Codeforces Round #857 (Div.1, Div.2, based on Moscow Open Olympiad in Informatics, rated)

Revision en4, by vaaven, 2023-03-13 19:37:45


Right now happens the first tour of the Open Olympiad in Informatics, and tomorrow will be the second one. This contest is prepared by Moscow Olympiad Scientific Committee that you may know by Moscow Team Olympiad, Moscow Olympiad for Young Students and Metropolises Olympiad (rounds 327, 342, 345, 376, 401, 433, 441, 466, 469, 507, 516, 541, 545, 567, 583, 594, 622, 626, 657, 680, 704, 707, 727, 751, 775, 802, 829, 852).

Open Olympiad consists of the most interesting and hard problems that are proposed by a wide community of authors, so we decided to conduct a Codeforces regular round based on it, which will happen on Mar/09/2023 12:35 (Moscow time) and will be based on both days of the Olympiad. Note the unusual time of the round. Each division will have 7 problems and 3 hours to solve them.

We kindly ask all the community members that are going to participate in the competition to show sportsmanship by not trying to cheat in any manner, in particular, by trying to figure out problem statements from the onsite participants. If you end up knowing some of the problems of Moscow Open Olympiad (by participating in it, from some of the onsite contestants or in any other way), please do not participate in the round. We also ask onsite contestants to not discuss problems in public. Failure to comply with any of the rules above may result in a disqualification.

Problems of this competition were prepared by Mangooste, Artyom123, teraqqq, Ziware, vaaven, Tikhon228, Ormlis, Kirill22, ViktorSM, isaf27, DebNatkh and DishonoredRighteous guided by grphil and Helen Andreeva.

Thanks to Aleks5d for the round coordination, statement translation and preparation of problems for the second division, and also thanks for MikeMirzayanov for systems Codeforces and Polygon, which was used to prepare problems of this olympiad.

Good luck everybody!

Due to the official competition source codes of other participants will not be available for an hour after the end of the round.

UPD1: Please note the number of problems and the duration of the round have been increased for each of the divisions.

UPD2: Great thanks to the testers of the round: BucketPotato, valeriu, 4qqqq, Aaeria, FedeNQ, olya.masaeva! As well as the testers of the main Olympiad: Siberian, Maksim1744, antony191, Kapt, Pechalka, alexxela12345, Be_dos, princebelkovetz, Jatana, KiruxaLight, cute_hater!

UPD3: Scoring distribution:

Div.2: 500 — 750 — 1250 — 1750 — 2000 — 2500 — 3500

Div.1: 500 — 1000 — 1250 — 1750 — 2500 — 3500 — 3500

UPD4: Editorial, we apologize for the delay:(


  Rev. Lang. By When Δ Comment
en4 English vaaven 2023-03-13 19:37:45 97 Tiny change: 'ry/113857)' -> 'ry/113857), we apologize for the delay:('
ru6 Russian Ormlis 2023-03-13 18:45:28 18 Мелкая правка: 'ry/113857), простите за задерж' -> 'ry/113857). Приносим извинения за задерж'
ru5 Russian vaaven 2023-03-13 18:44:00 1 Мелкая правка: 'ry/113857) простите ' -> 'ry/113857), простите '
ru4 Russian vaaven 2023-03-13 18:43:40 88 Мелкая правка: 'dash; 3500' -> 'dash; 3500\n\n**UPD4:** Разбор: ( извините, что так долго:( )'
en3 English Ormlis 2023-03-09 02:15:52 947
ru3 Russian Ormlis 2023-03-09 02:12:00 906 Мелкая правка: 'ивизионов. **' -> 'ивизионов.**'
ru2 Russian Ormlis 2023-03-08 15:57:29 0 (опубликовано)
en2 English Ormlis 2023-03-08 15:57:13 0 (published)
en1 English Ormlis 2023-03-08 15:51:42 3886 Initial revision for English translation (saved to drafts)
ru1 Russian Ormlis 2023-03-08 15:43:58 3927 Первая редакция (сохранено в черновиках)