By Zlobober, 31 hour(s) ago, translation, In English,


Midnight tonight (UTC +3) starts the Yandex.Algorithm 2017 Qualification Round. Round lasts for two days in a virtual mode. The contest itself is 100 minutes long. You may start your participation in any moment of time between 21:00 UTC of Friday and 20:59 UTC of Sunday, inclusive.

In order to participate in a competition, you have to complete your registration. It will remain open for everybody until the end of the qualification round.

Those who already successfully submitted at least one problem in a warm-up round are already qualified to the elimination round of the competition. For everybody else in order to be qualified it is necessary to successfully submit at least one problem in a qualification round.

The link to the contest will appear on the site of a competition shortly before the round start time.

Enter the contest!

Let us remind you that discussion of problem statements and solutions is prohibited until 22:40 UTC of Sunday (the latest possible contest end time for a participant). After that you may discuss problems and solutions in comments of this post or the editorial that will appear after the end of competition.

Good luck!

Read more »

  • Vote: I like it  
  • +114
  • Vote: I do not like it  

By RussianCodeCup, history, 38 hours ago, translation, In English,

Hi, everyone!

There are already more than 400 participants who are preparing for the Elimination Round of Russian Code Cup 2017. If you are still among those who has not qualified yet, we invite you to take part in the Third Qualification Round that will take part this Saturday, April 29, at 14-00 Moscow Time. Top 200 participants will also qualify to the Elimination Round and will be able to compete to get to the Final Round of Russian Code Cup 2017.

Good luck and see you at!

Read more »

  • Vote: I like it  
  • +48
  • Vote: I do not like it  

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

Hello Codeforces!

On April 28, 18:05 MSK will be held Educational Codeforces Round 20.

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

Here is the special message from Harbour.Space University for girls from India:

Harbour.Space University offers a unique opportunity to win a FULL SCHOLARSHIP for #womenintechIndia and join our amazing Data Science, Computer Science or Cyber Security Master's Programme in Barcelona, Spain!
Follow this link to complete the application form.

The round will be unrated for all users and it will be held with extented ACM ICPC rules. After that 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 15 minutes to solve them. Though this round may come a bit harder than two previous ones, we still hope that everyone will enjoy problems.

The round was prepared by Ivan BledDest Androsov, Mikhail MikeMirzayanov Mirzayanov and me.

Good luck!

UPD: Editorial is available here

Read more »

  • Vote: I like it  
  • +162
  • Vote: I do not like it  

By MikeMirzayanov, history, 4 days ago, translation, In English,

April 26, 15:35 (UTC) the second Wild Card Round of VK Cup 2017 will take place.

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 2017 - 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!

Read more »

  • Vote: I like it  
  • +96
  • Vote: I do not like it  

By gainullin.ildar, history, 7 days ago, translation, In English,


On April 23, 19:35 MSK will be held rated Tinkoff Challenge – Elimination Round.

Problems were prepared by me — Ildar Gainullin, Alexander alkurmtl Kurilkin and Nikolay KAN Kalinin.

Big thanks to Vladislav winger Isenbaev and Alexander AlexFetisov Fetisov for testing round, and also to Mike MikeMirzayanov Mirzayanov for systems Codeforces and Polygon.

Participants will be offered seven problems and two hours to solve them. Scoring will be announced a bit later.

This round is eliminational for Tinkoff Challenge.

Best 30 participants will be awarded with warm vests and other pleasant souvenirs like stickers and notepads. Best 100 participants will be invited to Moscow to visit Tinkoff's office with panoramic view on the city.

Best 20 participant who will be able to arrive will advance to Tinkoff Challange – Final Round.

We hope everyone will find interesting problem for themselves. We wish everyone a successful round and high ratings!

UPD. Scoring: 500 1000 1500 2000 2500 3000 3500

UPD. Editorial

Read more »

  • Vote: I like it  
  • +424
  • Vote: I do not like it  

By reality, history, 9 days ago, In English,

Hi everyone!

I'm pleased to announce Codeforces Round #410 (Div. 2) that will take place on Friday, 17:35 MSK. I'm the writer of the round.

I'd like to say thanks to Alex netman Vistyazh and Marcel yosei-san Bezdrighin for feedback and help in preparing the round and to MikeMirzayanov for awesome platforms : Codeforces and Polygon.

I hope you will like the problems.

Good luck and have fun!

UPD: Scoring distribution: 500 — 1000 — 1500 — 2000 — 2500

UPD 2. The round is finished. Congratulations to winners:

Div 2:

  1. Gonens

  2. Blue_Sky.

  3. kimnoia

  4. RAG3

  5. jtnydv25

Div 1:

  1. OnionPringles

  2. unused

  3. uwi

  4. Reyna

  5. alexrcoleman

Editorial: Link

Read more »

  • Vote: I like it  
  • +237
  • Vote: I do not like it  

By lewin, 2 weeks ago, In English,


The round 2 of VK Cup 2017 will take place on April 16 at 18:35 MSK (check your timezone here), along with separate div1 and div2 Codeforces Round #409. The contest "VK Cup 2017 — Round 2" is for teams qualified from round 1. The top 100 teams will advance to the Round 3, while other ones will have one more chance in the Wild Card Round 2 later this month. Those who don't participate in the VK Cup can take part in the Codeforces Round #409 individually (problems will be available in English too). All three rounds last 2 hours, and all are rated.

The round would not be possible without the following people (in no particular order): KAN, Errichto, winger, AlexFetisov, LiChenKoh, xiaowuc1, MikeMirzayanov. Additionally, I thank VK company for sponsoring this contest.

As usual, the scoring distribution will be announced later.

UPD 1: The scoring distribution is as follows:

div2: 500 — 1000 — 1500 — 2000 — 2750

div1 and official round: 500 — 1000 — 175022502250

UPD 2: The tutorial is available here:

Congratulations for the winners

Official round:

  1. LHiC, V--o_o--V
  2. I_love_Tanya_Romanova, enot110
  3. netman, andrew.volchek
  4. aid, ershov.stanislav
  5. MrDindows, Rubanenko

div 1:

  1. SirShokoladina
  2. moejy0viiiiiv
  3. jcccccccccccccccccccccsb
  4. TakanashiRikka
  5. Um_nik

div 2:

  1. ngkan146
  2. AlwaysWrong
  3. fgvfgfg1
  4. DryukAlex
  5. DorMOUSENone

Read more »

Announcement of VK Cup 2017 - Round 2
  • Vote: I like it  
  • +217
  • Vote: I do not like it  

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

Hello everyone!

Top 200 from the First Qualification Round have already advanced to the Elimination Round, but the other paricipants still strive to get there. If you haven't qualified yet, we invite you to take part in the Second Qualification Round that will take place this Sunday, April 16, at 12-00 Moscow Time. Best 200 participants will advance to the Elimination Round, other participants can try again in the Third Qualification Round.

Good luck to everyone, see you at!

Read more »

  • Vote: I like it  
  • +41
  • Vote: I do not like it