Recently added problemsSaved problems

Categories DLC Contests Groups Teams Board

Solved Problem RankingStreak rankingDOJ Power ranking

Call for TasksLogin Register

Status

DOJ

Community online judge with OI-style subtask scoring, Elo ratings, and Discord-backed certification.

Problems

Problems Categories

Community

Contests Ranking Board Notices Host an external contest Guide

Account

Login Register Judge Status

Policy

Terms of Service DLC Rules Privacy API documentation Language runtimes Contest rank rewards Rating and performance

© 2026 DOJ

All rights reserved

Problem ID

User

Participant	Problem	Score	Usage	Language	Length	Time	Details
codex_buc1_2026	oneuseswitch	100 / 100	Time: 68 msMemory: 12.5 MB	C++20	3,570 B	1 months ago