By KAN, 2 days ago, translation, In English,

Hi everyone!

digital resistance

Tomorrow, on the April 25-th, 2018 at 17:35 UTC we are holding Codeforces Round #476 (Div. 2) [Thanks, Telegram!]! The round will be rated for the second division participants, members with higher rating can take part out of competition.

I give the floor to MikeMirzayanov to announce the round:

This round opens a series of thanks-rounds to those who significantly supported Codeforces in the crowdfunding campaign for the 8th anniversary. Although Telegram is not explicitly present on the list of donators, for us this is the first and most important friend. We express our gratitude to Telegram and personally to Pavel Durov for the constant support and send regards from programming contest community. Now that the medieval inquisition against Telegram and all the free Internet has been declared in our country, I admire and express support for Pavel's principled position on protecting our rights and freedoms. Thank you, Telegram!

I join the thanks to Telegram, and also want to thank neckbosov and Livace who helped me with the problems for the round. Also many thanks to gritukan, GreenGrape and 300iq for their help in round preparation, and arsor for translation.

Good luck!

Congratulations to winners!

Div. 2:

  1. Akylbeek — solved all problems!
  2. aho_kolyasik
  3. reeWorld
  4. 16bit075
  5. teamskiy

Div. 1:

  1. uwi
  2. quailty
  3. retrograd
  4. I_love_Maria_Ivanova
  5. Adalbert

The analysis is here.

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By kuviman, 4 days ago, translation, In English,


Hello everyone! was created ~16 years ago by programming contests participants from Saratov university: MikeMirzayanov and andrewlazarev. Today its codebase and infrastructure are completely outdated, and supporting it is unreasonably hard. Nonetheless, Codeforces team is regularly asked to revive acmsguru, since there is still a lot of interest in the problemset.

Here is the new functionality in Codeforces — additional section "acmsguru" in Problemset. All the problems from the old system are moved there. There are still a few things to do here: correctly port interactive problems, improve looks of statements, support the new section in Codeforces API, support adding these problems to mashups.

Anyway, you can solve the problems already, and view progress on separate standings page for acmsguru.

To save the spirit of acmsguru, viewing sources of other participants is disabled.

UPD: In some old problems checkers are compiled into 16-bit executables, so testing of these problems is temporarily not working.

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By MikeMirzayanov, 9 days ago, translation, In English,

April 19, 15:35 (UTC) the VK Cup 2018 - Wild-card Round 2 will start.

Participants are invited to achieve progress in solving an unusual problem. VK Cup teams which were advanced to the Round 2 (and didn't advance to the Round 3) will take part in VK Cup 2018 - Wild-card Round 2 officially. In addition, this round will be open to the public for unofficial participation for everybody. Registration will be open for the whole round duration.

The round will be one week long. After the end latest submission (with positive score) of each participant will be judged on system tests.

Good luck!

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By gKseni, 9 days ago, translation, In English,

ACM-ICPC World Finals 2018 will begin on April 19, 2018 at 2:00 (UTC). This event is the main event of the year in the world of sports programming!

In the past 20 years alone, ICPC participation has increased by more than 2000%. Last year, ICPC Regional participation included 49,935 of the finest students and faculty in computing disciplines from 3,098 universities in 111 countries on six continents. A record 53,446 students and 5,411 coaches competed in ICPC and ICPC-assisted competitions last year, setting new records in participation.

Codeforces wishes the teams to show a vivid and interesting contest. We wish to find beautiful solutions, write without bugs and enjoy many accepted problems!


ACM ICPC World Finals 2018 English Broadcast:
ACM ICPC World Finals 2018 Chinese Broadcast:
ACM ICPC World Finals 2018 Arabic Broadcast:
ACM ICPC World Finals 2018, Split screen:
Broadcast from legends: Petr, tourist, Endagorion:
Watch the live translation on
Broadcast from legends: OO0OOO00O0OOO0O00OOO0OO, rng_58, FizzyDavid:
Watch the live translation on
2018 ICPC World Finals, Closing ceremony:

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By ICPCNews1, history, 8 days ago, In English,

More than 300,000 students competed worldwide in local and regional events with one aim — to participate in World Finals, this year hosted by Peking University in China. And today we will see who will become the world champion!

A total of 140 teams of three students will face about 12 difficult problems (we don't know the number until the problem set is released!). They will have 5 hours to solve the problems.

Although the contest itself takes 5 hours only, the whole event takes 5 days. So, what is going on during these days?

