http://codeforces.com/contest/348/problem/B 题意:给一棵树,每个叶子结点有w[i]个苹果,每个子树的苹果数量为该子树所有叶子结点苹果数量之和,要使得每个结点的各个子树苹果数量相等,求至少需要拿走的苹果数量. 思路:一开始以为只要使得所有子树之和相同就行了. void dfs(int u, int fa) { , mi = INF; for(int i = head[u]; ~i; i = edge[i].nxt) { int v = edge[i].v…

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 carefully nurturing the big apple tree. The tree has N forks which are connected by branches.…

Apple Tree Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 25904   Accepted: 7682 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…

题目链接 Apple Tree Time Limit: 1000MS Memory Limit: 65536K Total Submissions: 9692 Accepted: 3217 Description Wshxzt is a lovely girl. She likes apple very much. One day HX takes her to an apple tree. There are N nodes in the tree. Each node has an amou…

题目链接 Problem Description There is a tree with n nodes, each of which has a type of color represented by an integer, where the color of node i is ci. The path between each two different nodes is unique, of which we define the value as the number of di…

题目大概说给一棵树,树上结点都有颜色(1到60),进行下面两个操作:把某结点为根的子树染成某一颜色.询问某结点为根的子树有多少种颜色. 子树,显然DFS序,把子树结点映射到连续的区间.而注意到颜色60种,这样就可以用一个64位整型去表示颜色的集合,然后就是在这个连续区间中用线段树成段更新颜色集合和区间查询颜色集合了. #include<cstdio> #include<cstring> using namespace std; #define MAXN 500000 struct…

题目大意:对树进行m次操作,有两类操作,一种是改变一个点的权值(将0变为1,1变为0),另一种为查询以x为根节点的子树点权值之和,开始时所有点权值为1. 分析: 对树进行dfs,将树变为序列,记录每个点进栈出栈的时间戳作为其对应区间的左右端点,那么其子节点对应区间必在该区间内,对这段区间求和即可,用树状数组进行修改与求和. 代码: program apple; type point=^node; node=record x:longint; next:point; end; var a:..]o…

http://acm.hust.edu.cn/vjudge/problem/viewProblem.action?id=10486 题意:一颗有n个分支的苹果树,根为1,每个分支只有一个苹果,给出n-1个分支的关系和给出m个操作,Q x表示询问x的子树(包括x)苹果的数量,C x表示若分支x上有苹果,则摘下来,若没有则会生出一个,输出每个询问的值. DFS序 每个子树对应的孩子节点包括根用dfs序存在连续区间中,用树状数组维护区间 //#pragma comment(linker, "/STAC…

传送门 •题意 给你一颗 n 个节点的树,每个节点被染上了颜色: 有 m 次操作,每次操作的类型有两种 1 v c : 将以 v 为根的子树的结点全部涂成 c 2 v : 询问以 v 为根的子树的结点中不同颜色的数量 •题解 因为操作的是某个节点对应的子树,所以我们可以通过DFS序获得每一个结点的子树区间. 之后我们就将这个树形的问题转化成了一个线性区间的问题: 然后,就可以用线段树来维护(区间更新,区间查询): 求解某个区间不同颜色的个数要怎么办呢? 刚开始,我在线段树中定义了一个 $set$…

题目链接:http://codeforces.com/problemset/problem/682/C 题意:如果点v在点u的子树上且dist(u,v)>a[v]则u和其整个子树都将被删去,求被删去的点数. 思路:1为根节点,从1开始DFS遍历,记录距离dis为到祖宗节点的最大距离. #include<bits/stdc++.h> using namespace std; typedef long long ll; const int N=1e5+5; int a[N],num[N],a…