線上解題系統（英語：Online Judge，縮寫OJ）是一種在演算法競賽競賽中用來測試參賽程式的線上系統

 online judge
Online Judge - Home
https://onlinejudge.org/

TCFSH CIRC Judge 適合所有中學生及初學者的 Online Judge 系統
https://judge.tcirc.tw/
ZeroJudge, An Online Judge System For Beginners
https://zerojudge.tw/


https://en.wikipedia.org/wiki/Competitive_programming