners and prize-winners of IDAO 2021 will receive valuable prizes.
This year the online task is coming again from Physics. The task was given by the [Laboratory of Methods for Big Data Analysis](https://yandex.com/company/) (LAMBDA, HSE University) together with [CYGNO Collaboration](https://web.infn.it/cygnus/cygno/?fbclid=IwAR2ToiNBlI_6hr3o1yeN_TOMHuzO6KjSkJQqiHrJ-HkUNZmKnG6RfXdb_ak) (Italy).
The registration is open till **March 12, 2021**. The Olympiad includes...
- Track 1: Traditional machine learning competition on Yandex.Contest platform.
You will need to
231.
Educational Codeforces Round 149 [Rated for Div. 2] Hello Codeforces!
On [contest_time:1837] [contest:1837] will start.
Series of Educational Rounds continue being held as [Harbour.Space University](https://harbour.space/) initiative! You can read the details about the cooperation between [Harbour.Space University](https://harbour.space/) and Codeforces in the <a href="http://mirror.codeforces.com/blog/entry/51208">blog post</a>.
This round will be **rated for the participants with rating lower than 2100**. It will be held on extended ICPC rules. The penalty for each incorrect submission until the submission with a full solution is 10 minutes. After the end of the contest, you will have 12 hours to hack any solution you want. You will have access to copy any solution and test it locally.
You will be given **6 or 7 problems** and **2 hours** to solve them.
The problems were invented and prepared by Adilbek [user:adedalic,2023-05-24] Dalabaev, Ivan [user:BledDest,2023-05-24] Androsov, Maksim [user:Neon,2023-05-24] Mesche...
proficiency_ - _Medalist in any Programming competition is a plus!_ _Make sure
to apply before
Announcement of Educational Codeforces Round 149 (Rated for Div. 2)
232.
Codeforces Round #374 (Div. 2) Hello, Codeforces!
[30th September 2016 at 17:05 MSK](http://www.timeanddate.com/worldclock/fixedtime.html?day=30&month=9&year=2016&hour=17&min=5&sec=0&p1=166) Codeforces Round #374 (Div. 2) will take place for second division participants. Traditionally, participants from the first division will be able to join out of competition. **Please, notice that the start time is unusual.**
This is my second Codeforces round, I tried to make problems interesting for everyone, so **I recommend to read all problems statements!** I hope that everyone will find something new and interesting. I wish lots of accepted runs and higher rating to all participants.
I want to thank Michael [user:MikeMirzayanov,2016-09-28] Mirzayanov for wonderful platforms Polygon and Codeforces, and for help in preparing the problems, my best friends Danil [user:dans,2016-09-28] Sagunov also for help in preparing the round and Ivan [user:BledDest,2016-09-28] Androsov for testing the problems.
Participants will...
will be able to join out of competition. **Please, notice that the start time
is unusual.** This is
Announcement of Codeforces Round 374 (Div. 2)
233.
Getting ready for ACM-ICPC: weekly trainings on Codeforces <img src="http://worker.codeforces.ru/static/images/icpc/icpc_logo.png" style="float:right;margin:0.5em 1em 1em 1em;"/>
The new season of a collegiate team championship ACM-ICPC is about to start. For example, the registration for the Southern (Saratov) Subregional Contest is already running. I am sure that many participants of the Codeforces rounds will take part in ACM-ICPC this year.
We are launching a series of weekly practice trainings on Codeforces. Naturally, they will be held within Codeforces::Gym. Feel free to participate!
The practice starts at about 12:10 PM (UTC), which is 16:10 Moscow Time. We are going to practice using the problems of different contests of the past years. All you need is common sense and observing these simple rules:
- We will not publish the problem source before the practice starts. We want you to solve the problems on your own in a fair competition. If you use somebody else’s code or cheat in any other way, you will be disqualified. If y...
:0.5em 1em 1em 1em;"/> The new season of a collegiate team championship
ACM-ICPC is about to start
234.
Codeforces command-line interface tool Codeforces Tool is a command-line interface tool for Codeforces.
It's written in golang (without any browser driver). And it's fast, small(only about 7 MB), cross-platform(Windows, macOS, Linux) and powerful.
You can find the source and binary files in my git repo <https://github.com/xalanq/cf-tool>
You can download the tool from release page <https://github.com/xalanq/cf-tool/releases>
Features:
* Support Contests, Gym, Groups and acmsguru.
* Support all programming languages in Codeforces.
* Submit codes.
* Watch submissions' status dynamically.
* Fetch problems' samples.
* Compile and test locally.
* Clone all codes of someone.
* Generate codes from the specified template (including timestamp, author, etc.)
* List problems' stats of one contest.
* Use default web browser to open problems' pages, standings' page, etc.
* Setup a network proxy. Setup a mirror host.
* Colorful CLI.
**UPD:** You can predownload tests as an encrypted zip-archive by the links https://test1.codeforces.com/icpc-challenge-2020-tests.zip or https://test4.codeforces.com/icpc-challenge-2020-tests.zip (~80MB). The password is `64e00d81811bbc463e1e636af`.
Hello everyone!
<a href="https://u.icpc.global/" style="font-size: 15.0px;padding: 8.0px 14.0px;background-color: rgb(207, 56, 34);color: white;">Live broadcast</a>
Announcing the **ICPC Graph Mining Challenge**, Powered by Huawei and brought to you by [ICPC U](https://u.icpc.global/). Graphs are a powerful mechanism for representing many aspects of our daily lives, from mobile call routing to disease tracking. Answering various graph-related questions enables solutions to some of the most challenging, modern problems. The ICPC Challenge prese...
the standard ICPC problems. Previous contests included new programming
languages, multi-agents
Announcement of ICPC Challenge 2020: Practice
Announcement of ICPC Challenge 2020
236.
The D programming language in competitive programming Hi all!
