摘要：题目描述： You are given a tree (an acyclic undirected connected graph) with N nodes, and nodes numbered 1,2,3...,N. Each edge has an integer value assigne 阅读全文

摘要：题目描述： You are given a tree (an acyclic undirected connected graph) with N nodes. The tree nodes are numbered from 1 to N. We define dist(a, b) as the 阅读全文

摘要：树上的分治分两种： 点分治 和 边分治 ，点分治由于其比较稳定的复杂度，是两者中更为常用的一种。 点分治 顾名思义，就是将树用重心分割为几块，然后在每棵树中进行类似“暴力”的操作，已达到复杂度优化的作用 重心,即一棵树上的一个点，以其作为根，其最大子树大小最小的点 复杂度 考虑最坏情况，一个重心只有 阅读全文

摘要：题目描述： Give a tree with n vertices,each edge has a length(positive integer less than 1001). Define dist(u,v)=The min distance between node u and v. Giv 阅读全文

摘要：题目描述： Lady CA has a tree with n points numbered 1,2,...,n , and each edge has its weight. The unique route connecting two points is called a chain, an 阅读全文