kostka's blog

By kostka, 7 days ago, In English,

Hey Codeforces community,

have you ever seen any problems that use Wavelet Tree/Matrix or can be solved using these data structures?

Problems created especially for these structures don't count (for example they should appear in some competition).

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By kostka, 7 weeks ago, In English,

I haven't seen any post, so let me announce that the Round E of Google Kick Start 2019 is happening this Sunday (August 25) at 5:00UTC. Get ready and register now at g.co/kickstart.

 .

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By kostka, 2 months ago, In English,

During the downtime I realized that there's no other place to chat about sports programming and that's quite bad.

I also want to confess that I'm probably addicted to Codeforces.

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By kostka, 2 months ago, In English,

I noticed that in recent years, a lot of "pass any coding interview"-ads started appearing out of nowhere (or maybe I live under a rock). On the other hand, I worked in many places and talk to many people and no one ever mentioned participating in such courses/bootcamps before. Therefore, I would like to ask if you know any successful stories, where a person went to some programming bootcamp without any prior experience and then started working in some well-known IT company?

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By kostka, history, 3 months ago, In English,

What is this? Some kind of a cipher? A hint for the upcoming round? Is Mike trying to communicate something to us?

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By kostka, 5 months ago, In English,

We probably all noticed that the rating inflation still occurs [citation needed].

In several games, there's a thing called "rating decay", when your rating decreases when you don't play ranked games (in our world: if you don't participate in contests). Please compare:

What do you think about implementing such a solution to the Codeforces rating? It should slowly drain some of the unnecessary rating (especially from people who do not participate anymore). Similar to many sources above, I think it should affect only highly rated users (maybe with 2100+ rating?). It can also serve as an encouragement to participate in contests more often.

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By kostka, 5 months ago, In English,

Hey Codeforces,

summer is coming, so can we try to compile a list of participants of the IOI 2019?

The list can be found here: http://weaselcrow.com/pro/cf/ioi/19/

How to add or update data? Please fill the following form: https://forms.gle/ttDuP3SR7b8pqhxU6

Please note that the data is moderated, so it might take some time for your input to be visible.

Last year's post can be found here: https://codeforces.com/blog/entry/58939

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By kostka, 6 months ago, In English,

If you didn't participate today in Codeforces, Atcoder, Codechef, and TopCoder rounds, can you even call yourself a real competitive programmer?

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By kostka, 7 months ago, In English,

It's almost here! KickStart rounds kick off this Sunday, March 24 with Round A at 4:00UTC. Get ready and register now at g.co/kickstart.

 .

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By kostka, history, 7 months ago, In English,

The wait is over! Join us in our sweet sixteenth year for another CodeJam season of coding excellence. Register now at g.co/codejam.

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By kostka, 8 months ago, In English,

Interested in growing your coding skills?

Kick start is a global coding competition offering programmers of all skill levels the chance to develop and hone their programming skills. Participate in one of our eight online rounds — or join them all!

Here’s how to join us

Register today!

Register before our upcoming practice round on February 23rd then check out the full schedule and add rounds to your calendar so you don’t miss out!

Practice makes perfect.

Get ready for an upcoming round by trying your hand past problems. Also check out our updated FAQ as we’ve made some changes that we think you're going to like!

Join the conversation.

Join our Facebook Group to connect with other participants, chat about problems post-round, and be a part of our community.

What are you waiting for?

Questions? Reach out to kickstart@google.com.

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By kostka, 10 months ago, In English,

Today the Central European Regional Contest took place in Prague, Czechia.

And are you serious? One of the hardest regionals and:

  • there were two breaks when we couldn't touch computers (one lasting about half an hour),
  • contest lasted over 6 hours,
  • they changed the duration of the contest several times (in particular the end changed from 3:50pm to 3:30pm),
  • the workstations were so slow that our programs compiled sometimes over 5 minutes, with an average somewhere near one minute,
  • some teams had to reboot the workstations several times.

I have been to several contests before and I understand that organizing such contest might be hard, but I really think that this contest crossed several lines. One of the most traumatic experiences in my life.

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By kostka, 11 months ago, In English,

Hello Codeforces,

as promised, tasks from the last year Polish Olympiad in Informatics are finally translated:

https://szkopul.edu.pl/p/default/problemset_eng/oi/25

Please ignore Polish titles, if you set the language to English (top right corner), you should see English statements.