This post is inspired by a question
[here](/blog/entry/51923?#comment-446901) which asks
[user:yosupo,2018-07-28] how using the D progamming language compares to using C++.
I regularly use D where possible in contests (and problemsetting) since 2014,
with some success (for example, a program in D brought me victory in
[AZsPCs: Alphabet City](http://azspcs.com/Contest/AlphabetCity/Standings)).
So I'd like to share my experience.
I'll try to focus on stuff which is important in competitive programming.
The general feeling is as follows.
You can write in D as in plain C when you need full control.
You can also write more like in Python using the powerful standard library.
However, D is a compiled language, so in both cases,
the performance is similar to C++.
Additionally, when the program is written, it is much easier to debug
than a similar program in C++.
For an example, let us look at two solutions of a
[recent problem](/contest/1010/problem/A).
[cut]
...
new paradigms together with the ones already established, which harmed the
overall usability
237.
IATI 2021 Discussion The first day of IATI 2021 has finished about half an hour ago. Please feel free to discuss the competition here!
## Problems
- Day 1: https://drive.google.com/drive/folders/181qblYWJlQjkAUQaMtzxDwJnvh7zUeBO?usp=sharing
- Day 2: https://drive.google.com/drive/folders/18Sd24hOt6VmhdQgaUuak0804lj3bTnM8?usp=sharing
## Results
- Seniors: https://cdn.iati-shu.org/files/standing_A12.pdf
- Juniors: https://cdn.iati-shu.org/files/standing_B12.pdf
## Editorials
- [A11-Heaps](https://codeforces.com/blog/entry/97267#comment-861705) (unofficial)
- A12-Miners
- [A13-News](https://drive.google.com/file/d/1wZAAUh8iQLmG_QCkkTmrMNU2onVuq3Cn/view)
- [A21-Hint](https://codeforces.com/blog/entry/97267?#comment-862120) (unofficial)
- [A22-Delivery](https://codeforces.com/blog/entry/97267?#comment-863025) (unofficial)
- [A23-Rabbit](https://codeforces.com/blog/entry/97267?#comment-862273) (unofficial)
- [B11-Pretty](https://drive.google.com/file/d/1nmCKB7gRG1AUEtnjofIvGeIKM_u...
competition here! ## Problems - Day 1: https://drive.google.com/drive/folders
238.
8th BSUIR Open Programming Championship <div style="text-align: center; margin-bottom: 10px;">
<img src="https://clist.by/static/img/banners/bsuir-open-2018-2.png"/>
</div>
The **8th BSUIR Open Programming Championship** will be held from February 16 till April 13, 2018 (Minsk, Belarus).
[cut]
Undergraduates and postgraduates of BSUIR, students of other educational institutions, students from other universities and countries are invited to participate in the Championship.
The competition will take place in several rounds:
- first qualifying round (distance, problems in Russian) — February 16-19;
- second qualifying round (distance/onsite semi-final, russian and english problems) — February 21;
- **Championship final for students teams (onsite, only english problems) — March 14-16**;
- **Championship final for school teams (onsite) — April 11-13**.
First qualifying round is required only for BSUIR and high school teams but other registered teams can also take part in it. **Second qualifying round is requi...
are invited to participate in the Championship. The competition will take
place in several rounds
239.
How to expand the class of problems in CP without losing objectivity + simplifying organization **Who am I?** I took up ACM ICPC in 2006 as a student, went to the semi-finals 5 times, trained the teams of a provincial university, held several camps for schoolchildren from the zero level and above, and participated in the organization of regional competitions many times (ContestSfedu aka Championship of the South of the Russia aka GP of Azov Sea — Opencup). In recent years, I have been pursuing a career, so I do not actively participate in the sports program, but from time to time I continue to help in holding competitions in Taganrog.
**Why am I speaking out?** More and more often I find myself thinking that competition programming does not keep up with the rapidly changing world and it becomes more difficult to find arguments for students to do it. It's probably easier with schoolchildren, but it's only a matter of time. Do those who organize ICPC, school Olympiads, etc. understand this problem? — I don't know, because I'm not actively involved in the activities o...
often I find myself thinking that competition programming does not keep up
with the rapidly changing
240.
Codeforces Deltix Round Summer 2021 [Div.1 + Div.2] <a href="https://deltix.io/"><img alt="deltix" src="https://assets.codeforces.com/images/deltix/EcCsUtwbu1yq6Av.gif" style="float:right; height: 400px"/></a>
<p>Hi <span style="font-weight:bold">Code</span><span style="color:rgb(71,94,152);font-weight:bold">forces</span>!</p>
We are **[DELTIX](https://deltix.io/)**. Founded in 2005, DELTIX is one of the market leaders in software development for financial research and products for systematic and algorithmic trading. In 2020 DELTIX joined the EPAM family. Our mission is to turn promising ideas into breakthrough products fast.
We are experts in:
* aggregation, storage, and processing large volumes of time-series data
* data modeling
* testing and deployment of quantitative models
In our team we value such skills as:
* knowledge of algorithms
* high-performance coding
* low latency data streams processing
We are excited to announce that one of our products [TimeBase Community Edition](https://github.com/finos/...
. Nevertheless, we take on new challenges in other areas such as IoT, cloud
computing, clustering, high
241.
How to be red: Arpa [user:Arpa,2021-02-28]'s interview:
_-Salam AmirReza_
-Salam Natalia
_-Do you remember becoming red?_
-Yes, exactly one year ago, for the first time, I touched red just with 2405 :))
[cut]
_._
_-Did you celebrate it?_
-For sure, I celebrated it in my mind for several days. But if you mean a real celebration, with others' participation and some sweet, drink and food, no. I was in my hometown at that time, and my little brother and my parents became happy.
