Hello again, Codeforces!
I am glad to invite you to Codeforces Round 1004 (Div. 1), Codeforces Round 1004 (Div. 2), at Feb/11/2025 17:35 (Moscow time).
In Division 1 you will be offered 6 problems. In Division 2 you will be offered 7 problems. One of the problems in Div.1 will be divided into 2 subtasks. Round duration is set to be 2 hours.
Also, both divisions contain at least one interactive problem(s), so be prepared for those! Guide for interactive problems
I would like to thank,
FairyWinx for dedicated coordination, a lot of problemset discussion, and suggesting one of the problems idea.
Our testers: Dart-Xeyter, I_love_kirill22, RP-1, larush, Wansur, furt1ve, Iura_Shch, SomethingNew, Gabbasov, glllll, domovonok, Error_Yuan, Monogon, triple__a, evjeny_23, Blinov_Artemii, LeoPro, antontrygubO_o, A_G, N_z__, mainyutin for testing and providing feedback.
MikeMirzayanov, KAN for Polygon and Codeforces platforms.
As always, we hope you will like the problems. Have fun!
Score Distribution:
Div. 1: 750 — 750 — 1250 — (750 + 1250) — 2000 — 3000
Div. 2: 500 — 1000 — 1250 — 1750 — 1750 — 2250 — 3000
UPD: Editorial
UPD2: We sincerely regret to inform you that we have discovered a bug in the interactor. A series of tests is currently underway to assess the full impact of this issue. Once we have the results, we will provide a detailed update. We deeply apologize for this incident and any inconvenience it may have caused.
UPD3: After the analysis, it was determined that this problem affected a small number of participants. There are no submissions that get AC with the correct interactor and erroneously received a non-AC verdict earlier. Therefore, the following decision was made:
If your solution worked with the old interactor, but does not work with the correct one and your rating has decreased, then the round will be unrated for you.
UPD4: Congratulations to the winners!
Div.1:
Also, special thanks and congratulations to rainboy for being one and only one solving problem F in division 1!
Div.2: