Soon you are lucky to participate in Codeforces Round #284, and problems have been prepared by Vitaly Gridnev (gridnevvvit), Ilya Los (IlyaLos), Danil Sagunov (danilka.pro).

We want to thank Max Akhmedov (Zlobober) for help with preparation of this round, Maria Belova (Delinur) for translation of statements and Mike Mirzayanov (MikeMirzayanov) for marvelous Codeforces and Polygon systems.

Scoring system will be dynamic. Problems will be arranged in ascending expected difficulty order.

Round finished, congratulations to winners!

Div1:

1. yeputons
2. rng_58
3. Endagorion
4. KADR
5. Egor
6. uwi
7. mmaxio
8. atetubou
9. RAVEman

Div2:

1. sorry_dreamoon
2. dreamoon_love_AA
3. dreamoon_fan

Editorial

Good luck!

Доброго времени суток, уважаемые пользователи Codeforces!

Хочу ещё раз обратить внимание всех потенциально заинтересованных участников на такое мероприятие как Открытая всероссийская олимпиада школьников. Напоминаю я не просто так, а по отличному поводу — сегодня там появились три новые задачи, а в ближайшие дни ожидаются ещё две. Задачи подготовлены жюри московских олимпиад, мы честно старались сделать их интересными и разнообразными.

Если кто-то пропустил начало олимпиады, то в этом нет ничего страшного, до конца ещё целый месяц, вполне достаточно, чтобы сдать все предложенные задачи. Время сдачи никак не влияет на положение в таблице. Лучшие X участников будут приглашены поучаствовать в очном финале, для которого задачи отбираются с ещё большей любовью и заботой, так что не упустите свой шанс.

Для тех, кто руководствуется более приземлёнными соображениями, чем качество задач, дополнительно сообщаю, что заключительный этап традиционно имеет первый уровень, а значит призеры и победители могут получить льготы при поступлении в вуз в соответствии с порядком приема в вузы.

Призеры отборочного этапа олимпиады никаких льгот не имеют — поступить не выходя из дома всё-таки не получится.

Более подробную информацию об олимпиаде вы можете найти по приведённой выше ссылке. Любые оставшиеся вопросы смело задавайте в комментариях.

P.S. Тех, кто будет в комментариях обсуждать решения задач, ждёт справедливое возмездие и отрицательная карма!

UPD: добавлены две новые задачи, больше задачи добавляться не будут.

UPD2: Почти наверное традиционного продления олимпиады не будет. Планируется пригласить порядка 400 участников. Обратите внимание, сейчас для попадания в топ-400 требуется набрать совсем немного баллов. Жюри рекомендует прочитать все задачи — почти в каждой имеются простые группы с немалым количеством баллов.

Hi, Codeforces.

We have put 2014 ACM-ICPC Xi'an Regional Contest, one of this year's Chinese regional contest in Codeforces Gym.

The 2014 ACM-ICPC Asia Xi‘an Regional Contest (2014) takes place on 25 Oct 2014 — 26 Oct 2014 in Xi'an, China. The problem set was prepared by Fudan University.

Standings are translated to English by matching their team names and their registration info on ICPC official website. For those schools which didn't register on ICPC official website, I have manually "translated" (in fact, Google and Copy & Paste) their school name to English. Inform me if you found any mistake.

Problem G has slightly looser time limit than onsite contest: alternative solutions run way slower on Codeforces, while model solution runs way faster.

Thank MikeMirzayanov and Fefer_Ivan for the Codeforces Gym platform!

Hi, Codeforces.

Today, on December 17 at 19:30 MSK regular, 283-rd Codeforces round will take place. Problems are authored by me, Mikhail Tikhomirov. Maxim Akhmedov (Zlobober) helped me with discussing and preparing the problemset, Maria Belova (Delinur) translated problem statements in English, and Georgy Chebanov (gchebanov), Alexander Mashrabov (map) and Niyaz Nigmatullin (niyaznigmatul) tested the round and helped us with finding bugs and mistakes; let's give them a round of applause!

The round will be for both divisions. The scoring is standard (not dynamic); score distribution is as follows:

Div. 1: 750-1250-1250-2000-2500

Div. 2: 500-1000-1750-2250-2250

This is going to be my fourth round at Codeforces. I really hope it will go as good as three before it. =) Wish you all the best of luck!

UPD: the round is over, thanks for participating!

