UPD: The contest platform is up! Everyone can now register through the platform!!!!

UPD: The champion will be invited as a guest (with full accommodation and travel expense covered) to the 2026 Universal Cup Finals. The champion will be awarded at the time and will be invited to participate in the onsite challenge.

Hello Codeforces! We are very happy to announce that, after months of preparation, we have finally scheduled our first online challenge from December 17th to December 24th! Sponsored by Huawei, we have prepared valuable prizes for everyone to compete for! Although many details are still to be finalized, we are too excited to share the following details with you as an early Christmas gift!

• Contest Name (Subject to Change): The 2025 Universal Cup Online Challenge Sponsored by Huawei

• Platform: Universal Cup Challenge Platform (Powered by Hydro）

• Date: December 17th &mdash 20:00; December 24th 20:00（UTC+8)

• Prize:

As always, the Universal Cup is dedicated to bridging the gap between the competitive programming community and the industry. This online challenge is an attempt that we are counting on. We will do our best to make it as good as possible, and we call on everyone to support this challenge by participating!

Since we hope everyone to focus on the challenge, there will be no regular stage on December 21st. The registration details will be announced in early December. We will be posting another blog (on Codeforces, the Official Website, and other threads) to specify the rules. Please stay tuned!

To learn more about Universal Cup, please visit our official website. The 4th season is ongoing now.

The Universal Cup is sponsored by

Good day Codeforces ✨

We are excited to invite you all to Codeforces Round 1067 (Div. 2), starting at Nov/29/2025 17:35 (Moscow time).

This round features 6 problems to be scored in 2 hours, with a few problems including multiple parts. All tasks were authored and prepared by koderkushy and me. This round will be rated for all participants with rating below 2100. Take a look at all the problems, we hope you enjoy the challenge! 🚀

We extend many thanks to our team for helping make this round possible:

• abc864197532 for his excellent coordination.
• KAN for preliminary review.
• Testers lineup: Dominater069, dreamoon_love_AA, Fysty, amano_hina, _istil, __baozii__, IceKnight1093, CoderAnshu, Pols_Agyi_Pols, sv1shan, piyush_pransukhka, a.out, BiggestOtaku, Bucketsmith, -firefly-, satyam343, plAtEaUpUs, omsincoconut, snasibov05, homelanderrr, _helloLad, BladeRunner, deneribeiro10, Rafio, balakrishnan, UniversalAdmin
• Alexdat2000 for translation problem statements into Russian.
• MikeMirzayanov and KAN for lovely platforms Codeforces and Polygon.
• And of course, you, for taking part! 💛

Score Distribution: $$$500-1250-1500-2000-2750-(2500+1000)$$$ 🏆

UPD: Congrats to the winners!

• 🥇 StarSilk
• 🥈 Noobish_Monk
• 🥉 Mon_ster
• BurnedChicken
• ec3e9a2e8e

Kudos to antontrygubO_o for almost getting to the intended solution of F2 in contest!

UPD 2: The editorial is out.

Привет, Codeforces!

Благодаря поддержке Neapolis University Pafos, продолжается серия образовательных раундов.

В 28.11.2025 17:35 (Московское время) состоится Educational Codeforces Round 185 (Rated for Div. 2).

Этот раунд будет рейтинговым для участников с рейтингом менее 2100. Соревнование будет проводиться по немного расширенным правилам ICPC. Штраф за каждую неверную посылку до посылки, являющейся полным решением, равен 10 минутам. После окончания раунда будет период времени длительностью в 12 часов, в течение которого вы можете попробовать взломать абсолютно любое решение (в том числе свое). Причем исходный код будет предоставлен не только для чтения, но и для копирования.

Вам будет предложено 6 или 7 задач на 2 часа. Мы надеемся, что вам они покажутся интересными.

Задачи вместе со мной придумывали и готовили Адилбек adedalic Далабаев, Иван BledDest Андросов, Максим Neon Мещеряков, Роман Roms Глазов и Максим FelixArg Новоточинов. Также большое спасибо Михаилу MikeMirzayanov Мирзаянову за системы Polygon и Codeforces.

