Codeforces Testing Round 5 starts on Jan. 12, 2013, 15:00 (UTC). Our goal is to test the platform after recent improvements. You may notice that we've improved real realtime status. You may visit (problemset status)(http://mirror.codeforces.com/problemset/status) and find that it updates automatically without page reloadings. It uses modern web realtime technologies like websockets and so on. For sure, no server polling!

Also we've updated server software and built Codeforces with Java 7.

I invite you to take part in the round. It will be Div. 2 + unofficials from Div. 1. It will contain three obsolescent problems. But I think it will be interesting for many of you. The problems contain very weak pretests to force more hacks. It will be unrated round.

Many thanks to participants!

P.S. As it is testing round, we do not guarantee stable work and so on.

Calendar: (c) 2011 Anatoly Rr

The Codeforces project wishes all its users a successful New Year. May all your handles change the colors only towards red, may all your solutions go well without debugging and may you enjoy many times the coveted Accepted at each contest! We wish you good luck in everything you do next year — isn't that great to have luck on your side!

Traditionally, the Codeforces enables the users to change their handles. Note that this is a one-time change and you won't be able to return to the previous handle. Analyze all 'for' and 'against' carefully as the handle is what you are going to be often called by the numerous participants of the Codeforces contests.

We've got more good news. We've decided to increase the list of people who can get the role of the 'coach' in the Codeforces project::training. Check out all those training sessions! Now this role can be given to those who:

• have got the red color handle (i.e. the rating of at least 2200),
• have got the orange color handle, have participated in a Codeforces official contest not more than six months ago and have taken part in at least 30 rated Codeforces contests).

This innovation is going to increase the number of potential coaches roughly by two!

And the last, but not the least detail. Now we can increase the authors' fees for preparing contests. That will hopefully give a little motivation to those who can make an interesting round. In 2013 the authors' fees is:

• preparing a Div.1 + Div.2 round (USD): 250 + 50*,
• preparing a Div.2 round (USD): 100 + 50*.

(We use fixed rate USD = 40 rubles, so actual payment may differ slightly). The sums with asterisks are the extra bonuses the author gets for 'good quality'. The author receives the bonus if he worked without jeopardising the deadlines for preparations and the round went without any major problems with the statements (no additional major notices, fixes in solutions/tests/checkers/validators etc.).

We hope to work with authors efficiently in 2013, we hope that our best participants will generously dazzle the community with interesting contests! For more information or to organize a context, please message Codeforces problem coordinator Gerald (Gerald Agapov).

Happy New Year!

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:

• 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 Codeforces company to carry out the Open Moscow City and Moscow Region Programming Championship, around 1500 participants!
• the ABBYY company has used the Codeforces platform to carry out the ABBYY Cup 2.0 championship, around 2000 participants!
• we've introduced attaching blog posts to contests as announces, tutorials etc.
• we've semiautomatically attached the tutorials for the past contests
• the Bayan company has used the Codeforces platform to carry out the sorting stage of Bayan Programming Contest 2012/13, more than 3000 participants!
• the CROC company has used the Codeforces platform to carry out the CROC Programming Championship among the Bauman MSTU, around 2000 participants!
• the testlib.h has come through numerous improvements
• we've supported new programming languages
• we've supported the dynamic problem complexity
• we've supported inserting photo albums from Picasa to posts
• we've supported interactive problems — despite the short wording, this point is hugely important
• the Polygon project has come through numerous improvements
• we've supported problems with the score in points and with partial solutions (for the marathon type contests)

And that's not the end! We are glad to demonstrate to you wonderful pictures with pleasing graphs and charts.

Northeastern European Regional Contest 2012 will start on December, 2nd. We wish good luck to the teams and many joyful moments to the funs!

Useful links:

• standings
• Petr Mitrichev blog
• Online translation of Awards Ceremony

NCPC (Nordic Collegiate Programming Contest) — the annual programming competition for universities and colleges in the Nordic countries. The event itself is organised in a distributed manner. It is physically hosted at many participating universities and colleges. The same problemset is used at all sites. The scores are gathered electronically, and the result is simultaneous local, national and Nordic championships.

The organizars publish the problems and testdata, special thank you to the organizers.

