LCA POJ 1330 Nearest Common Ancestors
Time Limit: 1000MS | Memory Limit: 10000K | |
Total Submissions: 24209 | Accepted: 12604 |
Description
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 node y if node x is in the path between the root and node y. For example, node 4 is an ancestor of node 16. Node 10 is also an ancestor of node 16. As a matter of fact, nodes 8, 4, 10, and 16 are the ancestors of node 16. Remember that a node is an ancestor of itself. Nodes 8, 4, 6, and 7 are the ancestors of node 7. A node x is called a common ancestor of two different nodes y and z if node x is an ancestor of node y and an ancestor of node z. Thus, nodes 8 and 4 are the common ancestors of nodes 16 and 7. A node x is called the nearest common ancestor of nodes y and z if x is a common ancestor of y and z and nearest to y and z among their common ancestors. Hence, the nearest common ancestor of nodes 16 and 7 is node 4. Node 4 is nearer to nodes 16 and 7 than node 8 is.
For other examples, the nearest common ancestor of nodes 2 and 3 is node 10, the nearest common ancestor of nodes 6 and 13 is node 8, and the nearest common ancestor of nodes 4 and 12 is node 4. In the last example, if y is an ancestor of z, then the nearest common ancestor of y and z is y.
Write a program that finds the nearest common ancestor of two distinct nodes in a tree.
Input
Output
Sample Input
2
16
1 14
8 5
10 16
5 9
4 6
8 4
4 10
1 13
6 15
10 11
6 7
10 2
16 3
8 1
16 12
16 7
5
2 3
3 4
3 1
1 5
3 5
Sample Output
4
3
#define N 10100
#include<iostream>
using namespace std;
#include<cstdio>
#include<cstring>
struct Edge{
int v,last;
}edge[N*];
bool visit[N],root[N];
int father[N],ance[N];
int T,n,head[N];
int x,y;
void add_edge(int u,int v,int k)
{
edge[k].v=v;
edge[k].last=head[u];
head[u]=k;
}
void input()
{
memset(root,false,sizeof(root));
memset(edge,,sizeof(edge));
memset(head,,sizeof(head));/*注意多组数据之间的衔接,把数据都清空了*/
scanf("%d",&n);
for(int i=;i<n;++i)
{
int u,v;
scanf("%d%d",&u,&v);
add_edge(u,v,i);
father[i]=i;
ance[i]=;
root[v]=true;
visit[i]=false;
}
scanf("%d%d",&x,&y);
father[n]=n;
ance[n]=;
visit[n]=false; }
int find(int k)
{
return (father[k]==k)?father[k]:father[k]=find(father[k]);
}
void tarjan(int k)
{
ance[k]=k;
for(int l=head[k];l;l=edge[l].last)
{
tarjan(edge[l].v);
father[edge[l].v]=k;
ance[edge[l].v]=k;
}
visit[k]=true;
if(k==x&&visit[y])
{
printf("%d\n",ance[find(y)]);
}
if(k==y&&visit[x])
{
printf("%d\n",ance[find(x)]);
}
}
int main()
{
scanf("%d",&T);
while(T--)
{
input();
for(int i=;i<=n;++i)
if(!root[i])
{
tarjan(i);
break;
}
}
return ;
}
LCA POJ 1330 Nearest Common Ancestors的更多相关文章
- POJ - 1330 Nearest Common Ancestors(基础LCA)
POJ - 1330 Nearest Common Ancestors Time Limit: 1000MS Memory Limit: 10000KB 64bit IO Format: %l ...
- POJ 1330 Nearest Common Ancestors / UVALive 2525 Nearest Common Ancestors (最近公共祖先LCA)
POJ 1330 Nearest Common Ancestors / UVALive 2525 Nearest Common Ancestors (最近公共祖先LCA) Description A ...
- POJ.1330 Nearest Common Ancestors (LCA 倍增)
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 ...
- POJ 1330 Nearest Common Ancestors(lca)
POJ 1330 Nearest Common Ancestors A rooted tree is a well-known data structure in computer science a ...
- POJ 1330 Nearest Common Ancestors 倍增算法的LCA
POJ 1330 Nearest Common Ancestors 题意:最近公共祖先的裸题 思路:LCA和ST我们已经很熟悉了,但是这里的f[i][j]却有相似却又不同的含义.f[i][j]表示i节 ...
- POJ 1330 Nearest Common Ancestors 【LCA模板题】
任意门:http://poj.org/problem?id=1330 Nearest Common Ancestors Time Limit: 1000MS Memory Limit: 10000 ...
- POJ 1330 Nearest Common Ancestors (LCA,dfs+ST在线算法)
Nearest Common Ancestors Time Limit: 1000MS Memory Limit: 10000K Total Submissions: 14902 Accept ...
- POJ 1330 Nearest Common Ancestors(Targin求LCA)
传送门 Nearest Common Ancestors Time Limit: 1000MS Memory Limit: 10000K Total Submissions: 26612 Ac ...
- POJ 1330 Nearest Common Ancestors LCA题解
Nearest Common Ancestors Time Limit: 1000MS Memory Limit: 10000K Total Submissions: 19728 Accept ...
随机推荐
- python3爬虫.4.下载煎蛋网妹子图
开始我学习爬虫的目标 ----> 煎蛋网 通过设置User-Agent获取网页,发现本该是图片链接的地方被一个js函数代替了 于是全局搜索到该函数 function jandan_load_im ...
- javascript中的数组去重
1.方法一:双层循环,外层循环元素,内层循环做比较,若相同则跳过,不同则加入结果集中,获取没重复的最右侧的值放入数组中 Array.prototype.distinct = function(){ v ...
- 1-编程基础及Python环境部署
目录 1 编程基础 1.1 基本概念 1.2 语言分类 1.3 高级语言的发展 2 程序 3 python的语言介绍 4 Python的解释器 5 Python版本区别 6 Python安装 6.1 ...
- Linux下的lds链接脚本详解【转】
转自:http://www.cnblogs.com/li-hao/p/4107964.html 转载自:http://linux.chinaunix.net/techdoc/beginner/2009 ...
- Linux 查看网卡流量【转】
我的系统式RHEL5. 在linux下,查看网卡流量的方法有很多.下面先记录几个,和他们的大概用法.已被以后之需. 一:iptraf 一个很不错的工具.RHEL5 iso自带有,我 ...
- selenium启动chrome模拟器模拟手机
一.如果chrome选项里边有这个模拟设备(比如iPhone 6 Plus): 1.先启动Selenium Grid, 比如命令:java -jar selenium-server-standalon ...
- spring data jpa条件分组查询及分页
原book对象 package com.shaying.domain; import javax.persistence.Column; import javax.persistence.Entity ...
- leetcode 168. Excel Sheet Column Title 171 Excel Sheet Column Number
题目 //像10进制一样进行 转换 只是要从0开始记录 class Solution { public: string convertToTitle(int n) { char a; string ...
- CGI、FastCGI和php-fpm的概念和区别
CGI是HTTP Server和一个独立的进程之间的协议,把HTTP Request的Header设置成进程的环境变量,HTTP Request的正文设置成进程的标准输入,而进程的标准输出就是HTTP ...
- 浅谈BeanUtils的拷贝,深度克隆
1.BeanUtil本地简单测试在项目中由于需要对某些对象进行深度拷贝然后进行持久化操作,想到了apache和spring都提供了BeanUtils的深度拷贝工具包,自己写了几个Demo做测试,定义了 ...