Through the registration evening, each team was given different color shirt and their badges, as well as other goodies like a backpack and a cute stuffed panda bear. We took photos and videos of each team so we can share about them on various social media.

Monday began with JetBrains TechTrek Presentation and a really fun sponsor showcase with games and activities. Contestants could participate in many things — they could try writing Chinese characters, playing traditional Chinese games or instruments, try sports in VR and more... The day was ended with a stunning concert of both traditional and contemporary Chinese music from Peking University, including some original compositions.

On Tuesday we were amazed by The Giant Wall of China. That day we become true men because the Chinese saying is that one is not fully human until he climbs the Great Wall. It was surprisingly steep. Hundreds of people from 6 continents climbed it and had amazing views of the mountains.

The afternoon was all about the opening ceremony, which had speeches, awards for many wonderful people and a presentation of all the teams, interlaced with cultural performances.

Wednesday was an important dress rehearsal. The program is similar to the competition day. It lets everyone find issues so the finals on Thursday can run as smoothly as possible. There are always some technical issues, problems with logging in, printers, etc., but they all got worked out. In the afternoon, contestants had a rest, enjoy a sponsors' ChillZone with games and do the last preparations for the tomorrow's contest.

140 teams participate in world finals. But there are many other people standing behind scenes — coaches, organizers, judges, ICPC teams (News, Services,...) and many other volunteers, totalling in about 1000 people!

The ACM ICPC world finals aren't only about competing. It is also about meeting with great programmers from all around the world, encountering other cultures and sharing the joy of programming. For me, this event is truly awesome and fun to be part of!

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By voidmax, 11 days ago, translation, In English,

Tinkoff Internship Warmup Round 2018 and Codeforces Round #475 will start at 17 April 2018 17:05,

Thanks to Vladislav winger Isenbaev, Alex AlexFetisov Fetisov, Ildar 300iq Gainullin, Egor egor.lifar Lifar, Philip grphil Gribov and Gleb glebodin Lobanov for testing my problems.

Special thanks to Grigory gritukan Reznikov and Nikolay KAN Kalinin for coordinating throughout the round and Mike MikeMirzayanov Mirzayanov for remarkable systems Codeforces and polygon.

Round is rated for both divisions. There are 5 problems, and 2 hours to solve them. The points distribution will be updated later.

Good luck and Have fun!

UPD The points distribution for both divisions: 500 — 1000 — 1500 — 2000 — 2500

UPD Congratulations to the winners!

Div 1:

Div 2:

UPD >>> Editorial <<<

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By scott_wu, history, 12 days ago, In English,

Hey all!

For the past few months, vnovakov and I have been working on a product called Lunch Club that connects people algorithmically in cities and events around the world. We'll be running Lunch Club at ICPC WF this week as a way for contestants and alums to get to meet one another. Lunch Club will be making matches for 1:1 lunches Monday and Tuesday at the hotel. If you're at ICPC and are interested in meeting cool people, sign up here!

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By dj3500, 2 weeks ago, In English,

UPDATE: the editorial is here

Hello CodeForces! This year again, I'd like to invite you to the online mirror of an open championship of Switzerland called HC2 (the Helvetic Coding Contest). A mirror was also held last year and two years ago.

The Helvetic Coding Contest is a yearly contest held at the EPFL in Lausanne by the PolyProg association. The contest itself took place on March the 17th, but the online mirror is scheduled on Saturday, 14th of April, 10:05 Moscow time. The duration is 4:30.


  • you can participate in teams or individually (1-3 people),

  • standard ACM-ICPC rules (no hacking),

  • the contest is not rated,

  • if you have participated in the onsite contest, please do not participate in the mirror.

The contest this year is Star Wars-themed. It features 6 series of 2-3 related tasks with increasing difficulty (easy/medium/hard). Sometimes it may be the case that a solution for the hard version solves all of them, but usually not. We think that the problemset is diverse and interesting, and while the contest is ACM-style, you will find that some problems are not so standard. Most easy&medium problems are even solvable in Python, so you can also recommend this contest to your newbie friends :) We promise to post a nice editorial as soon as the contest ends.

Acknowledgments: the problems were set by maksay, boba5551, mukel, DamianS, esrever, and myself. Thanks also go out to people who helped with the statements and testing: bgamlath, Michalina Pacholska (who also draws the cows), and KAN for CodeForces coordination, as well as everyone involved in the actual onsite contest, who are too many to name here. We also thank the sponsors Open Systems and AdNovum. Lastly, thanks to MikeMirzayanov for CodeForces and Polygon (which was used to prepare the problems).

