By narcis_vs5 days ago, In English,

Hello everyone,

I'd like to invite you to participate in a 2-hours Div2 round which will be held this Saturday, August 30th at 11:30 AM MSK. Div1 coders can take part out of competition, as usual. The problems were prepared by me and MirceaFF (B and C). I'd like to thank Gerald for helping preparation, MirceaFF for english translation and MikeMirzayanov for the Codeforces system.

The main characters of this round will be Caisa and Gargari,which have some interesting tasks for you. I hope you will enjoy the round. Good luck and have fun!

UPD: It will be used a standard scoring.

Here are the winners:






Stats about hacks can be found here.

Editorial is here.

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By BYN8 days ago, In English,

You enjoyed Bayan Programming Contest 2012-2013? Now we are happy to unveil Bayan Programming Contest 2014-2015! This will be Bayan's 3rd public programming contest and we have made several improvements and did our best to make the whole tournament even more fun! To register visit right now!

Introducing the rounds

Bayan Programming Contest We are going to host 5 rounds:

  1. The first round is named Shortcut!. Shortcut! round is mainly meant to help us actively test our new contest platform, but since we'd like to thank all the people participating in this round, the winner will bypass "all" intermediate rounds, and directly advance to the final onsite event! Top 5 contestants will also get a T-shirt. Shortcut! round is not going to be too hard and there is only 1 hour to solve 3 problems, making it harder to predict the round winner!

  2. Warm-up is our second round and honoured to be hosted on Codeforces. Warm up is also not a required round but it is going to be rated for both divisions and the top 50 are going to win t-shirts.

  3. Bayan Programming Contest officially begins with the Qualification round. It is going to be an easy event, and solving one problem is enough to advance to Elimination round. If you missed Shortcut! Round, make sure to get familiar with our new platform during this round. Also, 5 random participants will be receiving t-shirts.

  4. Elimination round is the most challenging online round in this tournament. Top 100 participants will be receiving t-shirts, but only top 20 from 20 countries will get the chance to compete in the final (onsite) event.

  5. Final round will be an onsite event. To find the onsite event's look and feel, you can watch this 4 minute video clip. More details will be announced later.


Shortcut! Round Terms & Rules

  • Shortcut! round will start at 13:00 UTC, 29 August 2014.
  • Shortcut! round consists of three programming tasks and competitors will have just one hour to solve them.

Solving Problems

  • Competitors may solve problems by any means and are free to use any programming language, library or computational application to solve problems. Given an input file, you should submit a correct output together with the source code used to produce that output within the specified time limit.
  • Not submitting any file during the time limit, will be considered as an unsuccessful attempt.
  • Both input and output formats are crucial. Adhere them precisely to avoid getting solutions judged as wrong.


  • Competitors may not use more than one user account.
  • Competitors may not communicate with each other during the contest.
  • Your output must be reproducible using the source code you provided.
  • All submitted source codes will automatically get analyzed for code plagiarism detection.
  • Cheaters will be banned forever from Bayan programming contests.


  • Do not submit irrelevant clarifications during the contest.
  • The decision of the judges are final in all matters.
  • All source codes of the competitors will be published after each round.
  • Bayan's staffs are not allowed to participate in the contest.

Score Calculation Method

Score for each solved problem is calculated based on these values:

  • n = No. of accepted submissions
  • t = Contestant's submission time
  • T = Total contest duration
  • p = Number of contestant's wrong attempts

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By hogloid10 days ago, In English,

Hello everyone!

snuke, wolf_sothe and me would like to invite you to Codeforces Round #263 for both divisions. It will be held on Tuesday, August 26th at 18:00 MSK. Note that this round starts on different time from normal rounds.

Great thanks to Gerald for helping us prepare the round, MikeMirzayanov for creating a fine platform, and Delinur for translating the statements.

You'll help men named Appleman and Toastman in this round. Good luck and have fun!

UPD. In Div.1 and Div.2, scores will be standard, that is , 500-1000-1500-2000-2500 for each problem.

Now the contest is over! Thank you for participating!

