Problem Description An abandoned country has n(n≤100000) villages which are numbered from 1 to n. Since abandoned for a long time, the roads need to be re-built. There are m(m≤1000000) roads to be r
链接:https://ac.nowcoder.com/acm/problem/13891 来源:牛客网 题目描述 There are many ghosts at the abandoned station on unknown railway. We mark the abandoned stations as 1,2…n according to the order. There are