Codeforces Round #320 [Bayan Thanks-Round]

Revision en19, by dreamoon_love_AA, 2015-09-16 21:55:04

Hello, everyone! Codeforces Round #320 will be held at Sep/16/2015 18:00 MSK. Note that round starts in the unusual time!

The problems are from tmt514, Shik, drazil, and me(dreamoon_love_AA). Also we want to thank Zlobober for helping us preparing the round, AlexFetisov and winger for testing this round , Delinur for translating the statement into Russian, and MikeMirzayanov for Codeforces and Polygon.

This is my second time organizing a problemset for a Codeforces round (my previous round: #292). In my previous round all problems were provided by me. But I think that if problems are provided by more people, then the contest will be more interesting! So I asked my friends to help me this time. Hope everybody can have fun during the round!

Participants in each division will be given six tasks and two and a half hours for solving them (the last four problems in Div. 2 are as same as as the first four problems in Div. 1). Scoring system will be announced later closer to the start of the round.

Bayan is an Iranian software company working on large-scale web applications. It doesn't only develop the search engine, but also it holds an annual open competition Bayan Programming Contest with an on-site round in Tehran. The on-site round of 2015 became an international event with many strong participants.

Bayan has supported Codeforces on our Codeforces 5-year crowdfunding program. Thank you Bayan! This round is in your honor!

UPD 1: Due to technical reasons the round starts at 18:15 Moscow time.

UPD 2: The round will use the dynamic scoring with 250 points step.

UPD 3: Problems are ordered according to their supposed difficulty.

UPD 4: Winners!


1) Um_nik

2) Egor

3) Endagorion


1) EmaxxMaster

2) gongy

3) Irisviel_von_Einzber

UPD5: link of Editorial

Tags 320


  Rev. Lang. By When Δ Comment
en19 English dreamoon_love_AA 2015-09-16 21:55:04 73
en18 English dreamoon_love_AA 2015-09-16 21:22:42 247
en17 English dreamoon_love_AA 2015-09-16 18:06:56 75
en16 English dreamoon_love_AA 2015-09-16 18:03:56 75
en15 English dreamoon_love_AA 2015-09-16 17:59:49 4 Tiny change: 'honor!\n\nUPD 1: Due to t' -> 'honor!\n\n**UPD 1**: Due to t'
en14 English dreamoon_love_AA 2015-09-16 17:58:27 109
en13 English dreamoon_love_AA 2015-09-16 17:57:43 72
en12 English dreamoon_love_AA 2015-09-16 09:40:30 18
en11 English dreamoon_love_AA 2015-09-15 23:00:23 0 (published)
en10 English dreamoon_love_AA 2015-09-15 22:59:50 74 (saved to drafts)
en9 English dreamoon_love_AA 2015-09-15 20:40:31 0 (published)
en8 English dreamoon_love_AA 2015-09-15 20:38:59 978
en7 English dreamoon_love_AA 2015-09-15 20:37:16 508 (saved to drafts)
en6 English dreamoon_love_AA 2015-09-15 18:29:25 16
en5 English dreamoon_love_AA 2015-09-15 18:26:56 104
en4 English dreamoon_love_AA 2015-09-15 16:56:55 0 (published)
en3 English dreamoon_love_AA 2015-09-15 16:30:55 139
en2 English dreamoon_love_AA 2015-09-15 01:03:04 16
en1 English dreamoon_love_AA 2015-09-15 00:56:19 1206 Initial revision (saved to drafts)