Our community keeps on growing and gaining in popularity! We are glad to announce that Codeforces has recently registered its one hundred thousandth user. Thanks to everybody who keeps the project going — the problem writers, testers, corporate partners and of course all members of the community. Our special gratitude is to the VK.com company!

One cannot get enough of the good statistics. Here are some more numbers:

• our database contains more than 3.5 millions of your submitted solutions,
• the number of problems comes near 3000,
• the number of site visitors per month excedes 400000,
• the number of page views per month amounts is approximately 5000000.

The first information letter

General information

In the first part of August 2013 Saratov State University runs an international student summer school in computer programming. The exact dates are 5-15 of August. Teams of three people and individual participants are invited to take part in it.

The school will take place in a picturesque place at one of Saratov resort centers on the Volga bank. The participants will be provided comfortable rooms for 2-4 people and meals three times a day. The resort center owns a beach and sport grounds.

It will be 10 training days. The school includes lectures by Saratov state university coaches, joint trainings, problems tutorials and topical workshops. The curriculum is designed for younger university students who aspire to achieve high results at programming competitions. Official language is Russian.

The fees are 16500 RUR (~ 525 USD) per a person. Moreover, each team or an individual participant should bring a laptop with the support of WI-FI.

All interested participants and teams should register at http://goo.gl/DHwqU till 15th June 2013. Don't postpone the registration, as the number of participants we can take is limited.

You can get additional information by e-mail mirzayanovmr[symbol-at]gmail.com. As since the official language of the school is Russian, the registration requires knowledge of Russian. Also it is recommended to view this page in Russian.

Hello everyone!

Codeforces Round #186 (Div. 2) will take place on Thursday, May 30th at 19:30 MSK. This is my first Codeforces Round and I hope that everyone will enjoy this round.

I would like to thank Gerald for helping me prepare this round. Special thanks to Delinur for translation of all problem statements into English.

Problems point values today is: 500-1000-1500-2500-2500

Good luck & have fun! :)

Hello,everyone!

Codeforces Round #185 will take place on Sunday, May 26th at 19:30MSK (23:30CST).

This round is initiated by zanoes, and here are the problem setters:

• Div.1E & Div.2B —— zanoes (**Zhang Gaoxiang**)
• Div.1D & Div.1A —— liouzhou_101 (**Wang Qisheng**)
• Div.1C & Div.1B & Div.2A —— lydrainbowcat (**Li Yudong**)

Testers are roosephu(Luo Yuping), FredaShi(Shi Haoyue), sjynoi(Sun Jiayu), sevenkplus(Gu Yuzhou), MinakoKojima(Tang Feihu) and Riatre.

Especially thanks Gerald for helping us to prepare the round, MikeMirzayanov for the great platform and Delinur for translation.

Score will be standard, 500-1000-1500-2000-2500 in both divisions. In our opinion, problems are easier than the past several rounds prepared by Chinese)

This is our first Codeforces round, I hope you can enjoy it. Wish you high rating and good luck!

UPD: We feel really sorry about the mistake we made. The following words were written by Div.1A (Div.2C)setter, liouzhou_101. http://codeforces.net/blog/entry/7773#comment-134702 .

Meanwhile, It's also zanoes's and my fault that we didn't check his checker carefully, even brought troubles to Codeforces flat. I beg your forgive for liouzhou_101, for he also tried to prepare the round well these days.

UPD2: The round will be unrated.

Editorials will come out soon. Now you can find some of the editorials here: http://codeforces.net/blog/entry/7785

Contest is over. Congratulations to the winners.

Div.1

1. zfmdhy786 (I promise it's someone who pretends to be roosephu, and I've known who he is.)
2. cp12321
3. RAD
4. ACMonster
5. kAc

And ryz , cgy4ever, who passed problem E in the contest.

Div.2

1. ymxlkAc
2. sasha.sochka
3. bohuss

Good evening, Codeforces.