_-Was becoming red the most special for you, or getting some other color was more emotional?_
-I remember when I reached Candidate Master. I was 15 at that time. Note that at that time, purple was starting from 1700. That was very nice. But for sure, becoming red was much more emotional.
_-What color was your goal when you started?_
-I rarely had a goal. Becoming red became my goal in 2019. Especially, I never imagined that I could sometime reach IGM. I exactly remember the contest Globa...
~November 2020; what was it?_ -After I married and started my new life,
suddenly everything changed. I
242.
A Codeforces Contest Parser and Sample Tests Generator Many thanks to [user:brunoja,2014-01-19]. He is the main contributor now. Please try it out and give us feedback. You're also welcome to fork the project or join us as a collaborator.
https://github.com/johnathan79717/codeforces-parser
Codeforces Parser v1.4.1
=================
Summary
-------
[Codeforces](http://codeforces.com/) is a website for _competitive programming_. It holds contests, so-called **Codeforces Rounds**, about every week.
This is a python program that parses the sample tests from the contest problem pages. For each problem, it generates the sample input/output files and a shell script to run sample tests.
You can also find this article here, [http://codeforces.com/blog/entry/10416](http://codeforces.com/blog/entry/10416)
### Example:
`./parse.py contest_number (e.g. ./parse.py 464)`
Where `464` is the contest number, not the round number! Check the URL of the contest on your browser, that is the number you are supposed to use.
### Effec...
. Forcing a new line on the input/output if there is none. Fixed some line
number information in this
243.
Design competition for Codeforces T-shirts — results Hi, Codeforces! We summed up the results of design competition for T-shirts :)
Codeforces team looked up all options, sent by community in comments [to this post](http://codeforces.com/blog/entry/57479). After discussion we chose the winner. Congratulations [user:cjquines,2018-02-22] on the victory! As we promised, your prize is three new design T-shirts!
<center><img src="/predownloaded/a3/60/a360604e32553c1c2aafefd118e907c18edd0e55.png"></center>
Also, we want to mention the prize of the jury's sympathies — [user:BudAlNik,2018-02-22] and his joky design. We will send you one T-shirt with this design.
<center><img src="/predownloaded/12/67/1267a74f23f13f9fe012addc04cc2691110ebbf1.png"></center>
I'll write to the winners in private messages soon!
Thank you all for participating. Until next time! :)
**UPD**: Read [an interesting post](http://codeforces.com/blog/entry/57985) about process of creation of design by [user:cjquines,2018-03-11].
Design competition for Codeforces T-shirts — results, -02-22] on the victory! As we promised, your prize is three new design T-shirts!, Hi, Codeforces! We summed up the results of design competition for T-shirts :)
Codeforces team
244.
Free USACO Mock test on Jan 21st Hi everyone,
X-Camp Academy will provide a **free USACO Mock test** on Jan 21st, 4 PM-8 PM pacific time. Open to all, free.
A brief introduction to X-Camp (x-camp.org): A silicon valley based institute focusing on foundation buildup for the majority of students, and competitive programming for students who are passionate about competitions. Systematic curriculum from beginner to master class level. Nearly 20 USACO Platinum division contestants in the past 2 years. 5 students entered US National Camp in the past two years and two current students are among the top 10 from 22/23 Season Dec Platinum Division.
**Some highlights: **
a. Problems arranged by X-Camp Academy teaching research team and catching the newest USACO problem trends.
b. Simulation of a real competition environment. Best preparation for what’s to be expected for the coming USACO contest in late Jan (Jan 27 to Jan 30).
c. Covering Bronze to Platinum levels.
**Registration Link:** https://docs.google...
research team and catching the newest USACO problem trends. b. Simulation of a
realcompetition
245.
Useful links <p class="MsoNormal"><span class="apple-style-span"><b style="mso-bidi-font-weight:
normal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";
color:red;background:white;mso-ansi-language:EN-US">Hi everyone!</span></b></span><span class="apple-converted-space"><b style="mso-bidi-font-weight:normal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:red;background:
white;mso-ansi-language:EN-US"> </span></b></span><span class="apple-style-span"><b style="mso-bidi-font-weight:normal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:red;background:
white;mso-ansi-language:EN-US">Here are the useful links of olympiad
programming.</span></b></span><span class="apple-converted-space"><b style="mso-bidi-font-weight:normal"><span style="font-size:10.0pt;font-family:
"Arial","sans-serif";color:red;background:white;mso-ansi-language:EN-US"> </span></b...
246.
Educational Codeforces Round 85 [Rated for Div. 2] Hello Codeforces!
On [contest_time:1334] [contest:1334] will start.
Series of Educational Rounds continue being held as [Harbour.Space University](https://harbour.space/) initiative! You can read the details about the cooperation between [Harbour.Space University](https://harbour.space/) and Codeforces in the <a href="http://codeforces.com/blog/entry/51208">blog post</a>.
This round will be **rated for the participants with rating lower than 2100**. It will be held on extended ICPC rules. The penalty for each incorrect submission until the submission with a full solution is 10 minutes. After the end of the contest you will have 12 hours to hack any solution you want. You will have access to copy any solution and test it locally.
You will be given **6 or 7 problems** and **2 hours** to solve them.
The problems were invented and prepared by Roman [user:Roms,2020-04-09] Glazov, Adilbek [user:adedalic,2020-04-09] Dalabaev, Vladimir [user:vovuh,2020-04-09] Petrov, Ivan [us...
digital transformation opens the door to some pretty awesome new opportunities
that allow us to get
Announcement of Educational Codeforces Round 85 (Rated for Div. 2)
247.
Innopolis University Informatics Summer Camp <img src="/predownloaded/11/61/11614bb18b37741464389c302c706b96ff349469.png" align="right" width="300px"/>
[Innopolis University](https://university.innopolis.ru/en/) invites school children to have a cool summer at the new Online Informatics Summer Camp in Minecraft
When: July 1–15, 2020<br/>
Where: Online in Minecraft<br/>
Who: 6–10 grade (13–18 years old) school children<br/>
Price: 150 Euro (free for prize winners of [Innopolis Open 2020 in Informatics](//codeforces.com/blog/entry/72119)).
