Tree     Description 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. Give an integer k,for every pair (u,v) of vertices is called valid if and only if dist(u…

Tree Time Limit: 1000MS   Memory Limit: 30000K Total Submissions: 24258   Accepted: 8062 Description 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. Give an…

Tree Time Limit: 1000MS   Memory Limit: 30000K Total Submissions: 30928   Accepted: 10351 Description 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. Give an…

Tree Time Limit: 1000MS   Memory Limit: 30000K       Description 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. Give an integer k,for every pair (u,v) of ve…

[题目分析] 这貌似是做过第三道以Tree命名的题目了. 听说树分治的代码都很长,一直吓得不敢写,有生之年终于切掉这题. 点分治模板题目.自己YY了好久才写出来. 然后1A了,开心o(*￣▽￣*)ブ [代码] #include <cstdio> #include <cstring> #include <iostream> #include <algorithm> #define maxn 20005 #define inf 0x3f3f3f3f using…

Tree Time Limit: 1000MS   Memory Limit: 30000K Total Submissions: 21357   Accepted: 7006 Description 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.Give an in…

原题链接:http://poj.org/problem?id=1741 题意: 给你棵树,询问有多少点对,使得这条路径上的权值和小于K 题解: 就..大约就是树的分治 代码: #include<iostream> #include<climits> #include<cstring> #include<queue> #include<algorithm> #include<vector> #include<cstdio>…

因为该博客的两位作者瞎几把乱吹("￣︶￣)人(￣︶￣")用彼此的智慧总结出了两条全新的定理(高度复杂度定理.特异根特异树定理),转载请务必说明出处.(逃 Pass:anuonei,anuonei(臭不要脸学血小板),真的是瞎几把乱搞,我感觉大部分人都不需要这些东西吧,当初研究是因为看不懂别人的博客……还有,有些性质在dalao们看起来是相当显然,但我们真的不懂啊,讨论到深更半夜的说.定理都非严格证明,因为我们有点困了(逃).其实都是闹着玩的,主要是自己开心兴奋自豪懂了就好啦,还望大家都…

题目大意:给出一颗无根树和每条边的权值,求出树上两个点之间距离<=k的点的对数. 思路:树的点分治.利用递归和求树的重心来解决这类问题.由于满足题意的点对一共仅仅有两种: 1.在以该节点的子树中且不经过该节点. 2.路径经过该节点. 对于第一种点,我们递归处理:另外一种点.我们能够将全部子树的节点到这个子树的根节点的距离处理出来,然后排序处理出满足要求的点对的个数. 依照正常的树的结构来切割子树,这种做法的时间复杂度肯定是不好看的,为了让子树大小尽量同样.我们每次处理这个子树前找到这个子树的重心…

Description 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. Give an integer k,for every pair (u,v) of vertices is called valid if and only if dist(u,v) not e…