Удачи в раунде! Успешных решений!

UPD: Разбор опубликован

Всем привет!

Третья и последняя командная интернет-олимпиада в этом сезоне состоится уже в это воскресенье, 30 ноября 2025 года в 13:00 (по Московскому времени). Приглашаем вас принять в ней участие!

Как и планировалось, уровень сложности задач в последней интернет-олимпиаде будет несколько выше, чем в первых двух, поэтому мы надеемся, что олимпиада послужит неплохой тренировкой перед ВКОШП. Тем не менее, это не значит, что менее опытным участникам нет смысла принимать в ней участие: задач много, каждому найдется что порешать :)

Продолжительность олимпиады – 5 часов, в течение которых вам будет предложено от 10 до 12 задач. Не забудьте зарегистрироваться на цикл командных интернет-олимпиад в этом сезоне перед началом олимпиады. Обратите внимание, что для участия в командных олимпиадах нужно зарегистрировать именно команду. Команда может содержать от 1 до 3 человек.

Ссылка на регистрацию команд доступна из данного анонса, а также на основном сайте интернет-олимпиад. Всю дополнительную информацию, а также расписание всех предстоящих командных интернет-олимпиад можно посмотреть на той же странице.

Условия появятся на сайте в момент начала олимпиады. Тестирующая система находится по адресу pcms.itmo.ru.

Олимпиаду для вас подготовили студенты/преподаватели Университета ИТМО: Павел Скобелин (pskobx), Даниил Орешников (doreshnikov), Егор Юлин (EgorUlin), Ильдар Гайнуллин (300iq), Антон Вдовин (AVdovin), Степан Мишанин (Mistep), Иван Пашков (Kisel001), Дмитрий Ивченко (dimss) и Тимур Кузнецов (darknight_il).

Для связи с жюри можно использовать адрес электронной почты [email protected].

Удачи!

UPD — разбор задач доступен на сайте интернет-олимпиад.

Ciao, Codeforces! We're glad to invite you to take part in Codeforces Round 1066 (Div. 1 + Div. 2), which will start on Nov/23/2025 12:35 (Moscow time). You will be given 9 problems and 3 hours to solve them in both divisions. The round will share some problems with The 2025 ICPC Southwestern Europe Regional Contest (SWERC) 2025.

Note the unusual starting time.

Some of the problems might be interactive, so please read the guide for interactive problems if you are not familiar with it.

The problems were authored and prepared by KLPP and me.

We would like to thank

• Dominater069 for his 💭 💡 🎈 coordination;
• Alexdat2000 for Russian translation;
• dario2994 for VIP testing;
• Geothermal, MrBrionix, xiaowuc1, SmolBrain, awoo, Intellegent, IceKnight1093, MridulAhi, Adam_GS, A_G, Sana, Virv, ha___il, chromate00, beaten_by_ai for testing;
• {Rafi22, surgutti, Krzychuo}, {Akulyat, arzhantsev64, okwedook}, {AlperenT, izhang, Extile} for team testing;
• the SWERC judges team for judging the problems;
• MikeMirzayanov for creating Codeforces and Polygon;
• dario2994 for creating pol2dom, a tool to convert problems from the Polygon format to the SWERC format with minimal effort.

The score distribution will be announced after the onsite contest starts.

We hope you'll like the problemset!

UPD 1: The score distribution is as follows:

$$$500 + 1000 + 1500 + 1500 + 2000 + 2500 + 3000 + 3750 + 4000$$$

UPD 2: Upsolving & viewing of solutions and tests will be closed until the end of the onsite contest (13:30 UTC, 1 hour after the Codeforces round ends). Please also refrain from discussing the problems in public until that time.

UPD 3: Congratulations to the winners:

• Rank $$$1$$$ : tourist
• Rank $$$2$$$ : jiangbowen
• Rank $$$3$$$ : ksun48
• Rank $$$4$$$ : PEIMUDA
• Rank $$$5$$$ : Radewoosh (Only solve on problem I!)
• Rank $$$6$$$ : VivaciousAubergine
• Rank $$$7$$$ : qiuzx
• Rank $$$8$$$ : Rinne_qwq
• Rank $$$9$$$ : Rubikun
• Rank $$$10$$$ : maspy

UPD 4: The editorial is out.