Today I've added the first five contest of the famous Andrew Stankevich Contest series. They are available for virtual participation and practice.

I competed in several Andrew Stankevich Contests and I can say that these contests are always well prepared and consist of extremely interesting problems. You can really enjoy taking part in them.

Good luck and have fun.

P.S. All contests are available in Andrew Stankevich Contests group.

Direct links

Please note that all problems uses different input and output files. You can find correct input/output file names at the contest dashboard and in the statements.

• 2002-2003 Winter Petrozavodsk Camp, Andrew Stankevich Contest 1 (ASC 1)
• 2003-2004 Summer Petrozavodsk Camp, Andrew Stankevich Contest 2 (ASC 2)
• 2003-2004 Summer Petrozavodsk Camp, Andrew Stankevich Contest 3 (ASC 3)
• 2003-2004 Winter Petrozavodsk Camp, Andrew Stankevich Contest 4 (ASC 4)
• 2003-2004 Winter Petrozavodsk Camp, Andrew Stankevich Contest 5 (ASC 5)
• 2003-2004 Winter Petrozavodsk Camp, Andrew Stankevich Contest 6 (ASC 6)
• 2004-2005 Summer Petrozavodsk Camp, Andrew Stankevich Contest 7 (ASC 7)
• 2004-2005 Summer Petrozavodsk Camp, Andrew Stankevich Contest 8 (ASC 8)
• 2004-2005 Summer Petrozavodsk Camp, Andrew Stankevich Contest 9 (ASC 9)
• 2004-2005 Winter Petrozavodsk Camp, Andrew Stankevich Contest 10 (ASC 10)
• 2004-2005 Winter Petrozavodsk Camp, Andrew Stankevich Contest 11 (ASC 11)
• 2004-2005 Winter Petrozavodsk Camp, Andrew Stankevich Contest 12 (ASC 12)
• 2005-2006 Summer Petrozavodsk Camp, Andrew Stankevich Contest 13 (ASC 13)
• 2005-2006 Summer Petrozavodsk Camp, Andrew Stankevich Contest 14 (ASC 14)
• 2005-2006 Summer Petrozavodsk Camp, Andrew Stankevich Contest 15 (ASC 15)
• 2005-2006 Winter Petrozavodsk Camp, Andrew Stankevich Contest 16 (ASC 16)
• 2005-2006 Winter Petrozavodsk Camp, Andrew Stankevich Contest 17 (ASC 17)
• 2005-2006 Winter Petrozavodsk Camp, Andrew Stankevich Contest 18 (ASC 18)
• 2006-2007 Summer Petrozavodsk Camp, Andrew Stankevich Contest 19 (ASC 19)
• 2006-2007 Summer Petrozavodsk Camp, Andrew Stankevich Contest 20 (ASC 20)
• 2006-2007 Summer Petrozavodsk Camp, Andrew Stankevich Contest 21 (ASC 21)
• 2006-2007 Winter Petrozavodsk Camp, Andrew Stankevich Contest 22 (ASC 22)
• 2006-2007 Winter Petrozavodsk Camp, Andrew Stankevich Contest 23 (ASC 23)
• 2006-2007 Winter Petrozavodsk Camp, Andrew Stankevich Contest 24 (ASC 24)
• 2007-2008 Summer Petrozavodsk Camp, Andrew Stankevich Contest 25 (ASC 25)
• 2007-2008 Summer Petrozavodsk Camp, Andrew Stankevich Contest 26 (ASC 26)
• 2007-2008 Summer Petrozavodsk Camp, Andrew Stankevich Contest 27 (ASC 27)
• 2007-2008 Winter Petrozavodsk Camp, Andrew Stankevich Contest 28 (ASC 28)
• 2007-2008 Winter Petrozavodsk Camp, Andrew Stankevich Contest 29 (ASC 29)
• 2007-2008 Winter Petrozavodsk Camp, Andrew Stankevich Contest 30 (ASC 30)
• 2008-2009 Summer Petrozavodsk Camp, Andrew Stankevich Contest 31 (ASC 31)
• 2008-2009 Summer Petrozavodsk Camp, Andrew Stankevich Contest 32 (ASC 32)
• 2008-2009 Winter Petrozavodsk Camp, Andrew Stankevich Contest 33 (ASC 33)
• 2008-2009 Winter Petrozavodsk Camp, Andrew Stankevich Contest 34 (ASC 34)
• 2009-2010 Summer Petrozavodsk Camp, Andrew Stankevich Contest 35 (ASC 35)
• 2009-2010 Summer Petrozavodsk Camp, Andrew Stankevich Contest 36 (ASC 36)
• 2009-2010 Winter Petrozavodsk Camp, Andrew Stankevich Contest 37 (ASC 37)
• 2010-2011 Summer Petrozavodsk Camp, Andrew Stankevich Contest 38 (ASC 38)
• 2010-2011 Winter Petrozavodsk Camp, Andrew Stankevich Contest 39 (ASC 39)
• 2011-2012 Summer Petrozavodsk Camp, Andrew Stankevich Contest 40 (ASC 40)
• 2011-2012 Winter Petrozavodsk Camp, Andrew Stankevich Contest 41 (ASC 41)
• 2012-2013 Summer Petrozavodsk Camp, Andrew Stankevich Contest 42 (ASC 42)
• 2012-2013 Winter Petrozavodsk Camp, Andrew Stankevich Contest 43 (ASC 43)
• 2013-2014 Summer Petrozavodsk Camp, Andrew Stankevich Contest 44 (ASC 44)
• 2013-2014 Winter Petrozavodsk Camp, Andrew Stankevich Contest 45 (ASC 45)
• 2014-2015 Summer Petrozavodsk Camp, Andrew Stankevich Contest 46 (ASC 46)
• UPD 2014-2015 Winter Petrozavodsk Camp, Andrew Stankevich Contest 47 (ASC 47)