Here are the winners:



  2. sankear

  3. dreamoon

  4. Egor

  5. Memset137


  1. yyt16384

  2. SuzuKuma2112

  3. pawky

  4. AlexandruValeanu

  5. mosiomohsen

Congratulations on WJMZBMR, who solved all the problems !

Editorial is here

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By Neodym2 weeks ago, translation, In English,

Hello, CodeForces! On 20 August at 19:30 MSK will take place 262 (Div. 2) round. Div1 — participants can take part out of competition, as usual.

The problems were prepared by Victor Vasilevsky(vitux) and Aliaksei Semchankau (me). We'd like to thank Gerald Agapov (Gerald) for help of preparation of this round, Michael Mirzayanov (MikeMirzayanov) for comfortable platformes Codeforces and Polygon, and Mary Belova (Delinur) for translation of statements.

In this round you will help to different good people. We sure that every participant will find an interesting problem for him:)

gl & hf!

UPD: It will be used a standard scoring.

UPD2: Also we'd like to thank Vitaly Aksenov(Aksenov239) who helped a lot in fixing of Russian statements.

UPD3: We'd like to congrat top-5 participants!:

1) buptcjj

2) 6wr1

3) ladvnlt

4) shaojj

5) linjek

Also we'd like to congrat jellygendut, who got 20th place and solved problem Е — It has been solved by 3 participants. Nobody has solved all problems, but every problems were solved by participants succesfully.

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By MikeMirzayanov2 weeks ago, translation, In English,

Dear friends, you might have noticed that the VK logo has disappeared from the Codeforces pages and all of a sudden the place got sort of empty and a little bit gloomy. By the way, it happened not because the VK company lost the interest towards Codeforces and programming contests. Not at all. On the countrary, we have great plans to carry out together! We are infinitely grateful to the VK company for the 4 years of help and support.

We are glad to inform you that now a wonderful company called Telegram is going to help Codeforces. The company is founded by Pavel Durov and it united many brilliant developers with a rich olympic past. It is pleasant and important for us to see Codeforces helped by the people who understand programming contests, love them and value the skills of the community members. The Codeforces team is happy to get the opportunity to continue working and promises to continue dazzling you with contests, innovations and improvements.

Mike Mirzayanov and the Codeforces team

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By Erfan.aa3 weeks ago, In English,

Hello everybody!

I just want to invite you to participate in Codeforces Round #261 (Div.2 only), which will be held on August 15th, 19:30MSK.

This round is prepared by ShayanH, Haghani and me. Special thanks to mruxim for helping us to prepare the problems. Actually, this is our first round and we hope you'll enjoy the contest.

Traditionally, we thank Gerald for helping us to get the contest prepared and also MikeMirzayanov, for the great Polygon system.

Main characters of our stories are two interesting persons, named "Pashmak" and "Parmida"; such a lovely couple! <3

Score distribution will be announced soon.

Have fun. ;)

UPD1: Dynamic scoring system will be used.

UPD2: We recommend you to read all problems, although they're sorted by their estimated difficulty.

UDP3: We also thank Aksenov239 who helped us a lot in fixing the Russian statements.

UDP4: It's over!

Congratulations to all people who solved the five problems.

These are the 7 top official contestants:

  1. vanhanh.pham

  2. ElemeNtLz

  3. MLboy

  4. mssjtxwd

  5. yyfkiller3

  6. phidang

  7. roben_76

Editorial will be published soon.

UDP5: We're sorry for the delay. We put a brief editorial here.

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By SkidanovAlex3 weeks ago, translation, In English,

Hello everyone!

The second round of MemSQL Start[c]UP 2.0 will take place today, August, 10th, 10:00am PDT. There will be two contests running simultaneously, one for people who participate onsite, and one for everybody else who advanced to the round two. Both rounds share the problemset and are rated based on the combined scoreboard.

Onsite participants will have special prizes for first three places. All onsite participants as well as the top 100 in the online contest will receive a start[c]up t-shirt.

People who have not advanced to the round two can participate in the round unofficially. Unofficial participation will be rated.

The contest will be 3 hours long, and will feature 6 problems. The score distribution is 1000-1000-1500-2000-2500-3000.

Good luck and happy coding!

