传送门 Closest Common Ancestors Time Limit: 2000MS   Memory Limit: 10000K Total Submissions: 14915   Accepted: 4745 Description Write a program that takes as input a rooted tree and a list of pairs of vertices. For each pair (u,v) the program determines…

[题意] 给出一棵树和多组查询,求以每个节点为LCA的查询数有多少? [错误点] ①读入的时候,注意它的空格是随意的呀!一开始不知道怎么弄,后来看了DISCUSS区大神的话: 询问部分输入: scanf("%d",&m);for(int i=0;i<m;i++){scanf(" (%d %d)",&a,&b);} 注意scanf(" 这里有一个空格 ②多组数据啊!注意这句话:The input file contents se…

非常裸的模版题,只是Tarjan要好好多拿出来玩味几次 非常有点巧妙呢,tarjan,大概就是当前结点和它儿子结点的羁绊 WA了俩小时,,,原因是,这个题是多数据的(还没告诉你T,用scanf!=EOF来控制结束),更重要的是和这个和Codeforces不一样,Codeforces的多组数据好像会又一次開始程序似的,不用在程序里面写清零,但这个题是多数据用EOF来控制输入的,多数据在一个文件中都一次输进去了,所以要memset btw,加上一点memset代码,多了700B代码... #incl…

题目链接: http://poj.org/problem?id=1470 题意: 给定若干有向边,构成有根数,给定若干查询,求每个查询的结点的LCA出现次数. 分析: 还是很裸的tarjan的LCA. 这题我真的要吐槽!!调试了好久啊!!不是MLE就是RE.... 查询数量没给,所以要用矩阵来存,这样还可以避免重复. 给边的时候不知道会不会有重复的点,所以讲道理应该用vector保存. getchar...我不知道为什么会RE... 其实ance数组可以不用的,只要每次处理子树的时候pa[v]…

LCA问题,用了离线的tarjan算法.输入输出参考了博客http://www.cnblogs.com/rainydays/archive/2011/06/20/2085503.htmltarjan算法是用了dfs+并查集的方式做的.这里输入输出有个不错的地方,就是用scanf("%[^0-9]", st);跳过非数字.里面用数组g来表示多维的树,还用并查集的id数组的-1来表示是否访问. #include <iostream> #include <cstdio>…

任意门:http://poj.org/problem?id=1470 Closest Common Ancestors Time Limit: 2000MS   Memory Limit: 10000K Total Submissions: 22519   Accepted: 7137 Description Write a program that takes as input a rooted tree and a list of pairs of vertices. For each pa…

Closest Common Ancestors Time Limit: 2000MS   Memory Limit: 10000K Total Submissions: 13372   Accepted: 4340 Description Write a program that takes as input a rooted tree and a list of pairs of vertices. For each pair (u,v) the program determines the…

POJ 1470 Closest Common Ancestors(最近公共祖先 LCA) Description Write a program that takes as input a rooted tree and a list of pairs of vertices. For each pair (u,v) the program determines the closest common ancestor of u and v in the tree. The closest co…

Closest Common Ancestors Time Limit: 2000MS   Memory Limit: 10000K Total Submissions: 13370   Accepted: 4338 Description Write a program that takes as input a rooted tree and a list of pairs of vertices. For each pair (u,v) the program determines the…

Closest Common Ancestors Time Limit: 2000MS   Memory Limit: 10000K Total Submissions: 15446   Accepted: 4944 Description Write a program that takes as input a rooted tree and a list of pairs of vertices. For each pair (u,v) the program determines the…

Closest Common Ancestors Time Limit: 10 Seconds      Memory Limit: 32768 KB Write a program that takes as input a rooted tree and a list of pairs of vertices. For each pair (u,v) the program determines the closest common ancestor of u and v in the tr…

传送门 Closest Common Ancestors Time Limit: 2000MS   Memory Limit: 10000K Total Submissions: 17306   Accepted: 5549 Description Write a program that takes as input a rooted tree and a list of pairs of vertices. For each pair (u,v) the program determines…

Closest Common Ancestors Time Limit: 2000ms Memory Limit: 10000KB This problem will be judged on PKU. Original ID: 147064-bit integer IO format: %lld      Java class name: Main     Write a program that takes as input a rooted tree and a list of pairs…

Closest Common Ancestors Time Limit: 2000MS   Memory Limit: 10000K Total Submissions: 20804   Accepted: 6608 Description Write a program that takes as input a rooted tree and a list of pairs of vertices. For each pair (u,v) the program determines the…

Language: Default Closest Common Ancestors Time Limit: 2000MS   Memory Limit: 10000K Total Submissions: 24653   Accepted: 7648 Description Write a program that takes as input a rooted tree and a list of pairs of vertices. For each pair (u,v) the prog…

Description Write a program that takes as input a rooted tree and a list of pairs of vertices. For each pair (u,v) the program determines the closest common ancestor of u and v in the tree. The closest common ancestor of two nodes u and v is the node…