You remember the cool promotional videos (in Russian) on the All-Russian Open Programming CROC 2013 Championship, right? This time CROC amazed us and sent us an after-the-championship video. Someone here might find him/herself in the video and someone just might be interested to see the way it was.

Besides, there is a complete photo archive.

In conclusion, I am glad to use this opportunity to describe my excitement at the way CROC works, their attitude towards the event, their professionalism and the achieved work! It was fun and easy to work together :) Our special gratitude goes to Sergey Strelkov, Georgy Mogelashvili and Maria Dovzhenko.

Hello, Codeforces!

Recently I joined the team of Codeforces developers. Today I want to tell you about first major feature implemented by me.

Now in your social profile (http://codeforces.net/settings/social) you can enter an organization you want to represent.

It can be university, college, school or any other organization. If you want to enter school, lyceum or gymnasium, please add a city to avoid any ambiguousness. For example: instead of PhTL #1 please enter Saratov, PhTL #1.

When you are filling the Organization field, please, use autocomplition and follow the tips. Or it will become a mess. And we will have to clean it up with TRUNCATE TABLE.

It is possible that one organization can have different names. Especially it is true for universities. You should try to avoid too short names, because they can lead to ambiguousness. For example: SSU can stand for Saratov State Universiry, Samara State University or Syktyvkar State University.

But long names are not very good too. Can you imagine how it will look if tourist will decide to enter the full name of his university: Saint Petersburg State University of Information Technologies, Mechanics and Optics? : )

As it is with countries, you will be able to see rating of organiztion and rating of users inside particular organization.

With best regards, Ivan

Last Friday, on May 17, CROC finishes the All-Russian Open Programming Championship. The CROC company (together with Codeforces) holds a competition for the best coders of our country for the second year in a row.

Informational technologies are a dynamic habitat where the best minds dwell and sometimes innovative ideas come up at a great speed! This time the organizers stated that the championship is all-Russian but they were surprised to see the championship interest extending beyond the national border.