You will get:
- advanced training for international competitions in Informatics and Competitive Programming
- analysis of tasks of international contests, webinars and streams from leading coaches and life hacks from international competition champions
- level 80 Minecraft player
To get 80 lvl **[sign up here](http://2020.olymp.innopolis.ru/minecraft?utm_source=codeforces)**.
The qualification contest will be held this weekend. This is going to be a virtual programming contes...
a cool summer at the new Online Informatics Summer Camp in Minecraft When:
July 1–15, 2020
248.
No out of competition option? Context: I am professional programmer and doing competitions is my hobby. Alas I no longer have the time to put enough time to train appropriately. Still I enjoy doing competitions whenever I can.
Typically my rating ranges in the purple/low orange range. However I find it more enjoyable doing div 2 competitions as typically in div 1 I can do only the first easier problems. I don't care that much about rating, if I had the option I would ignore it altogether. Before we used to have the out of competition option but I don't see it in the recent competitions. I know I could in theory create a new account each time I reach div 1, but wanted to know if there are other options. Also what is the reason to remove "out of competition" for mixed rounds?
No out of competition option?, competition option but I don't see it in the recent competitions. I know I
could in theory create a
249.
Codeforces Round #615 (Div. 3) <almost-copy-pasted-part>
Hello!
[contest:1294] will start at [contest_time:1294]. You will be offered 6 or 7 problems (or 8) with expected difficulties to compose an interesting competition for participants with ratings up to 1600. However, all of you who wish to take part and have rating 1600 or higher, can register for the round unofficially.
The round will be hosted by rules of educational rounds (extended ACM-ICPC). Thus, during the round, solutions will be judged on preliminary tests, and after the round it will be a 12-hour phase of open hacks. I tried to make strong tests — just like you will be upset if many solutions fail after the contest is over.
You will be given 6 or 7 (or 8) problems and 2 hours to solve them.
Note that **the penalty** for the wrong submission in this round (and the following Div. 3 rounds) is **10 minutes**.
[Remember] (/blog/entry/59228) that only the <i>trusted participants of the third division</i> will be included in the ...
competition for participants with ratings up to 1600. However, all of you who
wish to take part and have
Announcement of Codeforces Round 615 (Div. 3)
250.
Topcoder SRM #661 Anti-insomnia Member Editorial There's always a problem to fall asleep after a late night (early morning) match, also drinking coffee during competition doesn't exactly help with that. So, here comes a rough write-up of div1 problems.
#### 250 — MissingLCM
As one can verify easily using prime factorization theorem, the LCM of a set of numbers is $\prod_{p\text{ is prime}} p^{\alpha_p}$, where $\alpha_p$ is the maximal power of $p$ which divides some element of the set. Let us find largest $p^t \leq n$ for every prime $p \leq n$; there should be a number in $[n + 1; m]$ that divides $p^t$ as well. Thus, $m \geq p^t (\lfloor \frac{n}{p^t} \rfloor + 1)$; there is a case when the new number divides some greater power of $p$, but we're fine with that. Find the greatest lower constraint for all $p \leq n$. Use the Eratosphene's sieve to find all the primes. An $O(n)$ solution is possible.
#### 450 — ColorfulLineGraphs
Consider vertices from left to right. How many ways there are to place a new vert...
coffee during competition doesn't exactly help with that. So, here comes a
rough write-up of div1
251.
I Made An Android App That Will Help Competitive Programmers To Keep Themselves Updated With All The Upcoming & Ongoing Coding Contests, Taking Place On Big Coding Platforms [Link To The App](https://play.google.com/store/apps/details?id=com.voidmemories.codeclock)
I’m a 3rd-year university student and I’ve been programming for almost 2 years now. A lot of fellow programmers will agree on the fact that one of the best ways to actually master data structure and algorithm is to take part in as many coding competitions as possible. I used to wake up in the morning and visit all the major coding websites to see if there was a contest today. And since there are so many of them, losing track of a few of the contests wasn’t something new.
So in order to solve this problem, I decided to make an android app that would fetch the contest’s schedule from all the major coding websites and display all of them in a single place. No sooner I made the app, I distributed it to all my friends and they find it extremely useful. So I decided to put the app on the play store for other people to explore and use.
Few pointers on the app:-
* Google calendar integration...
so many of them, losing track of a few of the contests wasn’t something new.
252.
2020 ICPC Graph Mining Challenge: one additional week <img src="/predownloaded/2b/2d/2b2daa03cf569b52a7650513465deed63a775945.png" align="right" style="height: 250px; margin: 10px 30px 20px;" alt="text"/>
UPDATED
Dear participants!
Congratulations on joining the [ICPC 2020 Graph Mining Challenge](https://challenge.icpc.global/) powered by Huawei! All were truly amazed by the participation and quality of the solutions. Congratulations to all of the winners! You will be contacted soon about your prizes.
The competition was so fierce that ICPC U and Huawei have decided to keep the fun going by <u>starting a **new**, one-week challenge</u> with all new prizes. The problem and graphs are the same, so you can build on your previous success. <u>All are encouraged to participate in this challenge.</u> You may only win one prize from the entire ICPC Graph Mining Challenge events (all combined). If you place in multiple challenges, you will be able to pick the prize you prefer.
<center style="margin: 2.5em;"> <a href="https:/...
The competition was so fierce that ICPC U and Huawei have decided to keep the
fun going by
Announcement of ICPC Challenge 2020: Marathon
253.
Invitation to Codechef SnackDown 2016 Pre-Elimination Round A Hello CodeForces Community!