Nearest Common Ancestors Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 18136   Accepted: 9608 Description A rooted tree is a well-known data structure in computer science and engineering. An example is shown below: In the figure, each…

[知识点:离线算法&在线算法] 一个离线算法,在开始时就需要知道问题的所有输入数据,而且在解决一个问题后就要立即输出结果. 一个在线算法是指它可以以序列化的方式一个个的处理输入,也就是说在开始时并不需要已经知道所有的输入. [倍增-在线算法] 水题……这道题范围卡得很紧…数组少了一位就会WA. #include<iostream> #include<cstdio> #include<cstring> #include<algorithm> #incl…

[题目链接] 点击打开链接 [算法] 离线tarjan求最近公共祖先 [代码] #include <algorithm> #include <bitset> #include <cctype> #include <cerrno> #include <clocale> #include <cmath> #include <complex> #include <cstdio> #include <cstdli…

题目链接:http://poj.org/problem?id=1470 Write a program that takes as input a rooted tree and a list of pairs of vertices. For each pair (u,v) the program determines the closest common ancestor of u and v in the tree. The closest common ancestor of two n…

Write a program that takes as input a rooted tree and a list of pairs of vertices. For each pair (u,v) the program determines the closest common ancestor of u and v in the tree. The closest common ancestor of two nodes u and v is the node w that is a…

Write a program that takes as input a rooted tree and a list of pairs of vertices. For each pair (u,v) the program determines the closest common ancestor of u and v in the tree. The closest common ancestor of two nodes u and v is the node w that is a…

http://poj.org/problem?id=1470 Time Limit: 2000MS   Memory Limit: 10000K Total Submissions: 20830   Accepted: 6617 Description Write a program that takes as input a rooted tree and a list of pairs of vertices. For each pair (u,v) the program determin…

[题目大意] 给你N个点的无向图 (1 <= N <= 15,000),记为:1…N.图中有M条边 (1<=M<=30,000) ,第j条边的长度:d_j (1<=d_j <=1,000,000,000).现在有 K个询问 (1 < = K < = 15,000), 每个询问的格式是:A B,表示询问从A点走到B点的所有路径中,最长的边最小值是多少? [思路] 显然,最小的最长边应该在MST上.先跑出MST,然后对于每个询问跑LCA,在跑LCA的过程中顺便处…

[题目描述:] 小仓鼠的和他的基(mei)友(zi)sugar住在地下洞穴中,每个节点的编号为1~n.地下洞穴是一个树形结构.这一天小仓鼠打算从从他的卧室(a)到餐厅(b),而他的基友同时要从他的卧室(c)到图书馆(d).他们都会走最短路径.现在小仓鼠希望知道,有没有可能在某个地方,可以碰到他的基友? 小仓鼠那么弱,还要天天被zzq大爷虐,请你快来救救他吧! [输入格式:] 第一行两个正整数n和q,表示这棵树节点的个数和询问的个数. 接下来n-1行,每行两个正整数u和v,表示节点u到节点v之间有…

[题目大意]给出一张存在哈密顿回路的无向图,判断是否是平面图.[思路]首先平面图的一个性质:边数<=点数*3-6因为存在哈密顿回路,可以将回路看作是一个圆,考量不再哈密顿回路中的边.如果两天边相交(判断相交可以随意yy一下),那么必然一条在圆内一条在圆外,显然是2-SAT. #include<iostream> #include<cstdio> #include<cstring> #include<algorithm> #include<vect…

<题目链接> 题目大意:给你一棵树,然后进行q次询问,然后要你统计这q次询问中指定的两个节点最近公共祖先出现的次数. 解题分析:LCA模板题,下面用的是离线Tarjan来解决.并且为了代码的简洁,本代码用的是vector存图. #include<iostream> #include<cstdio> #include<cstring> #include<vector> using namespace std; ; vector<int>…

版权声明:本文为博主原创文章,未经博主同意不得转载. https://blog.csdn.net/u013912596/article/details/35311489 题目链接:http://poj.org/problem?id=1470 题目大意:给出一棵树.再给出若干组数(a,b),输出节点a和节点b的近期公共祖先(LCA) 就是非常裸的LCA.可是我用的是<挑战程序设计竞赛>上的"基于二分搜索的算法求LCA",我看网上用的都是tarjan算法.可是我的代码不知道为什…

Tarjan算法的详细介绍,请戳: http://www.cnblogs.com/chenxiwenruo/p/3529533.html #include <iostream> #include <stdio.h> #include <string.h> #include <algorithm> #include <string> #include <vector> /* AC 一开始读取数据的方式并不好,运行900多ms. 后来参照…

午时刷题,难甚,遂小憩于桌上,惊醒,于梦中有所得,虽大声曰:吾已得tarjan之奥秘! 关于tarjan算法,其实就是一个递归加并查集的应用. 大致代码: #include<bits/stdc++.h> using namespace std; int find(int x){ .... } void join(int x,int y) { .... } void dfs(int x) { int len=v[x].size(); ; i<len; i++) //遍历x的子节点 { df…