The interest towards the competition was such that we had many participants from Russia, former Sovyet republics and even far away countries. On this championship, coders solve sports programming problems: to win, they need to come up with effective algorithms, code them quickly, consider all non-typical situations. Besides, there is the additional element of looking for mistakes in other participants' codes and suggest the tests that fail their rivals' codes. The special feature of the contest is the "Code Game Challenge" play round, for which we singled out a special day., — says Sergey Strelkov, the head of the CROC company software development department.

Dmitry Matov from Saratov was humble and skeptical about his chances to win, pointing out the high level of the Championship:

It's the second time I've taken part in the CROC championship. There are few such championships in Russia – you can count the companies that support spots programming like that on the fingers of one hand.

The CROC Championship took part in several stages: it started at the qualification round on April, 13 the internet elimination rounds took place on April, 15 and 22 and finally, the Championship Finals took place in the CROC Moscow office on May, 16 and 17.

The finalists included 3 participants from Belarus, 3 from Ukraine, 3 Polish and one Japanese coder:

The participants of the Finals had pleasant surprises ahead of them. They meet the championship organizers in the CROC innovative office, they went for an excursion to the CROC Data Analysis Centre and took part in an exciting play round:

--- The participants had to implement strategies for hockey teams with a goalkeeper and two players. They had quite little time to write a code that coordinates the players and then compete with other teams. It was interesting and it was fun! — says one of the finalists.

Gennady Korotkievich, a student of St. Petersburg National Information Research Institute of Information Technologies, Mechanics and Optics, won the IT hockey, and the Championship:

It was a challenging competition with challenging problems and challenging participants. That's what makes it interesting for the participants and I guess, for the spectators, too.

Besides, Gennady noted that the CROC Championship for young programmers is a great opportunity to compete with the best young programmers and communicate with people from other cities and even countries. Most of all, this provides the personal growth perspective as well as rising interest to sports programming in Russia.

We remind you that the winner was awarded with 100 000 rubles. Egor Kulikov and Evgeny Kapun, the participants who got the second and third prizes, won 70 000 and 50 000 rubles, correspondingly. The full results are available by this link.

The 2013 Open All-Russia CROC Championship is over. We congratulate the winners but we do not say bye! Look out for the CROC IT news to be among the best. And win!

Hello!

A few hours later, on May 19th at 17:00 MSK, you are lucky to participate in Codeforces Round #184 for Div. 2 participants. Traditionally, Div. 1 participants can take part out of the competition.

Problems have been prepared by: Gridnev Vitaliy (gridnevvvit), Ignatyev Alexander (aiMR). It’s our second round and I hope not last. We want to thank Gerald Agapov(Gerald) for help in preparation of this round, Michael Mirzayanov(MikeMirzayanov) for marvelous Codeforces and Polygon systems, Mary Belova(Delinur) for translating the problems.

We hope you will like these problems, and that it will be fun to solve them.

Also we strongly recommend you to read all the problems.

We wish everyone good luck and high rating!

UPD1: Scoring will be standart: 500, 1000, 1500, 2000, 2500.

UPD2: Editorial

UPD3: Congratulations to winners:

1. SillyHook06
2. hyplymac
3. HAPKOMAH

Today it will be Croc Champ 2013 Finals! Good luck to all participants. And to those who don't participate — enjoy the interesting competition.

Yesterday have finished the trial contest and Code Game Challenge. The winner of Code Game Challenge is ... tourist!

Also pay attention to the Croc Champ 2013 - Finals (online version, Div. 1). It will be a rated round. Note: it will be slightly unsual because we will not hide the standings of the official contest. So some information about difficulties of the problems will be known before the round. The contest duration is 2.5 hours.

Good luck to everyone!

The contest has been finished. The winners are:

• tourist
• Egor
• eatmore

Final standings