By ibra, history, 47 hours ago, In English,

Hi Codeforces!

As you already know from previous post, Bubble Cup is a programming competition organized by Microsoft Development Center Serbia for eight year in a row. And the finals is coming!

This year we came up with a wonderful idea to have an online mirror of the finals on Codeforces! We would like to thank MikeMirzayanov and Codeforces team for their work and support in making this happen.

The online competition will be held on 6th of September, Sunday 11-00 AM (Moscow time). The competition will last for five hours and it will run with the standard ACM ICPC rules. This will be a team contest on Codeforces, with teams consisting of one or two people. Amount of problems(7-10) will be anounced later.

Contest was mainly prepared by employees of MDCS (+ special thanks to knightL for help).

This contest will be unrated (mostly because rules of this contest and not usual for Codeforces (and it is first time we organize this kind of mirror).

10 best teams will receive our special T-shirts (each team member) +10 t-shirts will be handed out randomly to other participants of the top 100.

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By DuX, 9 days ago, In English,

Hello Codeforces,

In less than a two weeks, finals of 8th edition of Bubble Cup will be held in Belgrade, organized by Microsoft Development Center Serbia.

Unfortunately, there wont be Bubble Run contest this year (which was held last two years for university students in the same tame as BCup, and it was a 24h marathon style contest), but only ACM-style 5 hour long contest for both university and high school teams in the same category. You can read more about contest on the official website, and read tasks and solutions from past years in the booklets. (There are some very interesting tasks, especially from Run contests, so I encourge you all to take a look at them).

Usually, the contest was interesting only to teams from Serbia and it's region, but every year we can see more and more teams from other countries participating in qualifications, and now there will be teams from 7 different countries from Eastern Europe participating in the finals, which is the most I think. Certanly, it will be the toughest Bubble Cup ever, and that's the reason why I'm listing teams here. I hope there will be even more strong teams from other countries next year!

The new cool thing this year will be a BC conference where we will hear talks about competitive programming and maybe something more, from Psyho (SomeGuyTookMyHandle), misof and MikeMirzayanov! (I can't wait for this! :D). Also, there will be a big party after the contest as MDCS celebrates 10 years anniversary.

For teams and guests who will come to the finals: Hope you will enjoy Belgrade and Serbia, and if you want to go to some fun places here, hang out, or maybe even spend few more days in this beautiful city, I'll be glad to help you :) If you have any questions, just post it in the comments, or send me a message. See you soon!

Teams (sorted by bonus penalty time):

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By Errichto, 5 days ago, In English,

Hello Codeforces community!

Codeforces Round #318 (for both divisions) will take place on August, 29 at 19:30 MSK. It is the Thanks-Round devoted to Russian Code Cup. You will be given 5 problems and 2 hours to solve them. Scoring will be announced close to the round. I strongly recommend you to read all problems.

RussianCodeCup is the largest open programming competiton for Russian-speaking participants by Mail.Ru Group. Its history started in 2011. And since the first championship RCC offers great problems and generous prizes. This year finals will be held on September, 19th. Wish good luck to all the finalists! Thank you, RussianCodeCup, for your gift on the 5th anniversary of Codeforces!

I am honoured to be a problem setter for this round. I wouldn't do it alone. I want to thank Zlobober for his great help with problems preparation and MikeMirzayanov (and all people working on Codeforces and Polygon) for this awesome site. It's an amazing place to learn and compete. My big thanks to winger and AlexFetisov for their help with testing a round. And to Delinur for translating statements. As you see, not only a setter creates a round.

It's my first Codeforces round but not my first problems here. You can check out A, C and D from VK Cup 2015 — Round 2. Also you might remember some of my problems in TC rounds. I'm very happy with finally preparing a full round for Codeforces and I hope you will enjoy it. I tried my best to prepare nice and diverse problemset, you will judge it. In all problems you will have to help Limak who is quite unusual bear.

I wish you great fun and no frustrating bugs. Looking forward to seeing you!

UPD: Scoring is 500-1000- 1750 -2000-2500 in div1 and 500-1000-1500-2000- 2750 in div2. Enjoy a round!

UPD: Editorial

UPD: Contest is over. The winners:


  1. Marcin_smu
  2. mnbvmar
  3. subscriber
  4. LoneFox
  5. Shef


  1. cesc (5 problems solved!)
  2. fhxb520630 (5 problems solved!)
  3. bugCollector
  4. Izaron
  5. okaduki1

And note from an author. There were some wrong solutions passing. Sorry for that. I tried my best to create strong tests but I failed a bit. Did you like this round? What do you think about problems?

Thanks for participating!

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By zeliboba, 2 weeks ago, translation, In English,

Hi, Codeforces!

Codeforces Round 317 will take place on August, 22 at 19:30 MSK.

The round is prepared by AimFund employees: Kostroma, AlexDmitriev, yarrr, gchebanov, ArtDitel, Baz93 and zeliboba.

Scoring system will be static.

