I will be hosting Petr Mitrichev Contest 10 this Saturday (October 27) between 15:30 and 20:30 Moscow time (other timezones: http://timeanddate.com/worldclock/fixedtime.html?msg=Petr+Mitrichev+Contest+10&iso=20121027T1530&p1=166&ah=5 ).

The contest will be held at http://codeforces.net/gyms . Both teams and individual participants can join. The contest itself will be at http://codeforces.net/gym/100110 , but this link will be accessible only after the start of the contest.

There will be 10 problems of varying difficulty (most are quite difficult) for 5 hours. Your solution needs to be correct on all test cases to be accepted (the standard ACM ICPC rules). People will be ranked by the number of solved problems, and by total penalty time in case they're tied on solved problems, so don't be late! :) Note that in each problem you need to read the input from a file and write the output to another file — so don't read from stdin and don't write to stdout! Problem statements will be in English.

Feel free to ask any questions that you might have, and also please tell if there are any issues with the contest system — it's the first time I'm using codeforces.com/gyms .

Registration: http://codeforces.net/gymRegistration/100110

5 minutes before start, good luck everyone!

Solution ideas: http://petr-mitrichev.blogspot.com/2012/10/petr-mitrichev-contest-10-solution-ideas.html

Hi!

A few hours later you're lucky to participate in Codeforces Round #147 for Div.2 participants, but traditionally the others can take part out of the competition. It has been prepared by me (NALP), Igor Kudryashov (Igor_Kudryashov), Pavlik Holkin (HolkinPV), Gerald Agapov (Gerald), Mary Belova (Delinur) and Mike Mirzayanov (MikeMirzayanov).

Traditionally I wish good luck, accepted solutions and successful hacking attempts for you!

The standart scoring system will be used: 500-1000-1500-2000-2500

UPD: The contest has ended, congratulations to the winners:

1. try_skycn

2. AntiKismet

3. dianbei_03

4. Uncia

5. Bigsophie

Hi!

Codeforces Round #146 is going to be here soon. Round is prepared by YuukaKazami, MinakoKojima. I write problems for Div I and MinakoKojima write for Div II. Gerald did a great job in coordinating round preparing, and he also give some pretty good advise about problems. I'd like to express my gratitude to him. Traditionally thanks to Michael Mirzayanov (MikeMirzayanov) for perfect Codeforces system and Polygon system as well and Mary Belova (Delinur) for translating problems. Also thanks to donehl for testing the problems and making his comments about the problems.

Score distribution is 500-1000-1500-2000-2500 in both divisions.

Hope you enjoy the problems! =)

I apologize for the 10 minutes delay.I'm very sorry for the inconvenience I caused. So I'm writing a good editorial for compensation :)

The Editorial is here: Editorial

Congrats to winners!

Div1:

1.rng_58

2.Dmitry_Egorov

3.bjin

4.Petr

5.Egor

6.tourist

Div2:

1.RiKang

2.Caesar11

3.Gabaum

4.ilona

5.Bidhan

6.sm_hossein

Good day, Codeforces!

I can't wait to give you a good news that a new competition for div1 participants is appeared in the list of events. This competition is a broadcast of the Saratov Team Olympiad on Programming and therefore will be held by the ACM-ICPC rules. Especially for div1 participants, we complicate this school competition a bit, so that everyone was interested to solve the problems.

This Competition is individual, it will be rated for both divisions.

Please note that the start time of the competition is different from the usual. Also note the unusual length of the competition.

See you at Codeforces Round #145! I hope that everyone will find the time to participate in the competition.

UPD. The competition finished, the editorial will come soon.

Hi all!

Codeforces round #144 is going to be today.

Round is prepared by: KAN, fdoer, Skird, tunyash. Special thanks to Gerald for coordinating round preparing, many awesome ideas and making statements easy-understandable. Also I thank MikeMirzayanov for enjoyable problem-preparing system, Delinur for statements translation.

I hope, that all will be well and you will enjoy solving problems.

Good luck!

UPD: Score distribution will be announced a few minutes before the start of the contest.

UPD2: score distribution is 500-1000-1500-2000-2500 in both divisions

UPD3:

Congrats to winners.

div1:

1. tourist
2. rng_58
3. Mimino
4. Dmitry_Egorov, Egor

div2:

1. debug22
2. ryz
3. dvdreddy
4. vinodreddy
5. rdivyanshu

UPD: editoral for all problems, except div1.D is ready

Hi to all!)