Congratulations to all those who have cleared the [SnackDown 2016 Qualifiers](https://www.codechef.com/SNCKQL16). We hope you are prepared for the Pre-Elimination Rounds. There will be two pre-elimination rounds and 1000+ teams ( *to be precise, the top 1000 teams and teams with number of problems solved equal to 1000th team* ) will be selected from each of the 2 rounds, Pre-Elimination Round A and Pre-Elimination Round B, who will further advance to the SnackDown 2016 Elimination.
The CodeChef [SnackDown 2016 Pre-Elimination Round A](https://www.codechef.com/SNCKPA16) begins tomorrow, [at 9 PM IST, 4th June](http://www.timeanddate.com/worldclock/fixedtime.html?msg=SnackDown+2016+Pre-Elimination+Round+-+A&iso=20160604T21&p1=44).
The problems have been set and tested by [user:Cherrytree,2016-06-03] (Sergey Kulik), [user:Antoniuk,2016-06-03] (Vasya Antoniuk), and me ([user:kevinsogo,2016-06-03], Kevin Charles Atienza). The translations are written by ...
travel in India. However, if any of these 20 teams win the competition, their
travel fare will be
254.
2018 Topcoder Open Round 1A 2018 Topcoder Open Round 1A is scheduled to start at 12:00 UTC -4, April 21, 2018. [Click here](https://www.timeanddate.com/worldclock/fixedtime.html?msg=TCO18+Algorithm+Round+1A&iso=20180421T12&p1=98) to see what time it starts in your area
**Editorials**: https://www.topcoder.com/blog/2018-tco-algorithm-round-1a-editorials/
New to Topcoder and the TCO18? The Algorithm Competition is one of the most fierce and popular tournaments. Battle up against some of the biggest names in coding.
[Learn more here](http://tco18.topcoder.com/algorithm/).
You will be able to register for the Round in the Arena or Applet 4 hours prior to the start of the match. Registration closes 5 minutes before the match begins, so make sure that you are all ready to go.
Here's the full schedule of TCO18 Rounds
Don’t know how to compete in Topcoder SRMs?
Check out [this](https://www.topcoder.com/member-onboarding/comp...
New to Topcoder and the TCO18? The Algorithm Competition is one of the most
fierce and popular
255.
Need help in problems from Team Selection Competition in Serbia I'm preparing for Team Selection Competition and these are some problems that I want to know how to solve. Problems are from previous competitions
<spoiler summary="Problem 1">
Given array with $N<=5*10^5$ elements. Find number of subarrays such that every element in subarray appears even times
</spoiler>
<spoiler summary="Problem 2">
Given $N<=5000$ strings. Find the number of pairs of strings such that after concatenating these strings, new string is palindrome
</spoiler>
<spoiler summary="Problem 3">
Given $A,N,M$ . We perform this operation $N$ times : $A=$($A$+$biggestDigit(A)$)%M . Find $A$ after $N$ operations. $A<M<=10^18$ and $N<=10^18$
Edit: $biggestDigit(A)$ is digit with biggest value, not most significant one
</spoiler>
<spoiler summary="Problem 4">
Given $N*N$ matrix A and $Q<=5*10^5$ queries $N<=1000$.
First query: $1$ $X$ $Y$, find farthest element in matrix such that its value is less than $A[X][Y]$ (Ma...
Need help in problems from Team Selection Competition in Serbia, I'm preparing for Team Selection Competition and these are some problems that I
want to know how to
256.
Euristica '19 Announcement [**Programming Club, IIT Indore**](http://progclub.iiti.ac.in/) is proud to announce 2nd edition of **IIT Indore's** inaugural Programming Fest, [__Euristica '19__](https://euristica.in), sponsored by **Arcesium**. The event was realised thanks to the amazing amounts of effort put in by our team across several weeks.
The domain of events we will be organising spans across Competitive Programming, Application Development, Cyber Security and Machine Learning. Prizes netting ₹300K is up for grabs as well!
The fest kicks off on __Monday, 1st April 2019__, and will continue until __Sunday, 14th April 2019__. We've put lots of love and effort into making the problem statements of every contest, and we hope that you enjoy solving them as much as we enjoyed making them :)
The events are planned as follows:-
- **Divide By Zero 7.0** — Euristica's flagship short prog...
Showcase** — A social coding event to build a new software under the
to-be-announced broad themes
257.
A New Cheating Case. Some weird cheating cases have gone unnoticed lately the example of these two accounts [user:Kamal.Saad,2018-11-25] and [user:Laggay,2018-11-25] these two have been astoundingly lately but the idea is that it's not the same person that owns the account that is entering the competitions and of course he can't be caught cheating because he basically doesn't well how do we know simply because we actually know the guy, take for example these two submissions.
[submission:46083363]
[submission:45078037]
same person two different writing styles to be completely honest i don't know why is he doing it and why would someone help him do that and what does that other guy gain but all i know it's a really shitty thing to do that might disappoint people who are actually working hard and deserve to preform better but are not due to people like these.
A New Cheating Case.
258.
Here's how to keep cool in a contest. Codeforces Global Round 10 had some really good problems which required deep thinking for Div.2 folks. And, to not able to solve some problems in the start itself is demotivating. I have seen many folks, including my friends, just quitting the round if they are stuck at some problem. Many of you would have done that too.
So, I am writing this to share my experience in this contest. Here's what happened:
1. Problem A was easy, just a little thinking would do. Still, that easy problem took 5 mins and I was already behind the race.
2. I solved B a little early, grabbed the pace and came in the competition. I felt this could be my contest.
3. Spent 30 mins on solving C with **3 wrong submissions**. Finally, I did solve it.
4. Spent 70 mins on solving D with **6 wrong submissions**. Finally, solved it.
Now, the question is what went wrong for 6 WAs and why I kept trying D. To answer the first question, I did not go through the cases well. I hurried my decisions, came up wi...
in the competition. I felt this could be my contest. 3. Spent 30 mins on
solving C with **3
259.
