Good day for all!

I invite you to participiate in the round 194. I'm author of it. It is my fourth round, but three previous ones were a long time ago: Codeforces Beta Round 79 (Div. 1 Only), Codeforces Beta Round 94 (Div. 1 Only), Codeforces Round 110 (Div. 1) (I apologize to the div-2 participants that I have mention only div-1 round, but even one link looks bulky).

This time you will help to boy Gerald cope with his problems as in the Codeforces Beta Round 79 (Div. 1 Only). This time his problems are so serious that he became coordinator of contests on the Codeforces, to be able to throw his problems to you.

I want to thank Gerald for he is great as coordinator. When you are work with him you are fill the everythink is under control. Moreover I want to thank Maria Belova for translation problems statements to the English.

This round will be held in unusual time — 12:30 Moscow Time.

Score distribution is standart: 500 — 1000 — 1500 — 2000 — 2500.

Thanks everyone for participation, welcom to editoral.

Congratulations to winners:
Division 1:
1. KADR
2. RAVEman
3. PavelKunyavskiy
4. Dmitry_Egorov
5. RAD
6. sy2006
7. mmaxio
8. riadwaw
9. niyaznigmatul
10. RomaWhite

Separate note two Ukrainian participiants, who only solve all five problems!

Division 2:
1. IMOiguanas
2. savsmail
3. suyash666
4. AntiForest
5. kang205
6. jschnei
7. littlepanda
8. langdamao
9. 9mmlitswe
10. Renkai

Rah-rah!

We are moving forward to accelerate testing. In fact, when our rounds attract 3500+ registrations, it is hard to test all the submissions on nine computers "Core 2 Duo E6750, 2.66 Ghz, 3Gb".

Computer Science Department of Saratov State U has recently got 20 new computers i5-3470, 8Gb. After a little research it was found that if boost CPU to 3.5Ghz (of course, turning off all sorts of turbo boost and after many hours of stability check), the speed is approximately equal to twice the speed of the old testing machines. This is very convenient as it will in future only to divide all the time constraints in the problems by 2.

We have moved to testing on new computers and we do it in compatibility mode. This means that all the time constraints before the start of the program are divided into 2, the program is executed, and at the end a running time is multiplied by 2. In fact, if you do not use the cut-off by time or some other unsavory stunts, you will not detect any changes.

Old testing machines are switched off now.

To be very precise, the new computers are not so fast as 2x old. That is in compatibility mode it is normal to notice a slight degradation in speed.

Hello everyone!

In several days (July 24, 19:30 MSK) will take place Codeforces Round #193 (Div. 2), which I have prepared. Those who has already reached the first division traditionally can participate in the round out of the competition.

I would like to thank Vitaliy Gridnev (gridnevvvit), Pavel Kunyavskiy (PavelKunyavskiy) and Dmitriy Ivanov (DmitriyIvanov) for testing of problemset, coordinator of Codeforces rounds Gerald Agapov (Gerald) for useful hints and Maria Belova (Delinur) for translation of statements into English.

Good luck and high rating to all!

UPD1. The score distribution in this round will be dynamic (see here). In our opinion problems are sorted according to their difficulty.

UPD2. Analysis of problems is publisched.

UPD3. Rating is updated. Congrutalations to the winners who solved 4 problems:

Williamacm

Windseeker

Tifuera

seen

UPD: Editorial

Hello!

After the barrage of non-standard contests (memSQL, ABBYY, Yandex), we present you a standard and fun (and strange) Codeforces round! This contest is prepared by Indonesian coders: fushar, jonathanirvings, and me (dolphinigle)! fushar wrote D2-E/D1-C, jonathanirvings wrote D2-B, and I wrote the rest. For me, this is my fourth contest, after Codeforces Beta Round 87 (Div. 1 Only), Croc Champ 2012 - Final, and last week’s MemSQL start[c]up Round 1 (only 1 problem there though). We would also like to thank Gerald for helping with the contest preparation, Delinur for translation, and MikeMirzayanov for the system!

I think this contest is stranger than usual -- The statements are strange, there are pictures everywhere, etc. There is a single problem with very lengthy statement (I am unable to shorten it further without losing clarity, I'm sorry), but I think it's very clear. The other problems have relatively short statements.

fushar drops a message for you:

We think that the solutions to all problems are satisfying to discover. We want to add a special note: you might find that the solutions will not be too “usual” :).

Happy solving!

UPD: The contest is finished! Editorial will be posted tomorrow by fushar. Hope you enjoyed the contest!

...Div1-D 329D - The Evil Temple and the Moving Rocks was a little too strange I guess.

UPD: Congratulations to the winners!

D1:

1. espr1t

2. RAVEman

3. Psyho

4. Petr

5. Shik

D2:

1. RNS_MHB

2. Parsa.pordel

3. s0en1it

4. RaJin

5. darrenhp

You guys are certainly good at ad hoc problems! :)

UPD: Komaki, followed by Marcin_smu finally solved the last problem 329E - Evil after the contest. During the contest, they submitted some solutions with the right idea but got caught by pretest. You guys are awesome!

ABBYY Cup 3.0 — Finals is about to begin. We wish good luck to all the participants!

You may view the current contest standings here.

We do not want the rest to get bored. So ABBYY and Codeforces conduct an unofficial online version of the contest today at 15:30 UTC.

