摘要：题目 链接：http://acm.hdu.edu.cn/showproblem.php?pid=6567 Problem Description Avin has two trees which are not connected. He asks you to add an edge betwee 阅读全文

摘要：题目 链接：https://ac.nowcoder.com/acm/contest/15644/B来源：牛客网 A gene tree is a tree showing the evolution of various genes or biological species. A gene tre 阅读全文