How Sirius and nepotism ruined the biggest Russian olympiad Hello, Codeforces!
Yesterday there was an important precedent for the competitive programming: the school stage of the Russian National Olympics in Informatics (I will call it ROI) has completely failed. The testing system could not select the language, it did not test or save submissions during the whole contest, and the organizers had to rewrite the rules right during the Olympiad...
The reason for this is not new to our country — nepotism and incompetence. I was a volunteer at one of the schools where the stage was held, and I can tell you how it all happened.
### The problem with online judges
Previously, the school stage was decentralized: each region came up with its own problems and **selected the testing system that was convenient for it**. Sometimes this caused "screw-ups", sometimes there were complaints about the unequal complexity of the problems, but in general the system worked.
At some point, Moscow experts decided that this would not work, and last...
reason for this is not new to our country — nepotism and incompetence. I was a
volunteer at
260.
Codeforces Round #251 Hi everyone,
Codeforces round #251 for division 2 participants will start at June 4,
Wednesday, [19:30 MSK (usual time)](http://www.timeanddate.com/worldclock/fixedtime.html?day=4&month=6&year=2014&hour=19&min=30&sec=0&p1=166). Traditionally we invite Div.1 participants to take part out of the competition.
The round was prepared by me ([user:praveen123,2014-06-02]). This is my first codeforces round.
I have tried my best to make the problem statements as clear as possible.
I hope that everyone will enjoy the round.
Special thanks to Gerald([user:Gerald,2014-06-02]), for his extensive help in problem ideas
verification, problem testing, without his help the contest would not have
seen the day. English translation is done by me with a lot of help from Gerald Agapov([user:Gerald,2014-06-02]). Problems are translated in Russian by Maria Belova([user:Delinur,2014-06-04]).
Many thanks to Pratik Moona([user:pratikmoona,2014-06-02]), Varun Nitish([user:JuanMata,2014-06-03]) f...
competition. The round was prepared by me ([user:praveen123,2014-06-02]). This
is my first
Announcement of Codeforces Round 251 (Div. 2)
261.
Codeforces: the Results of 2012 Happy New Year!
The New Year is in a two-day distance from us and it's good time to summarize the ending year. In a nutshell, this year's been highly productive for the project. Codeforces has set up large championships, rounds followed one after another, we've launched the Codeforces::Gym project, we've added numerous improvements/fixes/innovations. Here's a short list of our deeds:
<img src="http://assets.codeforces.com/2012/2012-codeforces-google-trends-en.png" style="float:right;margin:0 1em 1em 1em;"/>
- when a user votes for a post/comment, his/her authority is taken into consideration, we've introduced anti-bot and froud-detection heuristics
- the Codeforces::Gym has been opened and has come through many improvements
- the Codeforces Markup, based on Markdown has been introduced, accompanied with special Codeforces tags
- Codeforces helped VK.com to carry out a amplitudinous VK Cup 2012 championship which had around 6000 participants!
- the CROC company has used the...
Happy New Year! The New Year is in a two-day distance from us and it's good
time to summarize
262.
Codeforces::Gym <p> We've made it! Or in any case, we are at least very close to it. </p> <p> On January 19, 2012 at 12:00 we open a sub-project called "Gym". In short, its goal is to enable the Codeforces coders not only to participate in competitions and discuss them, but also to train and coach easily. </p> <p> In fact, despite the wide diversity of online judges in the world, a well thought-out training service system does not exist. So, the expectations from this system are: </p> <ol> <li>Collection of online contests, composed mainly of the past official contests. </li><li> Opportunity to integrate the final standings of past contests in the online contests to be able to train "against" the official participants. </li><li> Opportunity to participate in the training at any time whatsoever, without fear that something breaks down and the server will fall. In short, reliability. </li><li> Opportunity to write virtual contests and to solve the problems in a practice mode. </li...
>
The "New Training" form
263.
ICPC 2023 Online Spring Challenge powered by Huawei <img src="/predownloaded/af/22/af228fee1abb015217d8c524de74898aeff36419.png" align="right" style="height: 280px;" alt="text"/>
Hello, Codeforces!
**UPD:** Challenge is over. You can find results [in this post](https://codeforces.com/blog/entry/115695)
We are happy to invite you to an exciting online event: ICPC 2023 Online Spring Challenge powered by Huawei, which will start on [April 13, 2023, 11:00 UTC](https://www.timeanddate.com/worldclock/fixedtime.html?msg=ICPC+2023+Online+Spring+Challenge+powered+by+Huawei&iso=20230413T11&p1=1440).
In this Challenge, you will have a unique chance:
- to compete during 14 days online challenge
- to solve 1 exciting problem prepared by Huawei
- to win amazing prizes from Huawei!
As a special prize, Huawei together with ICPC Foundation will provide the travel trip to the 46th Annual ICPC World Finals in a guest role!
Everyone is welcome to participate. It is an individual competition.
**ICPC 2023 Online Spring Challenge p...
is welcome to participate. It is an individual competition. **ICPC 2023 Online
Spring Challenge
Announcement of ICPC 2023 Online Spring Challenge powered by Huawei
264.
<s>Quantum</s> Google Hash Code 2018 recap stream Sadly, after spending a few hours learning about quantum programming, I decided to cancel the stream.
Maybe I would be able to solve some problems in the warm-up round, but certainly, I don't have enough knowledge to make a stream about it, and I'm afraid I would say something incorrect multiple times and thus cause damage to viewers. I'm extremely sorry for that.
Instead, I will talk about the Google Hash Code competition.
I competed last year with a success.
Our team won the qualification round and we were 6-th in the final round (I hope I remember that correctly because I can't find the standings).
I'm going to go through the problems from that 2018 edition, talk about my codes, and I will give general advice for the contest.
