By niyaznigmatul, 19 hours ago, translation, In English,


The second qualifier to Innopolis Open 2020 rescheduled to December 14th 1:00 PM UTC.

Qualifier duration is 5 hours, there are five problems in the contest. Those, who scored high enough, will be invited to the final contest that takes place on February 22-23, 2020. Those, who already qualified, can compete in second qualifier as well, but they won't influence qualification.

Innopolis Open is only for middle and high school students. All others will be able to solve the problems in Codeforces::Gym.

There is a trial round taking place, it ends in the evening of December 13. If you are new to Innopolis Open it's good to take part in trial round to get to know the testing system and format of problems. Be careful, the trial round and qualifier don't take place on Codeforces website. To take part in the trial round or the qualifier you are required to sign up on Innopolis Open website. Don't forget to read the rules and the testing system guide on the website.

First qualifier took place several weeks ago, you can try to solve the problems in Codeforces gym: Innopolis Open 2019-2020, qualification, contest 1.

Previous year contests. Be careful, some of them may be in ICPC format:

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By Vovuh, history, 2 days ago, translation, In English,

UPD: Editorial is published!


Hello! Codeforces Round #605 (Div. 3) will start at Dec/12/2019 16:35 (Moscow time). You will be offered 6 or 7 problems (or 8) with expected difficulties to compose an interesting competition for participants with ratings up to 1600. However, all of you who wish to take part and have rating 1600 or higher, can register for the round unofficially.

The round will be hosted by rules of educational rounds (extended ACM-ICPC). Thus, during the round, solutions will be judged on preliminary tests, and after the round it will be a 12-hour phase of open hacks. I tried to make strong tests — just like you will be upset if many solutions fail after the contest is over.

You will be given 6 or 7 (or 8) problems and 2 hours to solve them.

Note that the penalty for the wrong submission in this round (and the following Div. 3 rounds) is 10 minutes.

Remember that only the trusted participants of the third division will be included in the official standings table. As it is written by link, this is a compulsory measure for combating unsporting behavior. To qualify as a trusted participants of the third division, you must:

  • take part in at least two rated rounds (and solve at least one problem in each of them),
  • do not have a point of 1900 or higher in the rating.

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.

Thanks to MikeMirzayanov for the platform, help with ideas for problems and for coordination of my work. Thanks to my good friends Daria ZeroAmbition Stepanova, Mikhail PikMike Piklyaev, Maksim Ne0n25 Mescheryakov and Ivan BledDest Androsov for help in round preparation and testing the round.

Good luck!

I also would like to say that participants who will submit wrong solutions on purpose and hack them afterwards (example) will not be shown in the hacking leaders table.


UPD: Great thanks to Artem rox Plotkin and Dmitrii opukittpceno_hhr Umnov for testing the round and help with bugs fixing! Artem is also proposed one of the problems for today's round!

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By chemthan, 9 days ago, In English,

Hello everyone!

I am glad to invite you to Codeforces Round #604, which will take place on Dec/05/2019 17:35 (Moscow time). The round will be rated for both divisions.

Exactly 300 Codeforces rounds passed since my first one (Round 304). I have learned a lot of things here and have much fun in participating in the competitions. Now, I want to contribute to this community by proposing some problems. I hope that you will find something interesting in solving them.

The contest is prepared by me, laoriu, I_love_Hoang_Yen, coordinator isaf27 and CF admin MikeMirzayanov. As usually, we must specially thank to below people who make contest possible:

There will be roughly 6 problems in each division. Scoring will be announced later.

GL & HF! See you on the scoreboard.

UPD 1: Scoring

  • D1: 500 1000 1500 (1000+1000) 2250 3000.
  • D2: 500 1000 1500 2000 2000 2500.

UPD 2: Thanks for participating! Congratulations to the winners!

Top 5 Div1:

Top 5 Div2:

UPD 3: Sorry for delay, this is editorial.

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By kuviman, 10 days ago, translation, In English,

Hello everyone!

Mail.Ru Group announces start of the annual artificial intelligence programming championship — AI Cup 2019.

AI Cup — open artificial intelligence programming contest. Test yourself writing a game strategy! It’s simple, clear and fun!

This year's theme is — platformer. We are waiting for you on our site! The site is already open, you can start implementing your strategies.

Eighth AI Cup championship is named CodeSide. You are to program an artificial intelligence to control a team of units. Your strategies will compete with each other in the Sandbox and the championship. Currently availiable programming languages: C++, C#, F#, D, Go, Java, Kotlin, Scala, Python, Ruby, Rust. The Sandbox is already open. Good luck!

Currently the championship is in beta-test mode, and on December 7th Sandbox will start working officially!


  • Sandbox: open for everyone from November 27; until December 7 will be beta-testing, system instability and significant changes in the rules are possible during this period.
  • Round 1: December 14-15.
  • Round 2: December 21-22.
  • Finals: December 28-30.