Codeforces #143 for participants from second division is going to be today. I think, it is not necessary to remind, that coders with rating greater than 1699 will be able to take part out of the competition.

Problems' autors for this event are Kholkin Pavel (HolkinPV) and Kuznetsov Nikolay (NALP). Kudryashov Igor Igor_Kudryashov and Agapov Gerald (Gerald) helped in contest's preparation too. Special thanks to creator great resource Codeforces Mike Mirzayanov (MikeMirzayanov) and our translator Maria Belova (Delinur).

Score distribution will be determine later, monitor for changes).

We wish you enjoy participating this competition and want you to get something new and useful.

UPD: Score distribution will be standart 500-1000-1500-2000-2500.

UPD2: Round is over. Thanks to all for participating. Six first coders solved all 5 problems, congratulations.

1) teoy

2) gomineral02

3) mrNobody

4) Ryannnnnnn

5) marschenly

6) KuchumovIlya

Editorial will be published soon.

UPD3: Editorial is published, you can find it here

Good afternoon.

Today I want to share with the public my little project (which was part of my thesis), service on the "defrost" the results of the competition format ACM ICPC — "System for Right Solutions Standings Dancing" (S4RiS StanD). Hosted on github.

Introduction

In 2011, my team is still held in the semifinals, where at the close I saw the live operation of such a system ITMO. The feeling was strong. But after analyzing the work and reviewing captured my video, I realized that it is possible to improve this implementation, make it open to and more modest, local competitions, the participants were able to watch in awe tabulation of results. It was chosen as part of my thesis was used already in one competition and received a logical extension.

Hello everyone!

Codeforces Round #142 will be held today at 19:30 in Moscow time, and it will take place in both divisions.

The authors of the problems are me, Evgeny Vihrov (gen), and Andrey Vihrov (andreyv). Both of us are students of the Faculty of Computing in the University of Latvia. This is our very first contest on Codeforces!

Big thanks for the help in preparing the contest go to Gerald Agapov (Gerald), and to Maria Belova (Delinur) — for translating the problem statements in English. Also thanks to Mikhail Mirzayanov (MikeMirzayanov) for the Polygon system, which we found to be great for preparing contest problems.

We hope that each participant will be able find a problem to match his taste. Please, consider reading all the problems!

We wish you an exciting round!

UPD1: The score distribution will be dynamic. The problems will be sorted in order of expected increasing difficulty.

UPD2: Due to the technical problems the contest was extended by 5 minutes. We are sorry for the inconvinience.

UPD3: The analysis of the contest is available. Enjoy!

The round is over! 5 contestants solved all the problems in division 1, and in division 2 only the top four contestants solved all the tasks. Congratulations to the winners!

Div I

1. YuukaKazami
2. peter50216
3. kelvin
4. takaramono
5. Martin

Div II

1. coquelicot
2. llj_bash
3. kb.
4. niukuo
5. Petar

Hello!

We're glad to say that at 3.00 PM, October 6 another contest by team Samara SAU Teddy Bears will be held.

This contest was a qualification round for Samara SAU teams. Winners will participate in ACM ICPC 2012-2013. Contest will be easy, a bit easier than our previous contest.

Contest is over. Thanks to coders who participate in it. Now you can start virtual contest (registration by this link), or just solve the problems.

What else:

• Input-output: standard console input-output (like at Codeforces rounds)

• It's not recommended to use %lld for reading and writing 64-bit integers in GNU C++

Welcome, friends)

We are glad to introduce you regular Codeforces round #141 for Div.2 participants. But traditionally the others can take part out of the competition.

Problems are prepared by command of authors: Pavel Kholkin (HolkinPV), Ivan Fefer (Fefer_Ivan), Igor Kudryashov (Igor_Kudryashov) and Gerald Agapov (Gerald). Traditionally thanks to Michael Mirzayanov (MikeMirzayanov) for perfect Codeforces system and Mary Belova (Delinur) for translating problems.

Score distribution is standard.

We wish you good luck, successful hacks and high rating!

UPD: the contest is over, hope you enjoy it) Congratulations to winners:

1) AntiFate

2) alicechennan

3) honeyofsistercha

4) Fride

5) bla_bla_bla

UPD2: the editorial was already published, you can find it here