If you want to participate this year, you must hurry — the registration closes tomorrow (on Monday)!
Registration [link](https://codingcompetitions.withgoogle.com/).
The stream starts at [12:00 CET](https://www.timeanddate.com/worldclock/fixed...
the Google Hash Code competition. I competed last year with a success. Our
team won the
265.
Balkan Olympiad in Informatics — Day 2 The second day of the Balkan Olympiad in Informatics has finished and the competition went pretty smoothly, there was a minor bug in the tests of the second problem, but it was fixed quickly.
[Final results](http://www.boi2015.uni-ruse.bg/competition/results)
The tasks in the second day were, in my opinion, more interesting than the first day. Once again here's a link with the problems (from both days):
[Tasks](http://www.boi2015.uni-ruse.bg/competition/tasks)
**Clarkson**
This problem was quite interesting and the solution was based on a suffix structure. Both suffix array and suffix tree were good enough to solve the problem, and building them for O(N log N) or perhaps even O(N log^2 N) was sufficient. The structure was used so you can calculate the function:
F[i] — the largest substring in the first string, starting at index i, that is present in the second string.
After this function was computed, binary search for the answer combined with dynamic program...
The second day of the Balkan Olympiad in Informatics has finished and the
competition went pretty
266.
Iranian Combinatorics Olympiad Hello everyone,
I am very proud to announce that the second Iranian Combinatorics Olympiad is going to be held soon,
also, I will publish the official poster and text for more information.
**Official text:**
Have you ever thought about how scientists are improving artificial intelligence? How do banks predict whether a start-up will be successful or not? Or even how these new navigators can find the fastest way to your destination in a crowded city?
Lots of you might think of mathematics. Well, that's right; but if look more closely, the basic idea for these achievements is Combinatorics.
Combinatorics is one of the main areas in mathematics which is widely used for solving problems in the real world. By solving combinatorics tasks, you can improve your logic and proving skills.
Interested in combinatorics?
We have a very good news for you! Try yourself with some high-quality problems and have a lot of fun by participating in IranianCombinatorics Olympiad.
Iranian Com...
do banks predict whether a start-up will be successful or not? Or even how
thesenew navigators can
267.
Some innovations at Codeforces <div class="from-renderer"><div class="from-renderer">
<div class="from-renderer">
<div class="from-renderer">
<div class="from-renderer">
<div class="from-renderer">
<div class="from-renderer">
<p class="MsoNormal">I will briefly enumerate the changes at Codeforces:<br></p>
<ul style="margin-top: 0.0cm;">
<li class="MsoNormal" style="">
<span style="">Codeforces beta Round #1 is
announced. It will go according to the
ACM-ICPC rules, but will last for 2
hours. You shouldn't expect much from
the problems - in the first place it is organized
to check the system function and your feedback. The
problems will be in two language: Russian and
English. If I finish all the preparatory work
earlier, I'll brin...
similar to that at TopCoder. If the beta-competition goes without system
failures
268.
2021-2022 ICPC, NERC, Northern Eurasia Onsite (Unrated, Online Mirror, ICPC Rules, Teams Preferred) Hello.
In the meantime, the onsite event has already begun. You can follow the results at the link https://nerc.itmo.ru/archive/2021/standings.html (refrain from viewing if you want to plan to write a mirror and want the conditions as close as possible to the participants in the competition).
There is great news. This year it was possible to get together without any online participation. Teams write from one computer! Good old ICPC.
And I suggest you join the online mirror. It is designed for team participation by those who have passed the qualifying competitions. Ready to try? Use the link: [contest:1666].
Good luck!
write a mirror and want the conditions as close as possible to the
participants in thecompetition
269.
CodeChef strike chrome extension Hello coders,
probably some of you know [CodeChef](http://www.codechef.com/) (another programming contest page).
Why am I writing about another page? Because I believe, that when you want to make your rating higher, you have to compete in contests. Some coders think, that practice and contest are the same (just solving the problems), but definitely they are not for me. In contest I'm under the pressure (time pressure, fear, that if I do not solve the problem my rating will be lower, ...) and so I'm doing a lot of mistakes in real contest (like not reading statement carefully, missing some conditions, trying to submit quickly without precise testing and so on).
[cut]
That's why I want to share with you, that on CodeChef page there are long contests. For me it's something in the middle between practice (no competition, no fun) and competition, because you are not under the time pressure.
But real reason, why I'm writing about CodeChef long contests is, that I worte extensi...
middle between practice (no competition, no fun) and competition, because you
are not under the
270.
Codeforces Round 496 (Div. 3) Hello!
This time decided to fill myself in the shoes of the problem writers.
It is very exciting! My challenge was to prepare a round in one day.
It's really incredible pleasure to surrender to my passion and all day
just work on problems!
Despite the fact that in total I've wrote 8 problems, I made it in time.
Initially, I prepared 7 problems, but two of them were found to be used before (thank you,
[user:300iq,2018-07-09] and [user:_kun_,2018-07-09] for poining it) and I removed them and
wrote a new problem.
[contest:1005] will start on [contest_time:1005]. You will be offered
6 problems with expected difficulties to compose an interesting competition
for participants with ratings up to 1600. Probably, participants from
the Div. 1 not be at all interested by this problems.
And for 1600-1899 the problems will be quite easy.
However, all of you who wish to take part and have rating
1600 or higher, can register for the round unofficially.
The round will be hosted...
them and wrote a new problem. [contest:1005] will start on
[contest_time:1005]. You will be
271.
