题目来源:HDU 2444 The Accomodation of Students 题意:n个人能否够分成2组 每组的人不能相互认识 就是二分图判定 能够分成2组 每组选一个2个人认识能够去一个双人间 最多能够有几组 思路:二分图判定+最大匹配 #include <cstdio> #include <cstring> #include <vector> using namespace std; const int maxn = 550; int vis[maxn];…

本题就是先推断能否够组成二分图,然后用匈牙利算法求出最大匹配. 究竟怎样学习一种新算法呢? 我也不知道什么方法是最佳的了,由于看书本和大牛们写的匈牙利算法具体分析,看了几乎相同两个小时没看懂,最后自己直接看代码,竟然不到半个小时看懂了.然后就能够直接拿来解题啦. 比方topcoder上有这个算法的非常具体的分析.真没看懂. 代码竟然比分析更清晰了?我也不好下结论. 可是我认为基本的思想还是有作用的. 说说我对这个算法的理解吧: 1 假设二分图分为两个集合 U, V,那么从一个集合U出发 2 U的…

There are a group of students. Some of them may know each other, while others don't. For example, A and B know each other, B and C know each other. But this may not imply that A and C know each other. Now you are given all pairs of students who know…

题目链接:http://acm.split.hdu.edu.cn/showproblem.php?pid=2444 Time Limit: 5000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others) Problem Description There are a group of students. Some of them may know each other, while others don't. For ex…

题意: 有一堆的学生关系,要将他们先分成两个组,同组的人都不互不认识,如果不能分2组,输出No.若能,则继续.在两组中挑两个认识的人(每组各1人)到一个双人房.输出需要多少个双人房? 思路: 先判定是否为二分图,可以用黑白着色法(DFS或BFS都行).若是二分图,再进行匹配,用匈牙利算法,注:给的是整个图,没有区分男女,用邻接表比较好. #include <bits/stdc++.h> #define LL long long using namespace std; ; vector<…

http://acm.hdu.edu.cn/showproblem.php?pid=2444 The Accomodation of Students Time Limit:1000MS     Memory Limit:32768KB     64bit IO Format:%I64d & %I64u Submit Status Practice HDU 2444 Description There are a group of students. Some of them may know…

这是一个基础的二分图,题意比较好理解,给出n个人,其中有m对互不了解的人,先让我们判断能不能把这n对分成两部分,这就用到的二分图的判断方法了,二分图是没有由奇数条边构成环的图,这里用bfs染色法就可以判断,其次让我们求分在两部分的最大对数,这就是二分图的最大匹配问题,这里数据只有200,所以匈牙利算法求蹭广路径的办法可以解决这个问题,也相对比较容易编写. 另外一开始我链式前向星的数组开小了,G++居然返回超时,后来换了C++才RE,想到数组越界的问题,不得不说这些编译器真傲娇啊- #includ…

The Accomodation of Students Time Limit: 5000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Problem Description There are a group of students. Some of them may know each other, while others don't. For example, A and B know each o…

The Accomodation of Students Time Limit: 5000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 3775    Accepted Submission(s): 1771 Problem Description There are a group of students. Some of them may know each ot…

The Accomodation of StudentsTime Limit: 5000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 8939    Accepted Submission(s): 3925 Problem DescriptionThere are a group of students. Some of them may know each othe…

The Accomodation of Students Time Limit: 5000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 3565    Accepted Submission(s): 1659 Problem Description There are a group of students. Some of them may know each ot…

The Accomodation of Students Time Limit: 5000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 7086    Accepted Submission(s): 3167 Problem Description There are a group of students. Some of them may know each o…

首先是要构造二分图,然后二分图的最大匹配. 还有没完全证明过我的方法的正确性,但是AC了..... #include<cstdio> #include<cstring> #include<cmath> #include<vector> #include<queue> #include<algorithm> using namespace std; const int INF=0x7FFFFFFF; *+; +; int N,M; in…

传送门:http://acm.hdu.edu.cn/showproblem.php?pid=2444 题意:首先判断所有的人可不可以分成互不认识的两部分.如果可以分成 ,则求两部分最多相互认识的对数. 思路:二分图最大匹配问题.先BFS判断是否为二分图,再用匈牙利算法算最大匹配量 关于匈牙利算法:https://blog.csdn.net/CillyB/article/details/55511666 代码: #include<iostream> #include<cstdio>…