  • 1-st place — MacBook Pro 15
  • 2-nd place — MacBook Pro 13
  • 3-rd place — Apple iPad
  • 4-th place — Samsung Gear S3 or Apple Watch S4
  • 5-th place — WD My Cloud 6 TB
  • 6-th place — WD My Passport Ultra 4TB

Moreover, the top-6 sandbox winners will get WD My Passport Ultra 2TB. All participants in the Round 2 will get T-shirts, and the participants of the Finals will get hoodies.

Begin from the Quick start guide. Writing a simple strategy is not hard at all!

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By NeercNews, 2 weeks ago, translation, In English,

Hello friends!


ICPCLive broadcast



This weekend we'll hold two large-scale final stages of important Championships in the region: ICPC Northern Eurasia Finals 2019 and Russia Open High School Team Programming Contest.

Competitions are traditionally held at several places: in St. Petersburg, Barnaul, Almaty, Tbilisi and Kremenchuk. School teams will fight for the "Champions of Russia" Cup. Student teams will meet in a serious intellectual fight for places to the ICPC 2020 World Finals, which will be held on June 25 in Moscow. This is going to be the third final organized in our region.

Of course, join ICPCLive broadcasts for live-streaming from both events. Live streams are expected from the opening of the championship, both contests, and closing ceremonies.

UPD: Congratulations to teams of ICPC 2020 finalists!

  • SPb SU: 25 (Belichenko, Bykov, Petrov)
  • Nizhny Novgorod SU: Almost Retired (Daniliuk, Kalinin, Ryabchikova)
  • MIPT: Godnotent (Belykh, Golovanov, Sergunin)
  • SPb ITMO: 1 Standard deviation (Budin, Kirillov, Sayutin)
  • Innopolis: 1 (Gaivoronskiy, Khakimiyon, Yalalov)
  • HSE: Logarifmya4ka (Anoprenko, Romanov, Safonov)
  • Belarusian SU: #1 (Dubovik, Karabeinikau, Kernazhytski)
  • Latvia: 2 (Civkulis, Zajakins, Zajakins)
  • Moscow SU: NoNames (Chunaev, Kalendarov, Koshelev)
  • SPb HSE: Last Hope (Bogomolov, Labutin, Podguzov)
  • Saratov SU: 1 (Meshcheryakov, Petrov, Piklyaev)
  • Belarusian NTU: #1: Great team (Sheftelevich, Vasileuski, Zdanovich)
  • Kazan FU: 2 (Ilikayev, Kapralov, Yagafarov)
  • Yerevan SU: One Last Dance (Galstyan, Muradyan, Mikaelyan)
  • International IT University: 2 (Kuanyshbay, Niyazbekov, Khlinovskiy)
  • Belarusian SUIR: #2 (Shavel, Udovin, Vishneuski)


269 teams were invited to participate in the final stage of the competition. 128 of them will meet in Saint Petersburg in the historical park "Russia — is my history". 49 teams will compete in Barnaul, 56 teams — in Almaty and 18 teams will take part in the competition in Tbilisi and Kremenchuk.

The main round of the championship will begin this Saturday (30 November) at 10:00. As the tour starts, we'll add links for you to monitor results.

Some teams that have high chances of becoming Cup winners are listed in the table below:

Team City Participant 1 Participant 2 Participant 3 Rating
Power of Three St.Petersburg Ефремов Андрей
Гайнуллин Ильдар
Одинцов Андрей
Mex Foundation Moscow Лифарь Егор
Савкин Семён
Шеховцов Александр
Graneli Tbilisi Birkadze Nika
Toloraia Teimuraz
Basadzishvili Archil
а) Moscow Ушаков Фёдор
Федосеев Тимофей
Пискалов Дмитрий
Ого! Кажетсья это $#@! Moscow Логинов Игорь
Шуклин Максим
Садовничий Антон
Преимущественно овощи Kazan Миннахметов Булат
Харисов Булат
Исмагилов Азат

More teams with their total ratings you can see in the post. Thank you very much, ismagilov.code!

Northern Eurasia Finals

Student competitions will start this Sunday, December 1 at 9:30(Moscow time) at four sites: the historical Park in St. Petersburg, the Altai state technical University in Barnaul, the Georgian University of Business and Technology in Tbilisi and the Kazakh-British Technical University in Almaty.

Links to the results table, as well as the tasks of the contest will be provided soon after the start of the main round of the competition.

If you don't plan to participate in the semifinals, you can try your hand at the challenges of the Northern Eurasia finals in the mirror.

We're going to follow the teams and tell you about the news! Note that the results of this contest dictates which teams will be selected to represent the North Eurasia Region on World Finals ICPC 2020.