Thanks to Mike Mirzayanov(MikeMirzayanov) for brilliant platforms Polygon and Codeforces, problem coordinator Max Akhmedov (Zlobober) and Maria Belova (Delinur) for English translation.

Top 200 div1 participants will be awarded t-shirts. To learn more about AimFund please refer to our previous post.

This round is prepared as part of "5 years" Codeforces program as our present to community. This round is the first Thanks-Round devoted to companies donated significant money.

We wish you good luck and high frequency rating!

P.S: scoring 1 div 750-1250-1500-2000-2750. 2 div 500-1000-1750-2250-2500

P.P.S. Top-20 div2 participants will be awarded t-shirts.


P.P.P.S. Dear friends. We are pleased to inform you that t shirts delivery will be under way next week. We hope you will really like them. Our sincere congrats again to you all!

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By rng_58, history, 3 weeks ago, In English,

GCJ will start in less than 24 hours.

Live Stream:

Unfortunately I don't have time to edit this table, but rowdark will participate, and izrak won't.


GCJ Handle Country CF Handle CF Rating TC Handle TC Rating R2 Rank R3 Rank Previous Finals
Gennady.KorotkevichBelarustourist3503tourist3766132014 (1st)
vepifanovRussiavepifanov2963Kankuro323233102011 (8th),
2012 (4th),
2013 (17th),
2014 (8th)
rng..58Japanrng_582941rng_583468312010 (7th),
2011 (1st),
2012 (19th)
bmerrySouth Africabmerry2722bmerry329560112008 (3rd),
2009 (10th),
2010 (21st),
2012 (6th)
dzhulgakovUkrainedzhulgakov2607dzhulgakov3168142142008 (44th),
2009 (5th) 2012 (9th),
2013 (13th),
2014 (9th)
pashkaRussiapashka2488pashka286211152008 (84th),
2009 (17th),
2010 (8th),
2011 (7th)
RomkaBelarusRomka2452_Romka_2474446282014 (10th)
iwiJapaniwiwi2427iwiwi3100762008 (59th),
2010 (9th),
2014 (15th)
tczajkaPolandtomek2393tomek32041872003 (4th),
2004 (4th),
2006 (6th)
JAPLJJapanwrong2367wrong246567222013 (23rd)
wuzhengkaiChinawuzhengkai2343wuzhengkai2575135232014 (23rd)
XharkSouth KoreaXhark2132Xhark1677354
linguoUKlinguo3652008 (74th),
2010 (22nd),
2011 (22nd)

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By josdas, history, 3 weeks ago, translation, In English,

Greetings to the Codeforces community!

Regular Codeforces round #316 for participants from the second division will take place on August 13, 19:30 MSK. Participants from the first division are able to participate out of the contest.

It is my first round on Codeforces. Hope you will enjoy this round.

I want to thank Max Akhmedov (Zlobober) for help with preparation of this round, Maria Belova (Delinur) for translation of statements and Mike Mirzayanov (MikeMirzayanov) for great Codeforces and Polygon systems.

Participants will be given five problems and two hours to solve these problems.

UPD: The score distribution is standard, 500-1000-1500-2000-2500

Good luck!

UPD: Contest is finished. Thank you everyone!

Congratulations to the winners!

UPD Editorial

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By Um_nik, history, 3 weeks ago, translation, In English,

Hello everyone!

Codeforces Round #315 will take place soon. The authors of this round are students of Ural FU Umqra and Um_nik. This is our second round. First one was in the black days of Codeforces and we hope that this will not happen again after our round :)

We want to thank Codeforces team for great Codeforces and Polygon platforms and Zlobober for helping us prepare this round.

Good luck!

Score distribution.
div2 : 500-1000-1500-2250-2750
div1 : 500-1000-1500-2250-2500
We strongly recommend you to read all the problems. We try our best to prepare different problems and some problems that hard for us can be easy for you.


Congratulations to the winners!

1. KAN
2. Petr
3. enot.1.10
4. tonyjjw

1. Amdi
2. loser21
3. Aliquando
4. hqpwca
5. Lone_Wolf_LZ

Thank you for participating.

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By P1kachu, 4 weeks ago, translation, In English,

Hello, Codeforces!

5th august 2015 at 19:00 MSK Codeforces Round #Pi will take place for second division participants. Participants from the first division are able to participate out of the contest.

This is my first round on Codeforces. I hope you will enjoy the tasks and this will stimulate me to prepare new rounds! Wish you quick Accepted verdicts and successful hacks.

I want to thank Michael Mirzayanov (MikeMirzayanov) for wonderful platforms Polygon and Codeforces and for help in preparing the tasks, Maxim Akhmedov (Zlobober) for help in contest preparation, Maria Belova for translation statements to english, and also my friends Danil Sagunov (dans) and Vitaliy Kudasov (kuviman) for solving the tasks.

Participants will be given six tasks and two and the half hours for solving them. Scoring system will be announced closer to round start.

UPD: Scoring: 500-1000-1500-2000-2500-2500.

UPD Editorial

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