Online judges
The 18 judges in judges.yaml, the registry every judge link refers to: per-problem links (problems) and contest-level judge pages (contest pages, sources with role judge_page). A closed judge's pages survive only in Wayback snapshots taken before the closing date.
| id | judge | status | problems | contest pages | offers | notes |
|---|---|---|---|---|---|---|
| kattis | Kattis | active | 2929 | 332 | statements · submissions | Problem-source pages list a contest's problems; short names are the problem ids. |
| livearchive | ICPC Live Archive | active | 2194 | 266 | statements · submissions | Formerly icpcarchive.ecs.baylor.edu (same ids); category pages hold one contest each. |
| baekjoon | Baekjoon Online Judge | closed 2026-04-28 | 5973 | 839 | statements | Service ended 2026-04-28 (서비스 종료); pages survive only in Wayback snapshots before that date. |
| codeforces | Codeforces Gym | active | 2202 | 362 | statements · submissions | Gym pages need a login to view; ids are gym number (+ problem letter). |
| qoj | QOJ / Universal Cup | active | 0 | 0 | statements · submissions | |
| aoj | Aizu Online Judge (AOJ) | active | 264 | 27 | statements · submissions | Hosts every ICPC Asia Japan regional 1998-2024 (one 'challenge day' per year, ids 49-325) plus Japan Domestic qualifiers (ICPC/Prelim, not catalogue) and JAG practice contests (not catalogue). Old judgeapi.u-aizu.ac.jp returns 410 Gone; the live JSON API is https://onlinejudge.u-aizu.ac.jp/api/ (e.g. /api/challenges, /api/challenges/cl/ICPC/Regional, /api/problems?page=0&size=N). 2025 Yokohama regional not yet listed as of 2026-11-03. |
| beecrowd | beecrowd (ex URI Online Judge) | active | 0 | 0 | statements · submissions | BLOCKED: every page (contests, problems) returns a Cloudflare "Just a moment" JS challenge (HTTP 403) to curl and to WebFetch; not bypassed per rules. Known to host Maratona de Programacao (brazil-first-phase / brazil) problem sets as problems 1xxx-3xxx with a "Maratona" source and past-contest pages, but nothing could be enumerated this run. |
| codechef | CodeChef | active | 229 | 21 | statements · submissions | Hosts ICPC India (Asia West) regionals: online first rounds / preliminaries 2010-2016 and onsite mirror/replay contests 2012-2019 and 2025. Public APIs: past list https://www.codechef.com/api/list/contests/past?sort_by=START&sorting_order=desc&offset=N&mode=all (20/page, 2198 contests back to 2009; no search param) and per-contest https://www.codechef.com/api/contests/{code} (problems with names). 2020-2024 ICPC India rounds were NOT found in the past-contest API (codes unknown; probably not in the public list). Replay/mirror contests contain the official onsite problem set. |
| dmoj | DMOJ | active | 88 | 9 | statements · submissions | Canadian judge. HTML is behind Cloudflare for curl but the public API works: https://dmoj.ca/api/v2/problems?page=N (5275 problems) and /api/v2/contests (506 contests, no ICPC mirrors). Problem group "ICPC" + name prefix "ICPC <contest> <letter> - <title>" gives complete sets for ECNA 2016, NAQ 2016, PACNW 2016, SWERC 2017, ECNA 2005, CTU Open 2017/2018, partial ECNA 2000, NEERC 2010 and singles. No contest pages; the "contest_url" is a problem-list search. |
| eolymp | Eolymp (ex e-olymp) | active | 0 | 12 | statements · submissions | Public REST API https://api.eolymp.com/spaces/00000000-0000-0000-0000-000000000000/contests?size=100&offset=N lists 1317 public contests (name, startsAt, problemCount). Contest problem lists and statements require sign-in (API /contests/{id}/problems -> unauthenticated), so matches are by contest name/date only. Hosts the Ukrainian ICPC chain: UCPC Stage I (1/8 final, Sept/Oct), Stage II (1/4 final = catalogue ukraine-YYYY), Stage III (1/2 final, Dec) 2020-2026, plus 2012-2014-era mirrors of many regionals (GNY/ECNA/MCPC/NCNA/RMC/SCUSA/NAQ 2013, NWERC 2013, BAPC 2013, CTU Open 2013, NCPC 2013, SEERC 2003/2009/2013, NEERC 2006/2011, Latin America 2012/2013, Tokyo 2012, Aizu 2013, Tehran 2007, Maratona 2010) and NERC 2019/2022, SWERC 2011/2020. Azerbaijan contests on eolymp are school olympiads/qualifications, not the ICPC regional. |
