OJ学习之路

• ACM竞赛之输入输出：https://www.cnblogs.com/jiangxinnju/p/8506089.html

• awesome-algorithm: https://github.com/apachecn/awesome-algorithm

• LeetCode Online Judge: https://leetcode.com/https://leetcode-cn.com/
• 洛谷:https://www.luogu.org
• Vijos: https://vijos.org/
• Virtual Judge: https://vjudge.net/
• 牛客: https://www.nowcoder.com/
• hihocoder: http://hihocoder.com/
• cometoj: https://www.cometoj.com/
• LibreOJ: https://loj.ac/
• Universal Online Judge: http://uoj.ac/
• 青藤OJ: http://code.qingtengbc.com/
• SPOJ (Sphere Online Judge): http://www.spoj.com/
• OpenJudge: http://openjudge.cn/
• codechef: https://www.codechef.com/
• UVa Online Judge: https://uva.onlinejudge.org/
• codeforces: http://codeforces.com/
• AtCoder: https://atcoder.jp/
• 小米OJ: https://code.mi.com/site/index

高校OJ

• PKU JudgeOnline: http://poj.org/
• ZOJ: http://acm.zju.edu.cn/onlinejudge/
• HDU Online Judge System: http://acm.hdu.edu.cn/
• topcoder: https://www.topcoder.com/
• codevs: http://codevs.cn/
• 猿圈: http://www.oxcoder.com/index.htm
• 九度OJ: http://ac.jobdu.com/
• 九度OJ永久关闭声明: http://www.cskaoyan.com/thread-647811-1-1.html
• ACdream Online Judge: http://acdream.info/