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.

Hello everybody!

Today, Codeforces Round #137 for the Second Division Participants will take place. As usual, all other interested persons can take part in it.

The problems have been developed by a group of authors from Vladivostok: Ilya Zban (izban), Alexey Evsyukov (aevsyukov), Zakhar Voit (zakharvoit).

Gerald Agapov (Gerald) has greatly contributed as well and we thank him for it. The translation of the problems has been done by Maria Belova (Delinur) — thanks to her! We are also grateful to Pavel Kunyavskiy (PavelKunyavskiy), who has help us in the preparation of the contest.

We hope you will have fun and like this round. The points distribution will be standard (500 — 1000 — 1500 — 2000 — 2500).

Good luck to everybody!

UPD: The start will be 15 minutes later due to technical reasons, we apologize.

UPD2: Congratulation to winners!

In second division:

1: zxl0714

2: resodo

3: mugurelionut

4: hmspmy077

5: CCC

6: white_rich_beautiful

7: loveSakura

8: gcwtft827

9: yuxingdubai

10: b821213

In first division:

1: navi

2: Shik

3: SteamTurbine

UPD3: The editorial is published.

For the first time, the traditional "Izhevsk Training Camp" will be held simultaneously in Izhevsk and Yevpatoria (Ukraine).

Please find attached the newsletter and the camp schedule as well as the translated newsletter in English. Please note that the trasnlation is unofficial and is provided for reference only.

Newsletter (rus)
Newsletter (eng)
Camp schedule (rus)

Tomorrow, in 4 and half hours before the end of the summer (check your zone), Codeforces Round #136 will take place. I am the author of this round, it's my 6th contest on CF.

Gerlad Agapov (Gerald) is helping me in preparing the problems. Translations will be done by Maria Belova (Delinur). Thanks to them.

I hope you will like this round. The points distribution will be standart.

Thanks!

7 user in the first division solved all 5 problems, here they are:

1. peter50216
2. yeputons
3. winger
4. rng_58
5. RAD
6. al13n
7. KADR

Meanwhile, in second division, Top-4 looks like this:

1. blue.boy
2. de_troit
3. lxyxynt
4. ilona

You can find the editorial of the contest here.

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!

Welcome to Codeforces Round #134!

After over two years, it is again my great pleasure to be the main problemsetter of a contest on Codeforces. Thanks a lot to Gerald for helping me organize the round. I hope you will enjoy solving the problems as much as we enjoyed preparing them for you.

Dynamic scoring will be used, but the problems will be ordered by their expected difficulty, from easiest to hardest. Are our predictions correct? I am eager to see. :-)

Good luck!

Update: The contest is over! Here are the results:

First division:

1. rng_58

2. panyuchao

   pieguy

3. tourist

4. Petr

5. ACRush

6. Zhukov_Dmitry

All contestants from the top seven solved three problems. Note that there was a tie for second place. :-)

Second division

1. dsbuaa

2. hqztrue

3. Gullesnuffs

In second division, seventeen contestants solved four problems. Nobody managed to crack E; it was also present in the first division as problem C, and proved tricky even for the experienced competitors.

Congratulations to the winners!