POJ.1330 Nearest Common Ancestors (LCA 倍增) 题意分析 给出一棵树,树上有n个点(n-1)条边,n-1个父子的边的关系a-b.接下来给出xy,求出xy的lca节点编号. LCA裸题,用倍增思想. 代码总览 #include <cstdio> #include <algorithm> #include <cstring> #include <cmath> #define nmax 80520 #define demen…

Nearest Common Ancestors Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 19728   Accepted: 10460 Description A rooted tree is a well-known data structure in computer science and engineering. An example is shown below:    In the figure, e…

pku 1330 Nearest Common Ancestors 题目链接: http://poj.org/problem?id=1330 题目大意: 给定一棵树的边关系,注意是有向边,因为这个WA一发.然后N个顶点给出了N-1有向边,求一对点之间的最近公共祖先 思路: 裸的离线tarjan Lca即可,但注意是有向边,需要先找出根节点,数组标记.其次要注意前向星存的时候只存一条边即可 代码: #include <iostream> #include <string.h> usi…

Nearest Common Ancestors Description A rooted tree is a well-known data structure in computer science and engineering. An example is shown below:  In the figure, each node is labeled with an integer from {1, 2,...,16}. Node 8 is the root of the tree.…

题目链接:http://poj.org/problem?id=1330 A rooted tree is a well-known data structure in computer science and engineering. An example is shown below: In the figure, each node is labeled with an integer from {1, 2,...,16}. Node 8 is the root of the tree. N…

Description A rooted tree is a well-known data structure in computer science and engineering. An example is shown below:  In the figure, each node is labeled with an integer from {1, 2,...,16}. Node 8 is the root of the tree. Node x is an ancestor of…

题目链接:http://poj.org/problem?id=1330 题意就是求一组最近公共祖先,昨晚学了离线tarjan,今天来实现一下. 个人感觉tarjan算法是利用了dfs序和节点深度的关系,大致的意思:dfs如果不递归到递归基,那么dfs就会越递归越深,这个时候深度也是相应增加的,所以这个时候任意在已经遍历过的节点中选取两个点,计算他们的lca也就相当于是用并查集求他们的root.而dfs执行到递归基,转而执行下一个分支的时候,这个时候dfs的节点应当是小于等于之前执行到递归基的节点…

给定一棵树求任意两个节点的公共祖先 tarjan离线求LCA思想是,先把所有的查询保存起来,然后dfs一遍树的时候在判断.如果当前节点是要求的两个节点当中的一个,那么再判断另外一个是否已经访问过,如果访问过的话,那么它的最近公共祖先就是当前节点祖先. 下面是tarjan离线模板: #include <cstdio> #include <cstring> #include <algorithm> using namespace std; ; struct Edge { i…

/* *********************************************** Author :kuangbin Created Time :2013-9-5 9:45:17 File Name :F:\2013ACM练习\专题学习\LCA\POJ1330_3.cpp ************************************************ */ #include <stdio.h> #include <string.h> #inclu…

题目链接:http://poj.org/problem?id=1330 Nearest Common Ancestors Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 36918   Accepted: 18495 Description A rooted tree is a well-known data structure in computer science and engineering. An example…