Finally, in a bit of autopromotion, note that you can use Hightail to automatically test your solutions :) Good luck!

After-contest UPDATE:

>>> Editorial <<<

Feel free to ask questions in this topic.

Thanks to everyone who participated! We hope you have enjoyed the problems despite the interruption in judging. The top 4 teams, who have solved all problems, are:

  1. SpicyFriedTomatoes: mjy0724, OO0OOO00O0OOO0O00OOO0OO

  2. (`・ω・´): King_George, OhWeOnFire, FizzyDavid

  3. ymd队长ioi捧杯超稳: yjq_naiive, fjzzq2002, yanQval

  4. ★SweeT DiscoverY★: dotorya, cki86201, zigui

See you again next year!

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Tags hc2
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By MikeMirzayanov, 2 weeks ago, translation, In English,

Hello Codeforces!

On April 10, 14:35 UTC Educational Codeforces Round 42 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 Div. 2. It will be held on extented ACM ICPC rules. After the end of the contest you will have one day to hack any solution you want. You will have access to copy any solution and test it locally.

You will be given 7 problems and 2 hours to solve them.

The problems were prepared by me and Alex fcspartakm Frolov.

We'd like to thank Nikolay KAN Kalinin, Grigory gritukan Reznikov, Vladimir Vovuh Petrov for the testing and help in preparing the round.

Good luck to all participants!

UPD: Some information from Harbour.Space U

The third Hello Programming Bootcamp finished as teams from around the world learned, competed, and got to know each other in the cities of Kollam and Moscow.

“I'm positively surprised with the level and number of Indian teams. I believe when following a systematic and regular training schedule — they will certainly attend top world records in programming” says Mike MikeMirzayanov Mirzayanov.

The results of the India boot camp are as follows:

We would like to congratulate the top teams from the India side in both divisions A and B — and especially recognise division A’s winner: Team SDV — Vasily platypus179 Alferov, Vaibhav gvaibhav21 Gosain, Motasem Motarack AL-Kayed sponsored by Social Discovery Ventures, and winners of the Educational Codeforces Round 39.

The division A winners are: Team SDV (platypus179, gvaibhav21, Motarack), TheVindicators (IIIT Kharagpur) (evil666man, Chenghiz), DomiNUS (NU of Singapore) (vodanhna, darknsux, minh141198).

The division B winners are: BEU Programmers (Baku Engineering University) (mahmud2690, Mamedov, fuck_coderinuse), Penza State University (Fortin, WooDeND, Key_J) and Sab_lite_hai (IIT(BHU),Varanasi) (Enigma27, Dsingh_24, nitishk24).

All results from India side
All results from Russia side

From the ever present in ACM World Finals city of Moscow, to the new-comer on the world stage city of Kollam — Hello India x Russia Programming Bootcamp showcased heart, passion, and a universal drive towards a better competition.

“It's the first time I participate at Hello ACM-ICPC Bootcamp in Asia and I admire local hospitality and students motivation. Everyone seems to be eager to learn, participants stay very late upsolving the contest problems and revising the topics they were thought during the day” states Gleb GlebsHP Evstropov, The Coordinator of the Programming Committee.

The latest in world finals simulation training would not be possible without the bronze sponsorship of VTB, the institute with the most extensive international network of any Russian bank, boasting more than 30 banks and financial companies in more than 20 countries.

Fill out this form and we will keep you up to date on our next boot camp!

UPD: Tutorial

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By Zlobober, 3 weeks ago, translation, In English,

Hi everybody! Tomorrow at 12:00 UTC there will be the third round of Yandex.Algorithm 2018. You can enter contest from the Algorithm main page.

This round is written by me with a great help of GlebsHP and everybody who was testing the round. While solving the problems, you will be helping some of my colleagues here at Yandex to deal with some practical (or not) situations. Good luck to everybody!

Enter the contest

UPD: Round is over! Congratulations to Merkurev, j_______________________ and Um_nik who got first three places in the standings.

The elimination stage is over and we can now find out who are the contestants that are going to compete in the Algorithm Finals in Saint Petersburg: elimination scoreboard.

There is also a round editorial (ENG only) available.

Good luck and see you later!

Important information for Opencup participants

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