题意: 给你一颗N个节点的树,节点编号1到N.1总是节点的根.现在有两种操作: M v: 标记节点v Q v: 求出离v最近的标记的相邻节点.根节点一开始就标记好了. 现在给一系列操作,求出所有Q操作结果的和. 思路: 最坏情况下为整棵树成为一条链,单纯使用并查集(无压缩)查询复杂度最坏1e10.单纯使用并查集也能过. 正解应该是将查询存下来,存下每次Q操作的查询时间和查询结点,用qt和qv数组存储.另外设置mark数组存储这个结点被染色的最快时间.然后我们倒着进行查询操作,当当前查询的结点最早…

https://vjudge.net/problem/Aizu-2170 并查集用于管理元素分组情况. 建树pre[]记录父节点,一开始只有结点1被标记了,所以find()最终得到的根都是1. 如果遇到M操作,即将树断开(很神奇的操作). #include<iostream> #include<cstdio> #include<queue> #include<cstring> #include<algorithm> #include<cma…

http://acm.hust.edu.cn/vjudge/problem/viewProblem.action?id=45522 给定一棵树的n个节点,每个节点标号在1到n之间,1是树的根节点,有如下两种操作: M v :把编号为v的节点标记. Q v :查询与v节点距离最近的被标记的点的编号.最初只有根节点被标记. 输入n-1个数表示,每一个数是当前第i个数的父节点,输出对于每个查询得到标号的总和. 并查集与树的结合,在输入的时候就可以根据父节点的关系建立并查集,1的父亲是1. 还有把编号为…

题意: 有一个树,有些节点染色,每次有两种操作,第一,统计该节点到离它最近的染色父亲结点的的号码(Q),第二,为某一个节点染色(M),求第一种操作和. 输入: 输入由多个数据集组成.每个数据集都有以下格式:输入的第一行包含两个整数N和Q,分别表示树T中的节点数和操作数.这些数字满足以下条件:1≤N≤100000和1≤Q≤100000.下面的N-1行,每行包含一个整数pi(i = 2,...,N),它表示第i个节点的父节点的编号.接下来的Q行按顺序包含操作.每个操作都格式化为“M v”或“Q v”…

Connections in Galaxy War Time Limit:3000MS     Memory Limit:32768KB     64bit IO Format:%lld & %llu Submit Status Practice ZOJ 3261 Appoint description:  Description In order to strengthen the defense ability, many stars in galaxy allied together an…

Benny has a spacious farm land to irrigate. The farm land is a rectangle, and is divided into a lot of samll squares. Water pipes are placed in these squares. Different square has a different type of pipe. There are 11 types of pipes, which is marked…

Problem Description Today is Ignatius' birthday. He invites a lot of friends. Now it's dinner time. Ignatius wants to know how many tables he needs at least. You have to notice that not all the friends know each other, and all the friends do not want…

本文来自:http://www.cnblogs.com/Findxiaoxun/p/3428516.html 写得很好,一看就懂了. 在这里就复制了一份. LCA问题: 给出一棵有根树T,对于任意两个结点u,v求出LCA(T, u, v),即离根最远的结点x,使得x同时是u和v的祖先. 把LCA问题看成询问式的:给出一系列询问,程序应当对每一个询问尽快做出反应. 对于这类问题有两种解决方法;一是用比较长的时间做预处理,但是等信息充足以后每次回答询问只需要用比较少的时间.这样的算法叫做在线算法.…

C. The Labyrinth 题目连接: http://www.codeforces.com/contest/616/problem/C Description You are given a rectangular field of n × m cells. Each cell is either empty or impassable (contains an obstacle). Empty cells are marked with '.', impassable cells are…

How Many Tables 题目链接: http://acm.hust.edu.cn/vjudge/contest/123393#problem/C Description Today is Ignatius' birthday. He invites a lot of friends. Now it's dinner time. Ignatius wants to know how many tables he needs at least. You have to notice that…