AtCoder
AtCoder (Japanese: アトコダ) is a website that hosts online competitive programming competitions.[1]. The company was founded in 2012 and is based in Japan[2]. Similar to Codeforces and LeetCode, the website has contests, problems and a ranking system. However, it does not allow the free creation of blogs and writing of comments[3].
Contests
Contest types
AtCoder holds different types of contests on their platform[1].
AtCoder Beginner Contests (ABCs) are weekly algorithmic contests whose purpose is to teach beginners the fundamentals of competitive programming. The rated range for ABCs is 0~1999. There are no divisions for ABCs. All ABCs last 100 minutes and have 7~8 problems[1].
AtCoder Regular Contests (ARCs) are algorithmic contests which target intermediate to advanced level participants[4]. There are three divisions for ARCs, which are, in order of lowest to highest difficulty:
- The ARC--, which has a rated range of 800~2399. They have 6~7 problems and last 120 minutes.
- The ARC, which has a rated range of 1200~2799. They have 5~6 problems and also have a duration of 120 minutes.
- The ARC++, which has a rated range of 1600~2999. They have 4~5 problems and last 150 minutes[4].
Each year, AtCoder holds ARC++ 5 times, ARC 10 times and ARC-- 5 times[4].
AtCoder Grand Contests (AGCs) are algorithmic contests for very advanced problem solvers. Their rated range is 2000+. Participants who rank in the top 30 for an AGC earn GP30 scores. The 12 users with the highest algorithm GP30 scores get invited to the AtCoder World Tour Finals[5][6].
AtCoder Weekday Contests (AWCs) are algorithmic contests that are currently in beta and are held experimentally on weekdays[7]
AtCoder Heuristic Contests (AHCs) are heuristic contests; they only have one problem and participants are given a long time to optimise their solution to it. Participants who rank in the top 30 for an AHC earn GP30 scores. The 12 users with the highest heuristic GP30 scores get invited to the AtCoder World Tour Finals.[5][6]
Contest rules
Every algorithmic AtCoder contest is full-feedback. When a problem is solved, the user who solved it gains a score for the problem. Competitors are ranked first by total scores, then by penalties. The penalties are computed as (the time you spend to get your current score) + (5 minutes) * (the number of incorrect attempts).[7]
References
- ↑ 1.0 1.1 1.2 Inc, AtCoder (2016-07-13). "Welcome to AtCoder!". AtCoder. Retrieved 2026-03-22.
- ↑ "AtCoder 2026 Company Profile: Valuation, Funding & Investors | PitchBook". pitchbook.com. Retrieved 2026-03-22.
- ↑ Inc, AtCoder (2026-03-20). "AtCoder". AtCoder. Retrieved 2026-03-22.
- ↑ 4.0 4.1 4.2 Inc, AtCoder (2026-02-20). "Changes to ARC in 2026". AtCoder. Retrieved 2026-03-22.
- ↑ 5.0 5.1 Inc, AtCoder (2026-01-16). "Announcement of AtCoder World Tour Finals 2027". AtCoder. Retrieved 2026-03-22.
- ↑ 6.0 6.1 "AtCoder レースランキング・AtCoder World Tour Finals 開催決定！". プレスリリース・ニュースリリース配信シェアNo.1｜PR TIMES (in 日本語). 2017-12-26. Retrieved 2026-03-22.
- ↑ 7.0 7.1 Inc, AtCoder. "AtCoder Weekday Contest 0001 Beta". AtCoder. Retrieved 2026-03-22.
This article "AtCoder" is from Wikipedia. The list of its authors can be seen in its historical and/or the page Edithistory:AtCoder. Articles copied from Draft Namespace on Wikipedia could be seen on the Draft Namespace of Wikipedia and not main one.
