Apple Tree Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 26762   Accepted: 7947 Description There is an apple tree outside of kaka's house. Every autumn, a lot of apples will grow in the tree. Kaka likes apple very much, so he has been…

多次修改一棵树节点的值,或者询问当前这个节点的子树所有节点权值总和. 首先预处理出DFS序L[i]和R[i] 把问题转化为区间查询总和问题.单点修改,区间查询,树状数组即可. 注意修改的时候也要按照dfs序修改,因为你查询就是按照dfs查的,所以修改也要用dfs序修改 L[i]是唯一的. #include <cstdio> #include <cstdlib> #include <cstring> #include <cmath> #include <…

C. Propagating tree Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/383/problem/C Description Iahub likes trees very much. Recently he discovered an interesting tree named propagating tree. The tree consists of n nodes numb…

C. Propagating tree Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/383/problem/C Description Iahub likes trees very much. Recently he discovered an interesting tree named propagating tree. The tree consists of n nodes numb…

出自——博客园-zhouzhendong ~去博客园看该题解~ 题目 POJ3321 Apple Tree 题意概括 有一颗01树,以结点1为树根,一开始所有的结点权值都是1,有两种操作: 1.改变其中一个结点的权值(0变1,1变0) 2.询问子树X的节点权值和. 输入描述 一组数据. 先是一个数n,表示有n个节点. 接下去n-1行,每行表示一条边. 然后一个数m,表示有m个操作. 然后m行,每行一个字母一个数x,如果字母是Q,则是询问:否则是修改. 输出描述 每一个询问一行,表示答案. 题解…

Split The Tree 时间限制: 1 Sec  内存限制: 128 MB提交: 46  解决: 11[提交] [状态] [讨论版] [命题人:admin] 题目描述 You are given a tree with n vertices, numbered from 1 to n. ith vertex has a value wiWe define the weight of a tree as the number of different vertex value in the…

D. Alyona and a tree time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Alyona has a tree with n vertices. The root of the tree is the vertex 1. In each vertex Alyona wrote an positive intege…

http://poj.org/problem?id=3321 http://acm.hdu.edu.cn/showproblem.php?pid=3887 POJ 3321: 题意:给出一棵根节点为1的边不一定的树,然后给出问题:询问区间和 或者 节点值更新. HDU 3887: 题意:和POJ 3321的题意差不多,只不过对每个节点询问不包含该节点的区间和 思路:今天才学了下才知道有DFS序这种东西,加上树状数组处理一下区间和 和 节点更新. DFS序大概就是我们在DFS遍历一棵树的时候,在进…

题目链接: http://acm.hdu.edu.cn/showproblem.php?pid=5293 题意: 给你一些链,每条链都有自己的价值,求不相交不重合的链能够组成的最大价值. 题解: 树形dp, 对于每条链u,v,w,我们只在lca(u,v)的顶点上处理它 让dp[i]表示以i为根的指数的最大值,sum[i]表示dp[vi]的和(vi为i的儿子们) 则i点有两种决策,一种是不选以i为lca的链,则dp[i]=sum[i]. 另一种是选一条以i为lca的链,那么有转移方程:dp[i]=…

Annoying problem 题目连接: http://acm.hdu.edu.cn/showproblem.php?pid=5293 Description Coco has a tree, whose vertices are conveniently labeled by 1,2,-,n. There are m chain on the tree, Each chain has a certain weight. Coco would like to pick out some ch…