UPDATE: final results will be delayed.

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By fk20124 weeks ago, translation, In English,

Hi everyone!

We invite you to participate in Codeforces Round #260(Div. 1 and Div. 2), wich will take place on August 8th, 19:30MSK.

The round was prepared by me, netman and Randrew. It's our first round and we hope that tasks will be intresting for you). Special thanks to Gerald, Cherrytree, vlad107 and dimad for helping to prepare the round. Also MikeMirzayanov for creating such a good platform.

Good luck everyone!

UPD. In Div. 2 and Div. 1, scores for each problem will be 500-1000-1500-2000-2500.

UPD. We are sorry for the large queue in the end of round.

UPD. Congratulations to the winners.

Div. 1

  1. tourist

  2. cgy4ever

  3. LayCurse

  4. ecnerwal

  5. snuke

Div. 2

  1. dtalamas24

  2. gotowork

  3. SMAKH

  4. saikrishna17394

  5. PashaChemerys


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By xiaodao5 weeks ago, In English,


Codeforces Round #259 (Div. 1 and Div. 2) will take place on August 1st, 19:30 MSK.

Setters are: sevenkplus, xlk and me.

Testers are: vfleaking, GuyUpLion, ztxz16 , CMHJT and Trinitrophenol.

Many thanks to Gerald for his help in giving advise about the problems. And we gratefully acknowledge MikeMirzayanov and his team, who bring us the world best competitive programming platform!

Tonight, you will come to Equestria and help our Friendship Princess — Twilight Sparkle to solve those intractable challenges one after another.

Twilight Sparkle is a main protagonist of the series — My Little Pony: Friendship Is Magic.

She is a female unicorn pony who transforms into an alicorn and becomes a princess in the third season of the series. She has a cutie mark of a 6-pointed magenta star with a white one behind it and 5 more smaller ones at each end of the magneta star.

Of course, I guarantee not knowing the storyline and setting won't hold you back from solving these problems~


In Div. 1, scores for each problem will be 500-1000-1500-2500-2500.

In Div. 2, scores for each problem will be 500-1000-1500-2000-2500.


Contest is over! Congratulations to the winners! Here are the top 6 in Div.1 division:

  1. Petr

  2. msg555

  3. cgy4ever

  4. dzy493941464

  5. kcm1700

  6. Jacob

And here are the top 6 in Div.2 division:

  1. laomao

  2. AcySbl

  3. mpp121

  4. nuip

  5. chenzeyu97

  6. hcretescu

Editorial is here.

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By dj35006 weeks ago, In English,

Hi! In this post I would like to introduce you to an application called Hightail.

Hightail is an automatic tester for programming contests such as CodeForces rounds. It will parse the problem statement, extract sample test cases (inputs and outputs) from it, and verify the correctness of your program against them. It is built to provide maximum automation and to relieve the contestant as much as possible.

A list of Hightail's features:

  • parsing problem statements
  • parsing entire contests (autoloading all problems)
  • scheduling contest parsing ahead of time
  • ability to comfortably view, edit and add test cases
  • handling of all verdicts: WA, TLE, RE, even AC
  • customizable time limits
  • ability to create in/out files in your working directory
  • detection of floating point values (comparing 0.1 vs. 0.10 does not give WA)
  • easy-to-use UI, keyboard shortcuts
  • resilient: it is multi-threaded so it will not let your program hang it; it will withstand large amounts of output from your program
  • support for all contest languages (C++, Java, Python, ...)
  • written in Java and should run on any OS

Some screenshots to give you an idea:

Screenshot 1 Screenshot 2

You will find more information on its homepage (scroll down to see the readme). And here's a direct link to downloads.

Hightail started out as a simple program that I wrote for myself quite some time ago, then it became a small open source project when some other people contributed code to it. I think that it is now sufficiently developed that it can be released to the public, i.e. announced publicly here, rather than being hidden somewhere on the net, possible to find only if you already know the name. (It's probably long overdue, actually.)

If you see bugs, have feature suggestions etc., please use GitHub to its fullest extent :) And look at the readme — it has a tutorial on how to contribute to Hightail.

I hope it will be useful to you :)

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