链接: http://acm.hdu.edu.cn/showproblem.php?pid=1151 http://acm.hust.edu.cn/vjudge/contest/view.action?cid=82834#problem/J /* ************************************************************************** //二分图匹配(匈牙利算法的DFS实现) //初始化:G[][]两边顶点的划分情况 //建立G[i][…

题意:给一个有向无环图,求出来最少需要几个士兵可以遍历所有的边. 分析:有向无环图的最小边覆盖 = 点数 - 最大匹配数 为什么是这样的公式??可以思考一下,如果这N个点之间没有边,是不是应该有N个士兵去查看,但是如果增加一条边就应该减去这条边,以此类推,公式就比较容易明白了. ******************************************************************** #include<stdio.h> #include<; ; ; j<…

题意  给定n个路口 加上一些单向路  求遍历完所有路口需要多少人  人是空降的 哪里都可以作为起点 求 最小边覆盖   (用最少的边覆盖所有的点) 也叫最小路径覆盖(更形象) 也叫二分图的最大独立集合 最小边覆盖==所有点-最大匹配数(匈牙利算法) 理解: 如果没有路  则要n个人  多一条路  则可以减一个人  . #include<bits/stdc++.h> using namespace std; #define MAXI 505 int mp[MAXI][MAXI]; int us…

http://acm.hdu.edu.cn/showproblem.php?pid=1151 Air Raid Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 7469   Accepted: 4451 Description Consider a town where all the streets are one-way and each street leads from one intersection to an…

//两道大水……哦不 两道结论题 结论:二部图的最小覆盖数=二部图的最大匹配数 有向图的最小覆盖数=节点数-二部图的最大匹配数 //hdu 1150 #include<cstdio> #include<iostream> #include<cmath> #include<algorithm> #include<cstring> #include<cstdlib> #include<queue> #include<ve…

最小点覆盖 Air Raid Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 3002    Accepted Submission(s): 1951 Problem Description Consider a town where all the streets are one-way and each street leads f…

题目: Air Raid Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 124 Accepted Submission(s): 102   Problem Description Consider a town where all the streets are one-way and each street leads from one…

Air Raid Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 6528    Accepted Submission(s): 4330 题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=1151 Description: Consider a town where all the stree…

Air RaidTime Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 4974 Accepted Submission(s): 3347 Problem DescriptionConsider a town where all the streets are one-way and each street leads from one interse…

欢迎参加——BestCoder周年纪念赛(高质量题目+多重奖励) Air Raid Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 3841    Accepted Submission(s): 2536 Problem Description Consider a town where all the streets are one-w…