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Codeforces Round #690 (Div. 3)

Revision en10, by Stepavly, 2021-01-02 19:09:00

Hello, Codeforces!


Hello! Codeforces Round #690 (Div. 3) will start at Dec/15/2020 17:35 (Moscow time). You will be offered 6 problems (one of them is split into two subtasks) 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 a 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 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 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.

The problems for this round were invented by MikeMirzayanov and prepared by me Supermagzzz and Stepavly

Thanks to MikeMirzayanov for platforms and coordination of our work. Thanks to Sho, kocko, brian, Crazy_hedgehog, manta1130, Rox, Gassa for help in round preparation and testing the round.

Good luck!


UPD: Editorial is published


  Rev. Lang. By When Δ Comment
en10 English Stepavly 2021-01-02 19:09:00 0 (published)
en9 English Stepavly 2021-01-02 19:06:52 15 Reverted to en7
en8 English Stepavly 2021-01-02 19:05:31 15 Tiny change: 'Hello, Codeforc' -> 'Happy New Year, Codeforc' (saved to drafts)
ru6 Russian Supermagzzz 2020-12-15 19:47:26 2 Мелкая правка: '>\n\nUPD: разбор [опу' -> '>\n\nUPD: Разбор [опу'
en7 English Supermagzzz 2020-12-15 19:47:06 2 Tiny change: '>\n\nUPD: editorial i' -> '>\n\nUPD: Editorial i'
en6 English Supermagzzz 2020-12-15 19:46:35 74
ru5 Russian Supermagzzz 2020-12-15 19:46:08 70
en5 English Supermagzzz 2020-12-15 09:02:39 48 Tiny change: '020-12-14] for help' -> '020-12-14], [user:Rox], [user:Gassa] for help'
ru4 Russian Supermagzzz 2020-12-15 09:02:22 48 Мелкая правка: '020-12-14] за помощ' -> '020-12-14], [user:Rox], [user:Gassa] за помощ'
en4 English Supermagzzz 2020-12-14 15:35:08 0 (published)
ru3 Russian Supermagzzz 2020-12-14 15:34:53 0 (опубликовано)
en3 English Supermagzzz 2020-12-14 15:25:48 12 Tiny change: 'ared by me[user:Supe' -> 'ared by me [user:Supe'
en2 English Supermagzzz 2020-12-14 15:25:30 210
en1 English Supermagzzz 2020-12-14 15:25:05 2236 Initial revision for English translation (saved to drafts)
ru2 Russian Supermagzzz 2020-12-14 15:21:06 9 Мелкая правка: 'ривет! Во вторник, [contest_' -> 'ривет! Во [contest_'
ru1 Russian Supermagzzz 2020-12-14 15:20:14 2119 Первая редакция (сохранено в черновиках)