http://codeforces.com/problemset/problem/734/E 每次操作可以把连通的同颜色的点全部换颜色,缩点,找直径,第一遍dfs找起点,第二遍dfs求直径. #include<iostream> #include<cstdio> #include<cstring> #include<algorithm> #include<vector> using namespace std; ],d[] = {},n; vec…