题目:http://codeforces.com/problemset/problem/1059/E 用倍增可以在nlog内求出每个节点占用一个sequence 时最远可以向父节点延伸到的节点,对每个节点作为sequence 的最后一个元素向上延伸时,将节点的父节点属性合并(类似于并查集的操作), 存在优先队列里保证每次先操作dep最大的节点 #include<iostream> #include<cstdio> #include<cmath> #include<…

B. Appleman and Tree time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Appleman has a tree with n vertices. Some of the vertices (at least one) are colored black and other vertices are color…

题目链接:Codeforces 461B Appleman and Tree 题目大意:一棵树,以0节点为根节点,给定每一个节点的父亲节点,以及每一个点的颜色(0表示白色,1表示黑色),切断这棵树的k条边,使得树变成k+1个联通分量.保证每一个联通分量有且仅有1个黑色节点.问有多少种切割方法. 解题思路:树形dp,dp[i][0]和dp[i][1]分别表示子树一下的切割方法中,i节点所在联通块不存在黑节点和已经存在一个黑节点的方案数. #include <cstdio> #include &l…

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…

Codeforces 1129 E.Legendary Tree 解题思路: 这题好厉害,我来复读一下官方题解,顺便补充几句. 首先,可以通过询问 \(n-1​\) 次 \((S=\{1\},T=\{2\dots n\},i),i\in[2,n]​\) ,来得到以 \(1​\) 为根树的所有节点的子树大小. 然后考虑从子树大小最小的节点开始,为每一个节点找它们的儿子,由于每个节点儿子的子树大小,一定小于这个节点的子树大小,所以可以按照子树大小从小到大排序,每个节点的儿子就一定在其前面. 假设已经…

Codeforces 280C Game on tree LINK 题目大意:给你一棵树,1号节点是根,每次等概率选择没有被染黑的一个节点染黑其所有子树中的节点,问染黑所有节点的期望次数 #include<bits/stdc++.h> using namespace std; #define N 100010 int n,tot=0,head[N]={0}; struct Edge{int v,nxt;}E[N<<1]; void add(int u,int v){ E[++tot…

Split The Tree 时间限制: 1 Sec  内存限制: 128 MB 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 tree.If we delete one edge in the tree, t…

树形DP. 用倍增处理出来每个点往上能延伸出去的最远路径,nlogn 对于每个节点,如果它能被后代使用过的点覆盖,就直接覆盖,这个点就不使用,否则就ans++,让传的Max改成dp[x] #include <iostream> #include <cstdio> #include <cstring> using namespace std; typedef long long ll; ; ],f[N],head[N],to[N<<],nxt[N<<…

题目描述: Game on Tree time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Momiji has got a rooted tree, consisting of n nodes. The tree nodes are numbered by integers from 1 to n. The root has num…

Problem E. Split The Tree Problem Description You are given a tree with n vertices, numbered from 1 to n. ith vertex has a value wi We define the weight of a tree as the number of different vertex value in the tree. If we delete one edge in the tree,…