Codeforces Beta Round #99 <p>Hello.<br /><br />Today round is prepared by me. My name is Mikhail Tikhomirov, i am fourth grade student at mech.-math. dep. of MSU, also i work as developer-researcher at Yandex.<br /><br />I want to thank Artem Rakhov ([[user:RAD,2011-12-24]]) for valuable help and thoughtful coordination, Maria Belova ([[user:Delinur,2011-12-24]]) for great-as-always translating statements into English, and also[[user:MikeMirzayanov,2011-12-24]] for letting us all get together today. =)</p><p>Round will be for both divisions. Every division will have five problems as usual, some of them will be the same, some will be not.</p><p>Score distribution:</p><p><b>Div1: 500-1000-2000-2000-2500.</b></p><p><b>Div2: 500-1000-1500-2000-3000.<br /></b></p><p>Today round is the last round in 2011. I want to thank Codeforces team, everyone who invented, prepared or helped in preparing problems this or past years, and those, who help developing the project. Codeforces now is not just a platform for programming ...
best.
Happy new year! =)
UPD:
Round finished. Thanks everybody! Hope you
Announcement of Codeforces Beta Round 99 (Div. 1)
Announcement of Codeforces Beta Round 99 (Div. 2)
272.
Mirror of the first stage of the National Computer Science Olympiad 2022-2023 Hello, Codeforces!
Congratulations to the 22 on the start of the new olympiad season! I wish your olympiad season a good one. I especially wish success to 11th graders, who will have to choose universities and apply for them this year.
I would like to invite you to participate in the mirror phase 1 of the National Olympiad in Informatics. The mirror will be held on codeforces.
This competition will be interesting rather for weaker participants (grey — turquoise on codeforces). The contest should not be difficult for experienced competitors.
The [contest_time:392106] will take place at [contest:392106].
- The competition is by IOI standards (partial points, test groups). You will be given 4 tasks for 5 hours
- **Unrated round**
- Use of any material published before the round is permitted.
Tasks together with me were proofread for errors and tested by [user:Irsanik,2022-10-04], [user:xyz.,2022-10-04], [user:I_love_my_Nadysha,2022-10-04], [user:ma_sad,2022-...
Hello, Codeforces! Congratulations to the 22 on the start of the new olympiad
season! I wish
273.
MAPS 2020 You are invited to participate in MAPS 2020 (Mount Allison Programming Showdown 2020) on [Saturday March 28th 16:00 UTC](https://www.timeanddate.com/worldclock/fixedtime.html?msg=MAPS+2020&iso=20200328T16&p1=1440&ah=5). MAPS is an open, online, ICPC-style programming competition hosted on Kattis. The following site contains all of the relevant information about the contest:
[https://mapscontest.com/](https://mapscontest.com).
It is a 5 hour competition with 11-12 problems. The MAPS problem set has been put together so that it will (hopefully) both challenge reasonably strong teams and be accessible to newer competitors. The difficulty range of the problem set is expected to be similar to that of the North American Qualifier, if you are familiar with that contest. We hope that you will participate!
Registration is available at [https://maps20.kattis.com/](https://maps20.kattis.com).
**EDIT:** Feel free to discuss the problems here after the contest is over!
**UPDATE:** The pr...
It is a 5 hour competition with 11-12 problems. The MAPS problem set has been
put together so that
274.
Invitation to FIICode Contest Hello everyone,
I would like to announce a new (to international competitors) contest: [FIICode](http://fiicode.asii.ro)
[FII Code](http://fiicode.asii.ro) is a contest organized by the Computer Science Students' Association in Iași, together with the Faculty of Computer Science in Iași.
This we hold the 4th edition of the competition, and it is the first time we host the contest on [CSAcademy](http://csacademy.com), and also make it public to international competitors.
[The first round](https://csacademy.com/contest/fii-code-2019-round-1) will be in two days, on 20th Feb.
The algorithmic section of the contest is composed of 3 online rounds, from which we will select the finalists: the first 5 international competitors, and the first 25 romanian and moldavian competitiors will qualify for the onsite final.
The Final will be held in Iasi (Romania) in 12-14 April.
You can find more details on the [competition site](https://fiicode.asii.ro/algoritmica) or on the [fa...
Hello everyone, I would like to announce a new (to international competitors)
contest: [FIICode
275.
Codeforces Beta Round #27 (Codeforces format, Див. 2) <div><div>We want to congratulate you with a happy new school year with this contest. We wish you excellent marks, easy exams and many Accepted in the contests. Let this year bring you many new and interesting knowledge!</div><div><br></div><div>Artem Rakhov and Codeforces team </div><div><br></div><div>P. S. Note that the round will be held on the <a href="http://codeforces.com/blog/entry/456">Codeforces Format Rules</a>. Read the rules before the competition. Good luck!</div></div><div><br></div><div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; font-family: verdana, arial, sans-serif; font-size: 12px; line-height: 20px; "><b>UPD: </b></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; font-family: verdana, arial, sans-serif; font-si...
We want to congratulate you with a happy new school year with this contest. We
wish you
Announcement of Codeforces Beta Round 27 (Codeforces format, Div. 2)
276.
Euristica '18 Announcement [**Programming Club, IIT Indore**](https://pclubiiti.github.io) is proud to announce **IIT Indore's** inaugural Programming Fest, [__Euristica '18__](https://euristica.in), sponsored by **Arcesium**. The event was realised thanks to the amazing amounts of effort put in by our team across several weeks.
The domain of events we will be organising spans across Competitive Programming, Application Development, Cyber Security and Machine Learning. Prizes netting ₹300K is up for grabs as well!
The fest kicks off on __Friday, 23rd March 2018__, and will continue until __Sunday, 8th April 2018__. We've put lots of love and effort into making the problem statements of every contest, and we hope that you enjoy solving them as much as we enjoyed making them :)
The events are planned as follows:-
- **Divide By Zero 6.0** — Euristica's flagship short programming contest
- **Hackathon** &mda...
** — A social coding event to build a new software under the to-be-announced
broad themes. Each
Codeforces (c) Copyright 2010-2024 Mike Mirzayanov
The only programming contests Web 2.0 platform
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