Grats to the winners:

Div. 1:

1. SirShokoladina

2. Petr

3. rowdark

4. anta

5. Marcin_smu

6. Merkurev

7. qwer1561

8. Ra16bit

9. kuviman

10. Um_nik

Div. 2:

1. SergeyMelnikov

2. sepehr103

3. StarCuriosity

4. dotato

5. husheyn

Editorial is here ( UPD: now in English!).

The contest is in gym now.

The 2014 ACM-ICPC Asia Mudanjiang Regional Contest takes place on 11 Oct 2014 — 12 Oct 2014 in Mudanjiang, China. There are 11 problems in this contest. The problem set was prepared by Zhejiang Univesity. These problems also can be found at http://acm.zju.edu.cn (Problem 3819-3829).

The official results can be found at this page. Congratulations to Jilin Unversity to win the contest!

In the contest, problem A, C, D and F is written by Archon.JK, B is written by yxdb and navi, E and I is written by me(ZhouYuChen), G and J is written by zimpha, H is written by chnluyi, and K is written by prowindy. Bobgy, Flandre_Scarlet, fancy, NeverLand.Dai and -.- also tested or discussed the problems.

Thank MikeMirzayanov for helping us migrating the problems to Codeforces!

Any suggestions or feedback is welcome.

Hi,

Codeforces Round #282 will be held at 13th of December, 19:30 MSK. Please don't note anything since the time is the usual time of contests.

The round is prepared by FarbodY, Haghani and Me(matrix).

We'd like to thank Zlobober who helped us a LOT for preparing the problems, MikeMirzayanov for the Polygon and Codeforces platforms and Delinur for helping us in preparing statements and translating them.

Our special thanks goes to mruxim for testing the round.

The problems will be sorted according to the estimated order of difficulty according to our opinion but we strongly recommend you to read all of the problems.

As always the update regarding score distribution will be posted just before the round starts. :)

UPD: It was written that contest starts at 20:00 MSK. it was a mistake and is fixed now. The round starts at usual time 19:30 MSK.

UPD2: We also thank niyaznigmatul for testing our round.

UPD3: Score distribution:

Div1: 500-1000-1750-1750-2500

Div2: 500-1000-1500-2000-2750

As you might have noticed, the scores can now be multiples of 250 as well. Let's thank Codeforces team for adding this feature!

Good luck and Have fun!

UPD4: Congratulations to the winners of both divisions:

Div1:

1. tourist
2. winger
3. sankear
4. uwi
5. Egor

Div2:

1. Ginger88895
2. pwild
3. arthurpd
4. konmaj
5. ezkatka

The editorial for all problems except D and E Div1 are ready and can be found here. It'll be completed soon.

We thank you all for participating and hope you had a good time.

UPD5: The editorial is now complete and can be found here.

Hi!

On 3rd December, 18:00 at Moscow will be Codeforces Round #281 (Div. 2). As usual Div. 1 contestants can take part out of contest.

This is my first Codeforces Round and I hope that this isn't the last one :)

Thanks to Maksim Akhmedov (Zlobober) for the help in making contest and MikeMirzayanov for Codeforces and Polygon platforms.

UPD1: The scoring will be dynamic.

UPD2: Contest is over. Thank to all participants. I hope you liked my contest.

UPD3: Editorial

UPD4 Top-5 contestants, congrats

1. ShiXingxing15

2. ganar27

3. Tim_LinYd

4. coolwyj

5. gaoyihan

Also congrats to gaoyihan, who solved problem E.

UPD5 Hack stats by kostka.

Greetings to the Codeforces community!

Regular Codeforces round #280 for participants from the second division will take place on 1 December, 19:30 MSK. Participants from the first division are able to participate out of the contest.

It is my first round on Codeforces. Hope you will enjoy this round.

I want to thank Max Akhmedov (Zlobober) for help with preparation of this round, Maria Belova (Delinur) for translation of statements and Mike Mirzayanov (MikeMirzayanov) for great Codeforces and Polygon systems.

Participants will be given five problems and two hours to solve these problems.

UPD: Scoring is standard — 500-1000-1500-2000-2500.

UPD: Thanks to everyone, who participated in the round!

Congratulations to the winners:

1.alex_y

2.wingemerald

3.Eric94

4.Zpw987

5.rabbit_TR

standings

UPD: Editorial is here.