Codeforces Round #879 (Div. 2, based on All-Russian olympiad in the name of Keldysh) [Rated]

Revision en15, by Ormlis, 2023-06-18 15:27:58

Hi!

This Sunday will take place All-Russian olympiad for students of 5-8 grades, in the name of Keldysh. Good luck to all the participants! This contest is prepared by Moscow Olympiad Scientific Committee that you may know by Moscow Team Olympiad, Moscow Olympiad for Young Students, Moscow Open Olympiad in Informatics (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, 857).

We are happy to announce Codeforces Round 879 (Div. 2) based on the problems of this olympiad! It will be a Div. 2 round, which will take place at Jun/18/2023 11:05 (Moscow time). Please notice the unusual time. You will have 6 problems and 2 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 All-Russian olympiad in the name of Keldysh (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 grphil, Mangooste, sevlll777, Siberian, TeaTime, teraqqq, Ziware, TheEvilBird, Ormlis, Alexdat2000, vaaven, Mikhango, Artyom123 guided by Ormlis, grphil and Helen Andreeva.

Thanks to Artyom123 for the round coordination, and also thanks to MikeMirzayanov for systems Codeforces and Polygon, which was used to prepare problems of this olympiad.

Great thanks to the testers of the round: PurpleCrayon, He_Ren, feecIe6418, penguinhacker, ix35, Dominater069, MagicalFlower, tzc_wk, gyh20, ezraft, Kieray, AquaMoon, satori_____, njupt_lyy, Mike4235, ak2006, Lavine, Ritwin, xiaossr, turmax, fastmath, Kapt, Kirill22, Be_dos, Olerinskiy, gmusya, blyat, vsinitsynav, orz, TheGoodest, playerr17, lesssia.

UPD1: Scoring distribution:

500 – 1000 – 1250 – 1750 — 2500 – 3000

Good luck everybody!

UPD2: Editorial

UPD3: Winners!

Official:

  1. Final_Brave_Niuniu
  2. tzc___________________wk
  3. MoFalkmusic
  4. do_while_not_not_true
  5. Cherrt

Unofficial:

  1. hank55663
  2. stkwill
  3. jiangly
  4. Sugar_fan
  5. Brovko

History

 
 
 
 
Revisions
 
 
  Rev. Lang. By When Δ Comment
ru13 Russian Ormlis 2023-06-18 15:28:48 396
en15 English Ormlis 2023-06-18 15:27:58 389
ru12 Russian Ormlis 2023-06-18 14:26:28 68
en14 English Ormlis 2023-06-18 14:25:57 70
ru11 Russian Artyom123 2023-06-18 13:16:30 27 Мелкая правка: 'едставить Codeforces Round #879 на основе' -> 'едставить [contest:1834] на основе'
en13 English Artyom123 2023-06-18 13:15:57 31
ru10 Russian Artyom123 2023-06-17 22:25:09 97
en12 English Artyom123 2023-06-17 22:23:46 82
ru9 Russian Artyom123 2023-06-17 19:25:26 12 Мелкая правка: ':TheGoodes], [user:p' -> ':TheGoodest], [user:p'
en11 English Artyom123 2023-06-17 19:25:15 12 Tiny change: ':TheGoodes], [user:p' -> ':TheGoodest], [user:p'
en10 English Artyom123 2023-06-17 19:24:40 339
ru8 Russian Artyom123 2023-06-17 19:24:25 339
en9 English Artyom123 2023-06-17 18:44:46 578
ru7 Russian Artyom123 2023-06-17 18:44:13 567
ru6 Russian Ormlis 2023-06-17 12:21:24 0 (опубликовано)
en8 English Ormlis 2023-06-17 12:20:47 0 (published)
en7 English Ormlis 2023-06-17 12:20:28 132
ru5 Russian Ormlis 2023-06-17 12:20:16 149
en6 English Ormlis 2023-06-17 11:50:26 11 Tiny change: 'd 2 hours 30 minutes to solve' -> 'd 2 hours to solve'
ru4 Russian Ormlis 2023-06-17 11:50:08 9 Мелкая правка: ' и 2 часа 30 минут на их реш' -> ' и 2 часа на их реш'
en5 English vaaven 2023-06-17 11:48:11 3 Tiny change: 'so thanks for [user:Mik' -> 'so thanks to [user:Mik'
en4 English vaaven 2023-06-17 11:38:12 1 Tiny change: 'solve them\n\n**We k' -> 'solve them.\n\n**We k'
en3 English vaaven 2023-06-17 11:37:58 6 Tiny change: 'will be a будет Div. 2 ro' -> 'will be a Div. 2 ro'
en2 English vaaven 2023-06-17 11:37:30 3 Tiny change: '</a>).\n\nМы We are hap' -> '</a>).\n\nWe are hap'
en1 English vaaven 2023-06-17 11:35:56 3875 Initial revision for English translation (saved to drafts)
ru3 Russian vaaven 2023-06-17 11:21:05 9 Мелкая правка: 'ревнования в Москве. Если вы ' -> 'ревнования. Если вы '
ru2 Russian Ormlis 2023-06-17 11:16:20 30
ru1 Russian Ormlis 2023-06-16 19:51:14 3850 Первая редакция (сохранено в черновиках)