The contest of this year is available in Codeforces::Gym — 2012 Nordic Collegiate Programming Contest (NCPC)

It is really good contest as a training before the Subregional or Regional ACM-ICPC contest.

Right now the onsite contest is in progress. You can view the curreny results here.

On Monday you can take part in unofficial contest mirror on http://acm.sgu.ru/. The contest starts on October, 22 (Monday), 2012, 12:00 (UTC). The official results will be integrated into the online contest standings. Hope to see you on [http://acm.sgu.ru/]!

Later the contest will be added as a training in Codeforces::Gym.

Recently the first third team NEERC Trains was finished. By the way, the first place got the intriguing team "SPb NRU ITMO 1: Kever, Korotkevich, Nigmatullin" :-) It was used Warsaw contest from old contest Petrozavodsk camp.

I've added 2007-2008 Petrozavodsk Winter Training Camp, Warsaw Contest to the Gym. The ghosts are not only Petrozavodsk camp participants (2008) but also modern ITMO teams!

Enjoy the contest before ACM-ICPC Subregionals and Regionals contests.

Being recently in the CROC office, I've heard about another interesting contest. It's called "Flying Robots". I am far from robots, but the subject is interesting and popular. I am pleased to publish a small announcement.

About contest

September 3, 2012. CROC, one of the five largest IT companies in Russia, calls for Flying Drone contest applications. The contest is a part of the '20 Ways to Brighten Up Your Life' project. The first prize will be 1 million Rubles.

Contestants shall make a pilotless and autonomous drone which must take off from a starting point, overcome an obstacle, land within a certain zone, take off again and then come back to the starting point. Please submit your application till November 15, 2012. For contest details please visit http://robots.croc.ru/ (in Russian).

Results announcement and award ceremony will take place in August 2013.

About CROC

CROC is a leader in IT infrastructure design and implementation and the number one systems integration service provider in Russia (IDC reports, 2002-2011). CROC is one of the five largest IT companies in Russia (RIA Analytics 2012, Expert Rating Agency 2011) and one of Russia’s Top 200 Private Companies (Forbes).

Hello!

Only few hours left before Codeforces Round # 135 (Div. 2). We are preparing the round in Petrozavodsk where traditional training camp for ACM-ICPC is going now. Today is a day of rest here, many participants gone to a trip to Kizhi. The main contest authors are me and Gerald. Special thanks to Aksenov239 who tested the round. Thank Delinur for translation.

The problems will be sorted by expected difficulty, the scores are dynamic.

Wish you fun round!

There is something to boast. If you count the number of active participants as it TopCoder does (at least one participation in a rated-event in six months), then for Codeforces it is 9389. By the way, TopCoder has a little less, 9380. A trifle, but nice! :)

Distribution by colors:

Hello!

You may find the photos from the VK Cup 2012 on http://vk.com/vkcup

Today is the main VK Cup event: VK Cup 2012 Finals! Good luck to all participants. And to those who don't participate — enjoy the interesting competition. VK CEO Pavel Durov announced the upgrade of a prize fund in the greeting speech at the finals' opening! I'm starting to really regret that I am not a participant.

The participants compete for:

• 1st place — $30000
• 2nd place — $20000
• 3rd place — $10000
• 4-5 places — $2000
• 6-10 places — $1000

Good luck! Wish you only positive emotions. Ready! Steady!...

UPD: The contest is over! I believe Alex_KPR will write about the contest and the closing ceremony soon. Thank you for participation and your interest. Here are the complete standings.

Congrats to the winners. The top-3 is:

• sevenkplus (Yuzhou Gu) China
• s-quark (Qinshi Wang) China
• tourist (Gennady Korotkevich) Belarus

UPD: As you have already noticed, the 16th July at 19:00 will start an unofficial online-version of the VK Cup 2012 Finals. Anyone can participate and feel himself as a finalist. Round will be unrated. If you already took part in the Finals or familiar with the problems, please refrain from participation. All problems will appear in the archive and will be available to everyone.

Hi everybody!

Today, on the 14th of July, we hold a trial round of the VK Cup 2012 final championship round. The Codeforces functionality is very limited for the external visitors and for the finalists. Please stay calm.

