王小二的博客

There are n houses in the village and some bidirectional roads connecting them. Every day peole always like to ask like this “How far is it if I want to go from house A to house B”? Usually it hard...

题意：求一棵树上∑i\sum i∑i号节点到它所有因子的路径和; 分析：预处理因子，LCA求树上两点距离(logn). #include <cstdio> #include <algorithm> #include <cmath> #include <queue> #include <vector> #include <cstrin...