Hello, Codeforces!

I am very excited to invite you to my second-ever contest, Codeforces Round 1065 (Div. 3), which will start on Nov/20/2025 17:35 (Moscow time)! In this contest, you will be given 2 hours and 30 minutes to solve 7 problems, two of which have been split into subtasks. The subtasks for a given problem are not necessarily placed adjacently in the problemset.

The round will be hosted by the rules of educational rounds (extended ICPC). Thus, all solutions will be judged on preliminary tests during the round, and after the round, there will be a 12-hour phase of open hacks. After the open hack phase, all accepted solutions will be rejudged on successful hacks. Also, note that there is no score distribution — rank will be determined by number of problems solved, followed by penalty; wrong submissions will incur the usual penalty of 10 minutes, following the rules of educational rounds.

As a reminder, only trusted participants of the third division will be included in the official standings table. This is a compulsory measure for combating unsporting behavior. To qualify as a trusted participant of the third division, you must:

• take part in (and solve at least one problem in) at least five rated rounds
• and not have had a rating of 1900 or higher at any moment in time.

Regardless of whether you are a trusted participant of the third division or not, if your rating is less than 1600, then the round will be rated for you (unless you register unrated).

Also, note the rule restricting the use of AI. If you are caught breaking this rule, you will be condemned to life spent in prison the basement of some unspecified Codeforces user. Said person's basement is a rather unenjoyable place to live in, so I would advise adhering to the rules.

I would like to thank the following people for helping make this round possible!

• cry for his excellent coordination;
• Vladosiya for translating the statements into Russian;
• satyam343 and Lilypad for discussing problem ideas with me;
• djm03178, satyam343, Dominater069, and Intellegent for being very important people who have contributed significantly to the round;
• Dominater069, nifeshe, Intellegent, catgirl, temporary1, Friedrich, djm03178, wuhudsm, -firefly-, efishel, Edeeva, yse, SpyrosAliv, ritam1234, chromate00, Ermiooo159, kevlu8, Argentum47, expertaq, simplelife, ByteRaider, and RJ_Parin_fr for testing;
• macaquedev for pretending to test;
• MikeMirzayanov for the incredible Codeforces and Polygon platforms;
• and most importantly of all, You for participating!

Good luck, and have fun!

UPDATE: Due to issues with Cloudflare, the round has been rescheduled for Nov/20/2025 17:35 (Moscow time).

UPDATE: Editorial

Hello, Codeforces! We're glad to invite you to take part in Codeforces Round 1064 (Div. 1) and Codeforces Round 1064 (Div. 2), which will start on Nov/16/2025 17:35 (Moscow time). You will be given 6 problems and 2 hours to solve them in both divisions.

The problems were authored and prepared by le0n and me.

We would like to thank:

• Sugar_fan for his coordination;
• Alexdat2000 for Russian translation;
• liqingyang, ZhouYuHang for providing problems that were ultimately not used;
• Tobo, _istil, zhoukangyang, wenhao801, baka24, zhaohaikun, xcyle, _RedWine_, Bossusuprem, mzen, phir., dXqwq, songhongyi, SubgraphCounting, Seg_Tree_, Brooksx, A2_Chaos, jhgfds, Crystally, Um_nik, Friedrich, qbf, sunzihang, EvenImage, Arpa, Adam_GS for testing;
• TheScrasse, Error_Yuan and others who were invited but unable to test for reasons;
• MikeMirzayanov for creating Codeforces and Polygon.

Score distribution:

• Div. 1: $$$500-1000-1500-2500-3000-4000$$$
• Div. 2: $$$500-750-1000-1500-2000-3000$$$

We hope you'll enjoy the problems!

UPD: Congratulations to top $$$5$$$ in Div. 1 and Div. 2.