Some teams with their total ratings, which we're going to follow especially closely listed in a table below:

Team Participant 1 Participant 2 Participant 3 Rating
SPb ITMO: 1 Standard deviation Николай Будин
Дмитрий Саютин
Арсений Кириллов
MIPT: Godnotent Александр Голованов
Евгений Белых
Андрей Сергунин
Moscow IPT: Fennecs Дмитрий Григорьев
Николай Третьяков
Денис Шпаковский
NN SU: Almost Retired Алексей Данилюк
Николай Калинин
Валерия Рябчикова
"Belarusian SU: Belarusian SU #1" Егор Дубовик
Александр Керножицкий
Федор Коробейников
HSE: Logarifmya4ka Владимир Романов
Михаил Анопренко
Иван Сафонов
SPb SU: Havka — ne papstvo Егор Горбачев
Михаил Иванов
Савелий Григорьев
SPb SU 25 Дмитрий Беличенко
Никита Быков
Семен Петров
SPb SU: LOUD Enough Никита Гаевой
Иван Бочков
Владислав Макаров

Share with us your news, impressions, and photos with hashtags #NEF and #ВКОШП.

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By Supermagzzz, history, 2 weeks ago, In English,

Hello Codeforces!

We, Supermagzzz, Stepavly, AdvancerMan, unreal.eugene, are ITMO students, who want to contribute to Codeforces community, went to MikeMirzayanov and offered him to help with rounds testing. But MikeMirzayanov invited us to create our own round with his help. And now...

We're glad to invite you to Codeforces Round #603 (Div. 2), which will be held on Nov/29/2019 17:35 (Moscow time). It will be rated for all participants with a rating below 2100. You will be given six problems and two hours to solve them.

The problems were invented and prepared by Supermagzzz, Stepavly, AdvancerMan, unreal.eugene, MikeMirzayanov.

Special thanks to:

  • MikeMirzayanov for great systems Codeforces and Polygon and coordinating round preparation.

UPD: Scoring: 500 — 1250 — 1250 — 1750 — 2500 — 3000

We hope you will enjoy the problems. Good luck, wish you a high rating!

UPD1.5: Thanks for participating! Congratulations to the winners!

Top 5 Div. 2:

  1. Lazyeval
  2. twitch.tv_wookje
  3. Byzantium
  4. rainboy
  5. fuyuki

Top 5 Div. 2 + unoffical:

  1. Lazyeval
  2. twitch.tv_wookje
  3. socketnaut
  4. KrK
  5. Byzantium

UPD2: Editorial is out!

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By PikMike, history, 2 weeks ago, translation, In English,

Hello Codeforces!

On Nov/27/2019 16:50 (Moscow time) Educational Codeforces Round 77 (Rated for Div. 2) will start.

Series of Educational Rounds continue being held as Harbour.Space University initiative! You can read the details about the cooperation between Harbour.Space University and Codeforces in the blog post.

This round will be rated for the participants with rating lower than 2100. It will be held on extended ICPC rules. The penalty for each incorrect submission until the submission with a full solution is 10 minutes. After the end of the contest you will have 12 hours to hack any solution you want. You will have access to copy any solution and test it locally.

You will be given 6 problems and 2 hours to solve them.

The problems were invented and prepared by ZiXuan Yan RDDCCD, Roman Roms Glazov, Adilbek adedalic Dalabaev, Vladimir Vovuh Petrov, Ivan BledDest Androsov, Maksim Ne0n25 Mescheryakov and me. Also huge thanks to Mike MikeMirzayanov Mirzayanov for great systems Polygon and Codeforces.

Good luck to all the participants!

Our friends at Harbour.Space also have a message for you:

Hello Codeforces!

This week we have two new blog posts and a reminder of our Data Science Scholarship!



We are offering fully-funded international scholarships for exceptional tech specialists from around the world. Accelerate your career by becoming an industry expert capable of making key data-driven decisions that add value and drive innovation within tech industries.

Harbour.Space University has partnered with SCG, a leading business conglomerate in the ASEAN region, to offer exceptional tech specialists the opportunity to work and study in two of the most dynamic and vibrant cities in the world. Join our progressive two-year program based in Bangkok, with 6 of the 24 months in Barcelona, to develop the international mindset needed to accelerate your career and redefine how data drives the businesses of the future.

Codeforces and Harbour.Space

Tuition fee:

2 years | €45,800


3 hours of study per day | 15h per week

Work Experience:

4 hours of internship per day at SCG | 20h per week

Living Allowance:

€16,800 euros | €700 per month living allowance


Congratulations to the winners:

Rank Competitor Problems Solved Penalty
1 twitch.tv_wookje 6 209
2 Tweetuzkokodayo 6 219
3 socketnaut 6 220
4 mango_lassi 6 280
5 LJFOO7 6 288

Congratulations to the best hackers:

Rank Competitor Hack Count
1 Rian_5900 60:-3
2 blaction 13
3 Fyodor 14:-5
4 Wolfy626 11
5 bmm 11:-2
216 successful hacks and 246 unsuccessful hacks were made in total!

And finally people who were the first to solve each problem:

Problem Competitor Penalty
A dorijanlendvaj 0:01
B dorijanlendvaj 0:02
C dorijanlendvaj 0:07
D 0:19
E PinkRabbit 0:16
F _Kuroni_ 1:19

UPD: Editorial is out

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