| hdu | HDU Online Judge (acm.hdu.edu.cn) | active | 164 | 14 | statements · submissions | GBK-encoded. STD contest list https://acm.hdu.edu.cn/contests/contest_list.php?page=N&type= (36 pages, 618 contests). Public 重现赛/题目重现 re-runs of China regionals 2013-2017 (Hangzhou/Chengdu/Nanjing 2013, Anshan/Beijing/Guangzhou 2014, Shenyang/Changchun/Hefei/Shanghai 2015, Shenyang/Dalian/Qingdao 2016, Shenyang 2017); 'Online' preliminaries are Private (login). contest_show.php lists problems for ended public contests without login; /contest/problems?cid= redirects. Regional sets also live in the main archive (problems 4xxx-6xxx, Source field) but source search returned nothing. Server flaky (connection resets). |
| luogu | Luogu 洛谷 (Luògǔ) | active | 354 | 32 | statements · submissions | Official-team (洛谷官方团队) 重现赛 (chóngxiànsài, replay) mirrors of ICPC China regionals / EC-Final with original data (credit 计蒜客 Jisuanke), run 2023-2026 and ongoing (new one roughly weekly). Contest list JSON is embedded in <script id=lentille-context> on /contest/list?page=N (1404 contests, 71 pages); contest pages embed contestProblems with pid (P1xxxx) and titles. Some mirrors (Nanjing 2022-24, Jinan 2023, Kunming inv.) carry Chinese-translated titles. Statements viewable without login; submitting needs account. |
| nowcoder | NowCoder 牛客竞赛 (Niúkè, 'cow guest') | active | 142 | 11 | statements · submissions | Official judge for the 45th/46th ICPC China regionals (2020 Jinan, Nanjing, Shanghai, Kunming; 2021 Shenyang, Shanghai, Kunming) and 重现赛 mirrors of 2018 EC-Final, 2019 EC-Final/Shanghai, 2020 Shenyang. Problem list JSON: https://ac.nowcoder.com/acm/contest/problem-list?id={id} (public, no login). Contest search https://ac.nowcoder.com/acm-heavy/acm/contest/search?searchName=... is capped at ~10-15 hits; ended-contest list /acm/contest/vip-end-index?topCategoryFilter=13&categoryFilter=22 (比赛真题 'real past contests') is mostly provincial contests. Problem statements need login? -> statements render for anonymous users on /acm/contest/{id}/{letter}. |
| omegaup | omegaUp | active | 66 | 6 | statements · submissions | Mexican judge used by ICPC Mexico. /api/contest/list/ returns only current contests to anonymous callers (no past list), /api/contest/problems/ needs login; /api/contest/publicDetails/?contest_alias=X works for public contests. /api/problem/list/?tag[]=problemTagICPC lists 41 public problems incl. the full ICPCMX2021 set (alias prefix ICPCMX2021-). Contest "Concurso Regional #ICPCMX2021" (alias ICPCMX2021, 2022-04-02) confirmed. Other years' aliases not guessable; TCMM/Gran Premio contests not found. |
| pintia | PTA 拼题A (Pīntí A, 'puzzle-piece problem A', pintia.cn) | active | 0 | 0 | submissions | BLOCKER: problem-set listing (/api/problem-sets, ListVisibleProblemSets) and problem-set metadata (/api/problem-sets/{id}) return 401 USER_NOT_LOGGED_IN; only /api/problem-sets/always-available (23 textbook sets) and /api/competitions/public (46 XCPC scoreboard objects, 2024-2026, mostly CCPC/provincial + ICPC EC online prelims) are public. Front-end API table recovered from static.pintia.cn/sparkling-daydream chunks. No ICPC regional problem-set ids could be confirmed from public pages, so no candidates recorded. |
| timus | Timus Online Judge | active | 101 | 11 | statements · submissions | Ural FU judge. Past-contest archive at /archive.aspx (110 contests, each with a problem "space"); the main problem set (/problemset.aspx?space=1&page=all, 1243 problems) has a Source column naming the origin contest (NEERC 2000-2002 finals, NEERC Central/Northern/Eastern subregionals). ICPC-relevant: NEERC Eastern (Ural) subregional 2006-2014 live online versions, Central subregional (Rybinsk) 2001-2003, plus NEERC 2000-2002 and Central 2000 / Northern 2001 problems in the main set. Since 2015 Timus only hosts the Ural *qualifier* rounds, not the regional itself. |
| ucup | Universal Cup judge (contest.ucup.ac, UOJ-based) | active | 0 | 0 | statements · submissions | Reachable (200). Lists only Universal Cup stages ('The Nth Universal Cup. Stage K: Grand Prix of X'); these are Open-Cup-style rounds that often reuse ICPC regional sets (e.g. Stage 6 'Grand Prix of Shenyang' = 2025 Shenyang regional) but per brief are not catalogue contests, so no candidates recorded. The ICPC-named mirrors live on qoj.ac, not here. |
| vjudge | Virtual Judge (vjudge.net) | active | 0 | 0 | statements · submissions | BLOCKED: vjudge.net (/, /contest, /contest/data API) returns 403 Cloudflare challenge to curl and WebFetch from this network. Not bypassed. No candidates recorded. |