摘要:
https://www.51nod.com/onlineJudge/questionCode.html#!problemId=1737 求出树的重心,跑spfa 阅读全文
摘要:
http://poj.org/problem?id=2631 树的直径裸题 dfs/bfs均可 阅读全文
摘要:
https://www.luogu.org/problemnew/show/P2341 Tarjan 缩点 + 判断出度 阅读全文