The participants of the Finals do not have to register for the round. There are no special pep talks — you will face the familiar system with the usual settings. Oh yes, the system of assessing tasks will be dynamic. Let me remind you that you should not use any electronic devices or personal records, communicate with each other et cetera. You shouldn't violate any rule Codeforces and VK Cup rules. Tomorrow is a big day, let's rehearse it in all details.

MikeMirzayanov and the VK Cup 2012 jury team

Hi everybody!

The VK Cup 2012 programming championship finals is going to take place very soon. The organizing committee and jury are working around the clock to set up the event that the participants will like.

Let us remind you that the finals will take place from July, 13 to July, 16. We will choose the best 50 participants by the results of VK Cup 2012 Round 3. As soon as we are absolutely sure about who can come to the finals, we will publish the list of the finalists.

We’d like to share some information from the organizing committee headquarters. The finals’ participants will be accommodated in the beautiful Kempinski hotel in the centre of St. Petersburg, on the bank of the Moika. The hotel is located within a walking distance from the Vkontakte office, so there won’t be any exhausting buses and coming across the city’s traffic jams! Please note the roof restaurant with the view on the Palace Square when you take a look at the photos of the hotel.

There is no exact timetable yet, something depends on the time when the participants will arrive and the complexity of the problems (that’s right, the final round may not have the usual timing). The general plan is as follows:

• July, 13: Checking in, having dinner, meeting each other and having fun.
• July, 14: Most of the day will be dedicated to an unofficial entertaining event called Code Game Challenge (special for VK Cup 2012). Also a short testing tour is planned on that day. In the evening the great dinner will be topped with Code Game Challenge Show – watching the strategy tournament on a large screen.
• July, 15: The main day of the competitions (good luck!). In the evening we’ll reward the winners and celebrate all finalists (I am sure that everyone will be pleased :));
• July, 16: Going home.

Vkontakte and Codeforces are very glad to see the students’ interest in VK Cup 2012. Despite us inviting only young coders to the championship (the age limit should not exceed 23 years), nearly 6000 participants registered there. They geographically cover practically all countries of the world! We are very glad to see that almost all coders who advanced to the finals could make it to St. Petersburg. The winners will get worthy awards, and at this point we are happy to announce that the championship prize fund has been increased! You’ve got an aim to fight for and do your best to win!

• 1st place — $20000
• 2nd place — $10000
• 3rd place — $5000
• 4-5th place — $2000;
• 6-10th place — $1000.

Easy journey to the finalists,
The VK Cup 2012 jury and organizing committee.

Questions and Answers

• What will be the rules of the Final Round? The round will be held by the rules of Codeforces, it will be 2 or 2.5 hours long. The dynamic problems' scoring is likely to be used.
• Will we use the PCs that you will give us, or our own PCs? The participants will use special workstations prepared by the VK Cup Team. It is not allowed to use one's own laptops. You may bring a USB-keyboard, but it should not have superior features.
• What operation system will be used? We hope to give the oppotunity to boot Ubuntu 12.04 or Windows at the participant's choice. We are working on it now. We will install a wide list of free software on both OS.
• Is it possible to use a prewritten code? Basically no, it is only allowed to use the code written on the competition. But you may use the code written on the practice session or on the CodeGame coding phase.

Saint-Petersburg photos

The first information letter

General information

In the first part of August 2012 Saratov State University runs an international student summer school in computer programming. The exact dates are 1-11 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 — Russian.

The fees are 16000 RUR (~ 510 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://acm.sgu.ru/sazanka-2012/ till 15th June 2012. 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.

About Saratov State University

Saratov State University, regularly achieves significant advances in programming competitions. The following are the main achievements of the university in international competitions:

• 2002 ACM-ICPC World Finals silver medals, Europian Champions
• 2003 ACM-ICPC World Finals silver medals
• 2006 ACM-ICPC World Finals golden medals, Europian Champions, World Champions
• 2007 ACM-ICPC World Finals silver medals
• 2008 NEERC Champions
• 2009 ACM-ICPC World Finals golden medals
• 2010 ACM-ICPC World Finals silver medals
• 2011 ACM-ICPC World Finals silver medals

Mike Mirzayanov,
Saratov State University