This round will be:

• rated
• for both Div.1 and Div.2
• 2 hours duration
• on the modified ACM ICPC rules (problems are divided into subproblems, count only complete solutions of subproblems, there is a score for each subproblem, a penalty is charged by the rules of ACM ICPC)

Good luck!

Hi!

The next stage will consist of three elimination rounds that will be held on:

Online round 1 — 14 Jul 2013, 21:00 MSK; Materials; Analysis

Online round 2 — 18 Jul 2013, 13:00 MSK; Materials

Online round 3 — 22 Jul 2013, 05:00 MSK; Materials

Each contest round lasts 100 minutes. Links to the rounds are avaliable on the round names above.

The scoring model for this stage will be Grand Prix 30.

To advance to the final round in St. Petersburg, Russia, you don't have to participate in all online rounds. You will need to place within one of these groups:

*top 4 in one of three rounds among contestants who have not yet advanced to the final round;

*top 9 in the cumulative results of two out of three rounds among contestants who have not yet advanced to the final round; or

*top 4 in the cumulative results of three rounds among contestants who have not yet advanced to the final round,

All finalists, another 75 best participants of elimination stage and another 75 random participants of the elimination stage, who will solve at least one problem will get a T-shirt!

You can always read the full schedule and regulations on the official website.

Good luck! Next stop: Saint Petersburg!

UPD: Results of the online round 1 are now official and we congratulate Kenny_HORROR for impressive victory using "all open" strategy.

First finalists are: Kenny_HORROR, Petr, tourist, eatmore.

UPD2: Congratulations to tourist for the online round 2 victory. We are glad to invite vepifanov, yeputons, ivan.popelyshev, peter50216 to the final round!

UPD3: Based on their scores in round 3, winger, KADR, ainu7, s-quark are invited to the final round. Congratulations!

Rightful place among finalists goes to

based on two out of three elimination stage rounds : burunduk3, misof, niyaznigmatul, cerealguy, Mimino, liympanda, romanandreev, watashi, RAVEman;

for the overall performance in the stage: Nerevar, ilyakor, dreamoon_love_AA, pparys.

Dear finalists! Congratulations and see you soon in St. Petersburg. I will contact you shortly on the matter of your final round participation. Please, do not ignore my emails and answer promptly =)

UPD4 Materials of the second test round are published: Test round 2; Materials

Hello everyone!

The first round of start[c]up is upon us. It is open to all participants. Registration works as a normal CodeForces round, and will close five minutes before the start of the contest.

The contest uses normal Codeforces rules, and will be rated. The score distribution is 500-1000-2000-2000-2500.

The problem set has been developed by MemSQL engineers pieguy, nika, exod40, SkidanovAlex and dolphinigle.

Top 500 competitors will advance to the second round, with the top 25 Silicon Valley residents invited to participate on-site, where there will be special prizes.

Good luck and happy coding!

UPDATE: Please note that the score distribution has changed.

UPDATE: Editorial is up now!

Hi!

Qualification round of the Yandex.Algorithm competition that will start on July 8, 2013, at 7 p.m. This round is virtual, so you need to start your qualification within 24 hours from the beginning of the qualification round. Qualification will last 100 minutes even if you will start at 6:59 p.m. Please, do not discuss the problems until 8:40 p.m. July 9 — someone can be still solving the problems.

The 2,000 best contestants who have solved at least one problem will advance to the elimination stage. Already advanced from test round participants will have a chance to work with the TCM/Time.

Good luck! Almost 200 t-shirts and more than half a million rubles are waiting for you!

Registration

Link to the contest

UPD: Archive is at the competition site.

There were a lot of requests like "Russian team ioi-2013 blog". I'll try to write something. This year I am a guest on IOI, so I have a schedule that differs from the contestants' one. For example, when the contestants had the Practice Session, where, as rumoured, there were something bad with printers (but do you remember at least one place where printers worked good from the beginning? ;), I had an excursion to Lone Pine Koala Sanctuary, where are some beautiful Australian (but not only) animals, for example the following ones:

Welcome to another Codeforces Round!

Please note that the time of round #191 was changed. Contest will start at Thursday 12:30 UTC.

My name is Linh (ll931110). I'm from Vietnam, and I'm glad to present to you my first Codeforces round. It is for Div 2 only; however, I welcome participants from Div. 1 to participate and enjoy challenging problems. I hope this would be a pleasant gift for those who are going to IOI 2013 (and participants from World Finals), which will take place in just a couple of days.

This round is prepared by me and fchirica (from Romania). Also, I would like to thank the Codeforces team who puts efforts on making Codeforces and Polygon possible.

Happy solving!

UPD1: The score of problems in this round will be dynamic. The problems will be sorted in increasing difficulty order, at least in our perspective.

UPD2: The contest is over! Congratulations for everybody, especially for those who solved E. You proved to be smarter than I am (your solutions were totally unexpected to us). Thank Gerald, Aksenov239 and Delinur for helping us on preparing the round!

Div. 2 winners:

1. SillyHook02

2. Tsukiko

3. Quit_Quickly

4. Zhengxu

5. sevenzplus

Those are five people who nail all problems!

Unofficial winners:

1. Kissshot

2. R_R_

3. xchernoff

4. wakaka

5. phtniit

The editorial will be completed soon after revising and adding possible alternative solutions. You are welcome to post your answers in comments.

Thank you and see you in the next round!

UPD3: Editorial is now available. Remind that it is not the final version, as we are writing possible alternative solutions for problems. Stay tuned!

UPD4: Editorial is now completed.