Div. 1:

1. maroonrk, achieving perfect score at an astonishing 01:18:30!
2. JDScript0117, with an outstanding comeback at 01:55:46!
3. Benq
4. ksun48
5. Nachia

Div. 2:

1. __lucailie, with a final solve at 01:59:15!
2. weertyu
3. su_da
4. Axiom_
5. WangYuanyi

First solves:

Div. 1:

A: ksun48
B: Benq
C: OrangeEye
D: Benq
E: Benq
F: maroonrk

Div. 2:

A: f___off
B: Animesh--__--
C: lemmec0de
D: Doraemon-_-
E: Shakhzod_Toshpulatov
F: kyUUKoU

UPD: Editorial is out!

Hello Codeforces!

I am pleased to invite you to participate in 2025 ICPC Asia Taichung Regional Contest (Unrated, Online Mirror, ICPC Rules, Preferably Teams), which will be held on Nov/16/2025 04:50 (Moscow time). This is an online mirror contest for the 2025 ICPC Asia Taichung Regional Contest. The duration of the contest will be 5 hours and the contest is best for teams of three people. The mirror will use the ICPC format.

We have an excellent judge team (Regional Contest Director Ling-Ju Hung, Chief Judge Peter Rossmanith, baluteshih, henotrix, ToxicPie9, marmot0814, kasuistry, cthbst, leo900807, olmrgcsi, hank55663, alan8585, waynetuinfor, CindyLinz, samsam2310, ltf0501, LFsWang, Jeffrey, tmt514), outstanding task authors not from the judges (for both the preliminary contest and the regional: Jinn-Shyong Yang, Shik, smallbird, Shenghui Chen, Kuroni), and strong tester teams (nikilrselvam, Vince729, applepi216, qq11123334, LiuYun40066, SorahISA, -1e11, rgnerdplayer, 2qbingxuan) this year! The judges greatly appreciate the testers for their valuable feedback!

Last but not least, we would like to give a big shout-out and express our gratitude to MikeMirzayanov for creating the incredible Codeforces platform, and to Mike and Vladosiya for all their support in making this online mirror contest possible!

On behalf of the 2025 ICPC Asia Taichung Regional Contest Judge Team (with Regional Contest Director Ling-Ju Hung, Chief Judge Peter Rossmanith), we hope you enjoy this contest and have fun!

Of course, this contest will be unrated.

For more information about the regional contest, please see the contest website. There will also be live streams!

UPDATE: The contest will be postponed for 15 minutes as the contestants are still entering the contest hall. We are very sorry for the delay.

UPDATE2: The full list of the judge teams, task authors, and the tester teams are up! We will upload solution hints in the next few days, please stay tuned :)

UPDATE3: We have a YouTube playlist covering solutions to most problems. Solution hint documents will be updated soon.

Привет, Codeforces!

Благодаря поддержке Neapolis University Pafos, продолжается серия образовательных раундов.

В 14.11.2025 17:35 (Московское время) состоится Educational Codeforces Round 184 (Rated for Div. 2).

Этот раунд будет рейтинговым для участников с рейтингом менее 2100. Соревнование будет проводиться по немного расширенным правилам ICPC. Штраф за каждую неверную посылку до посылки, являющейся полным решением, равен 10 минутам. После окончания раунда будет период времени длительностью в 12 часов, в течение которого вы можете попробовать взломать абсолютно любое решение (в том числе свое). Причем исходный код будет предоставлен не только для чтения, но и для копирования.

Вам будет предложено 6 или 7 задач на 2 часа. Мы надеемся, что вам они покажутся интересными.

Задачи вместе со мной придумывали и готовили Адилбек adedalic Далабаев, Иван BledDest Андросов, Максим Neon Мещеряков, Роман Roms Глазов и Максим FelixArg Новоточинов. Также большое спасибо Михаилу MikeMirzayanov Мирзаянову за системы Polygon и Codeforces.

Удачи в раунде! Успешных решений!

UPD: Разбор опубликован

ICPC Challenge Championship 2025 hosted and powered by Huawei has just started! It's a 5-hour onsite competition in Shanghai at the new Huawei LianQiu Lake Campus with a monetary prizes for the winners! Who will you be rooting for?

Contestants:

Player-coaches: