Hello again Codeforces!

We are excited to invite you to the mirror contest of the VNOI Cup 2025 Final Round! Join us on Friday, July 18, 2025, at 10:00 AM GMT+7 (this is 60 minutes after the official onsite round starts) and try the same fun, yet challenging problems as our finalists!

VNOI Cup is a Competitive Programming competition hosted by VNOI (Vietnam Olympiads in Informatics community), a group of Vietnamese programmers working together to make programming competitions more fun and challenging in Vietnam. We're a non-profit organization dedicated to supporting the growth of competitive programming in Vietnam, and this competition is one of the many ways we aim to achieve that goal.

A huge shoutout to our awesome problem setters and testers! Thanks to their hard work, we have an exciting and high-quality problem set ready for you.

• Setters: Kuroni, MofK, darkkcyan, xuanquang1999, thenymphsofdelphi, TranGiaHuy, Namine, vinfat, trungnotchung, huyhasun, KaitoNMH, NguyenDangQuan, lanhf.

• Testers: awoo, _Fake4Fun, conqueror_of_tourist, McPqndq, nickbelov, Adam_GS, KIRIJIJI, bachbeo2007, bin9638, FireGhost.

The mirror contest will feature 7 to 10 problems to be solved in 5 hours. Points for problems increase with difficulty. Each problem may consist of multiple subtasks, and you only earn points for a subtask if you pass all test cases for that subtask. Penalty points are calculated as the time of the last scoring submission plus 5 minutes for each incorrect submission. Contestants are ranked by total points, with ties broken by ascending penalty points.

Links:

• Contest Link: VNOI Cup 2025 - Final Mirror. It will be opened closer to the contest date for registration.

• Past Mirrors: VNOI Cup 2024 - Final Mirror, VNOI Cup 2023 - Final Mirror.

• Detailed rules (Vietnamese).