I also want to recommend some problems, which (in my opinion) deserve some attention. I won't say why, because I don't want to spoil them, but if you have some spare time, please check out the following problems:

We are aware that the translations are not flawless, please let us know if we've made some mistakes.

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By kostka, 12 months ago, In English,

Hey Codeforces!

I made a thing and I want to share it with the community.

We wanted to keep track of achievements and submissions in our team and using Codeforces status page is not really handy. Therefore, I introduce to you Team dashboard.

Here you can find some kind of a timeline for each member of your team, showing last submissions, contests and even blog posts on Codeforces.

Using this script is pretty easy, just specify up to 3 handles in the address, separated by semicolons (please check below). Also please keep in mind that this script was made in 3-4 hours, so there is almost certainly a handful of bugs. Also, the script asks a lot of queries to the Codeforces API, so sometimes not all requests are answered. You should wait a couple of seconds and try again.

Visit right now and bookmark your team:

http://weaselcrow.com/pro/cf/team/?h=Radewoosh;Errichto;kostka

You can also compare yourself with your archenemy:

http://weaselcrow.com/pro/cf/team/?h=kostka;olekluka

Upd: fixed some bugs, including incorrect places and no response if no one from the team submitted anything.

Upd2: fixed bug with blocked blogs.

Upd3: you can now request as many days as you want, adding d argument, for instance:

http://weaselcrow.com/pro/cf/team/?h=mnbvmar&d=60

Please use it carefully, as requesting too many days will probably timeout.

Upd4: added team rating, as calculated by Codeforces.

Upd5: added problem ratings.

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By kostka, 13 months ago, In English,

Do you need even more Polish problems in your life? This year we are going to organize some contests on our educational platform (Szkopuł) and we decided to open them to the public. All contests will consist of problems from the previous editions of the POI, so you might be quite familiar with them if you ever solved problems on Szkopuł or on MAIN.

First contests (four of them) will imitate the first stage of the POI. Each contest will consist of three problems, last a week (start at 00:00 CEST on Monday, end at 23:59 CEST on Sunday) and have no feedback during the contest (but you have plenty of time to test your submissions). The first contest will start on September the 10th.

How to register? Just create an account on Szkopuł (https://szkopul.edu.pl/) and click on this invitational link: https://szkopul.edu.pl/c/tren18/join/RMQAKCjHhr1ceqVxywNIU5Kv/

Enjoy!

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By kostka, 13 months ago, In English,

Shoutout to Benq, who in the really awkward interview at the IOI closing ceremony thank Codeforces for its contests!

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By kostka, 14 months ago, In English,

CEOI 2018 is now a part of history!

Task statements, test data, model solutions, translations and some slides with solutions can be found at https://ceoi2018.pl/tasks/

We have two winners of CEOI 2018: Costin-Andrei geniucos Oncescu from Romania and Mariusz Mariusz1 Trela from Poland. Congratulations! Full scoreboard can be found at https://ceoi2018.pl/results/

The problems were added on Szkopuł and can be solved there (unfortunately, right now only in C/C++): https://szkopul.edu.pl/p/default/problemset_eng/ceoi/2018

We uploaded some photos to our Facebook fanpage: http://fb.com/ceoi2018

And finally, CEOI 2019 will take place in Bratislava, Slovakia!

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By kostka, 14 months ago, In English,

The Central European Olympiad in Informatics (CEOI) is an annual informatics competition for secondary school students for central European countries. The 25th CEOI takes place in Warsaw, the capital of Poland.

This year, 13 countries will participate in the CEOI: Austria, Azerbaijan, Croatia, Czechia, Georgia, Germany, Hungary, Italy, Romania, Slovakia, Slovenia, Switzerland, and Poland. The full list of participants is available at: https://ceoi2018.pl/teams/

There will be two competition days: 8/14 and 8/16 (Tuesday and Thursday). We invite everyone to participate in the online mirror, hosted by the CS Academy (details). The contest will start both days one hour after the end of the onsite competition (at 13:00 UTC) and last 5 hours (till 18:00 UTC).

Further info can be found on the official website of the competition: https://ceoi2018.pl/ and our Facebook fanpage: https://facebook.com/ceoi2018/.

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By kostka, 14 months ago, In English,

You asked for it and we are trying to deliver! Almost all tasks from the 22nd, 23rd and 24th Polish Olympiad in Informatics are already translated and are available on Szkopuł:

Tasks from the last edition (25th) are being translated.

Please don't be scared of Polish titles, that's because we are trying to unify all problems. The problem statements should be in English. In particular, check if your language is set to English (the flag in the upper-right corner).

Out of all 396 original tasks from all 25 editions of the Polish Olympiad in Informatics, over 83% are available in English right now. I really hope that we can reach 100% later this year to celebrate the 25th birthday of the POI, but I don't want to promise anything.

Enjoy!

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By kostka, 17 months ago, In English,

The famous book with tasks from the polish programming contests can be ordered again. This time the book was printed in a more reasonable amount :)

https://ksiegarnia.pwn.pl/Looking-for-a-challenge-The-ultimate-problem-set-from-the-University-of-Warsaw-programming-competitions,748491781,p.html

Enjoy!

Update: I just noticed that books cannot be delivered outside Poland. We will do something about this. :P

Update 2: Check out this blog: http://codeforces.com/blog/entry/59876

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By kostka, 18 months ago, In English,

Hey everyone,

I know that nearly everyone is looking towards China right now, but let's try (like in a previous year) to create a list of IOI 2018 participants.

The list can be found here: http://weaselcrow.com/pro/cf/ioi/18/

How to add or update data? Please fill the following form: https://goo.gl/forms/he4DlrzfKWw35lx73

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By kostka, 2 years ago, In English,

Just in a month from today, IOI in Iran will start.

Below you can find the complete list of participants (based on registration and data provided by Codeforces community): http://weaselcrow.com/pro/cf/ioi2017/

Some random facts:

  • 326 students from 84 countries will participate (this will be a new record, the previous record was at IOI 2015 in Kazakhstan — 322 contestants from 83 countries)
  • El Salvador, Iceland, Morocco, and Palestine will send their contestants for the very first time, welcome to IOI!
  • 114 (almost 35%) participants were already in Russia, including golden medalists: reyna, yutaka1999, pacu, natsukagami, also Cyprus and Bangladesh will have exactly same team, as in previous year.

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By kostka, 2 years ago, In English,

Maintaining tradition from last year and the year before last I want to start a list of participants of the International Olympiad in Informatics 2017.

This year IOI will be held in Tehran, Iran between 28th July and 4th August.

Official website: http://ioi2017.org/

Facebook page: ioi2017.org


Update:

Check out the new version of this list with sorting and CF rating (updated by CF API):

http://weaselcrow.com/pro/cf/ioi2017/


Feel free to add (confirmed!) participants from your country here: https://goo.gl/forms/4BskHKHmZ70Tdck22 (preferred way) or below, in comments.

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By kostka, 3 years ago, In English,

This topic is probably as old as programming itself, but maybe someone can help me.

I had an opportunity to organize several camps for some pupils (age 14-16). They were pretty good in mathematics and puzzles in general. My job there was to show them why programming (and algorithms) is also pretty decent.

I show them some problems, teach them basic programming skills, but after several years I noticed that the most important thing in teaching such things is showing them why programming is important and why should they learn this. I should sell them not knowledge, but attitude during this week.

Do you have any idea how to convince younger generations why they should start programming? Why did you start? What is convincing you to still solve algorithmic problems?

Happy New Year and thanks in advance for your responses and ideas :)

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By kostka, 3 years ago, In English,

In next week, Baltic Olympiad in Informatics 2016 will be held in Helsinki, Finland.

The Baltic Olympiad in Informatics (BOI) is a programming contest for secondary school students. It started in 1995 with only 3 participating countries and grew substantially over the years. Now BOI encompasses about 60 participants from 9 countries situated around the Baltic Sea. Each country is invited to send up to 6 participants to the Olympiad, and the host country usually sends two teams. (from BOI 2015 webpage).

The contest website: https://www.cs.helsinki.fi/group/boi2016 and facebook page: https://web.facebook.com/boi2016/

Even Codeforces Round #352 is taken into account in schedule!

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