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

Hello everyone!

Today, at 19:30 MSK Codeforces Round #140 will take place. The competition will be held in both divisions.

I'am the author of today's competition. My name is Ilya Malinovsky, I'm student of Saint-Petersburg State University. This is my first Codeforces round.

I want to express my gratitude to Gerald Agapov (Gerald) for his help during the work on the round, Maria Belova (Delinur) for statements' translation from Russian into English, Mikhail Mirzayanov (MikeMirzayanov) for the possibility to prerare contests (and, of course, to compete in them) here, on Codeforces.

As usual, in most of the problems participants will help different characters to cope with their troubles and misfortunes. You will have only two hours to help epical hero, an alien, noble knight and other characters. Also, insidious stone heaps will resist you in one of the problems...

I hope, most of participants will enjoy the tasks.

Good luck!

P.S. Information about score distribution will appear not long before the round starts.

upd. Score distribution is stadart (500-1000-1500-2000-2500) in both divisions.

upd 2 Round is over!

Congratulations for winners!

div1:

1. peter50216

2. Dmitry_Egorov

3. Egor

4. RAVEman

5. bmerry

Winners have from 3 to 4 solved problems. Noone managed to solve E.

div2:

1. Velicue (he is the only div2-participant, who got 5 "OK"s)

2. Frommi

3. Aerolight

4. Shahriar_sust

5. bzdbz

Thanks to everyone for participating! I hope, you've enjoeyd the round.

Full editorial.

Hello everyone!

That is Codeforces Round 139 for the second division only. Members of the first division can participate out of competition.

Round is prepared by Ripatti , Gerald , Delinur.

We will use dynamic score system. Problems will be ordered in order of expected increasing difficulty.

Good luck!

UPD. For technical reasons round delays in 15 minutes.

UPD2. Testing is complete. Winners:
1. wccy
2. ttl
3. shubhanshu
4. Atarashi_Ako
5. dvylfz921

2 members solved all 5 problems.

English editorial will be tomorrow. You can try to understand russian editorial.

UPD3. English editorial.

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 everybody!

I am glad to announce that Codeforces Round #138 will be held today at 19:30 MSK. I (Vasiliy Vadimov) am the author of this round. It is my first Codeforces round, I just helped other authors to prepare their rounds before.

I would like to thank Gerald Gerald Agapov for his help in the preparing of the round and Maria Delinur Belova for translation of the problems' statements in English. Also I am grateful to Mike MikeMirzayanov Mirzayanov for such an excellent contest system as Codeforces.

Good luck! I hope you will be interested in the problems.

The point distribution is standard in both divisions (500-1000-1500-2000-2500).

UPD. Attention! D language will not be available on this contest.

UPD2. The round is over, top-5 in both divisions:

Div1:

1. Petr
   
2. tourist
   
3. peter50216
   
4. Shik
   
5. Egor
   

Div2:

1. ecnerwala
   
2. ordcoder
   
3. scipianus
   
4. jonathanpaulson
   
5. void_rank
   

Congratulations to the winners!

Also I am apologising for mistakes in statement of problem div1 A/div2 C. The tutorial will be published tomorrow.

UPD3. The tutorial is available here.