[题目链接]:pid=2444">click here~~ [题目大意]: 给出N个人和M对关系,表示a和b认识,把N个人分成两组,同组间随意俩人互不认识.若不能分成两组输出No,否则输出两组间俩人互相认识的对数 [解题思路]:   先推断是否能构成二分图,推断二分图用交叉染色法:从某个未染色的点出发把此点染成白色,该点周围的点染成黑色.黑色周围的又染成白色.若走到某个点已经染色,而且它相邻点的颜色与它一样则不是二分图,能够这样理解,染白色既增加X集合,黑色既增加Y集合,若某个点即是X集合…

题目大意:有一群人他们有一些关系,比如A认识B, B认识C, 但是这并不意味值A和C认识.现在给你所有互相认识的学生,你的任务是把所有的学生分成两个一组, 住在一个双人房里.相互认识的同学可以住在一个双人房里. 输入数据: 有n个学生 m个关系(m对是相互认识的) 接下来m行是,是m个关系. 如果能够匹配成功则输出需要双人房的个数,否则输出'No'   思路:先判断是否是个二分图,可以使用黑白染色的方法来判断.然后再进行最大匹配.   #include<stdio.h> #include<…

题目链接 题意:n个学生,m对关系,每一对互相认识的能住一个房间.问否把这些学生分成两组,要求每组的学生都互不认识.求最多须要多少个房间. 能否分成两组?也就是说推断是不是二分图,推断二分图的办法,用染色法 把初始点染成黑色,然后与之相连的染成白色,反复,使路径黑白相间, 假设当前点的颜色和与他相连点的颜色同样时,则说明这个图不是二分图 求最多须要多少个房间?也就是求最大匹配数. #include <iostream> #include <cstdio> #include <…

There are a group of students. Some of them may know each other, while others don't. For example, A and B know each other, B and C know each other. But this may not imply that A and C know each other. Now you are given all pairs of students who know…

此题就是求最大匹配.不过需要判断是否构成二分图.判断的方法是人选一点标记为红色(0),与它相邻的点标记为黑色(1),产生矛盾就无法构成二分图.声明一个vis[],初始化为-1.通过深搜,相邻的点不满足异或关系就结束.如果没被标记,就标记为相邻点的异或. #include<iostream> #include<cstdio> #include<cstring> #include<algorithm> #include<queue> using na…

hdu_2444The Accomodation of Students(二分图的判定和计算) 标签:二分图匹配 题目链接 题意: 问学生是否能分成两部分,每一部分的人都不相认识,如果能分成的话,两两认识的人可以去开房哈.求最大的开房数. 题解: 二分染色,黑白染色来看这个图可以被染成一个二分图,如果可以的话求出二分图匹配的个数即可 注意事项: dfs来染色,在求解的时候注意点的编号是从0还是从1开始的 代码: //二分图最好用链表存图 #include<cstdio> #include<…

The Accomodation of Students Time Limit: 5000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 9477    Accepted Submission(s): 4165 题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=2444 Description: There are a gro…

染色判读二分图+Hungary匹配 The Accomodation of Students Time Limit: 5000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 1705    Accepted Submission(s): 821 Problem Description There are a group of students. Some of them…

题目链接:https://vjudge.net/problem/HDU-2444 The Accomodation of Students Time Limit: 5000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 7328    Accepted Submission(s): 3270 Problem Description There are a group o…

The Accomodation of Students Time Limit: 5000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 6983    Accepted Submission(s): 3120 Problem Description There are a group of students. Some of them may know each ot…

The Accomodation of Students Time Limit: 5000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 4250    Accepted Submission(s): 1946 Problem Description There are a group of students. Some of them may know each ot…

题目链接:http://acm.split.hdu.edu.cn/showproblem.php?pid=2444 Problem Description There are a group of students. Some of them may know each other, while others don't. For example, A and B know each other, B and C know each other. But this may not imply t…

http://acm.hdu.edu.cn/showproblem.php?pid=2444 Time Limit: 5000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 7087    Accepted Submission(s): 3168 Problem Description There are a group of students. Some of the…

#include<iostream> #include<cstdio> #include<cstring> #define maxn 2010 using namespace std; int n,m,num,head[maxn],f[maxn],match[maxn],color[maxn]; struct node { int u,v,pre; }e[maxn*maxn]; void Add(int from,int to) { num++; e[num].u=fr…

图论的题目.着色原理+二分图匹配. #include <cstdio> #include <cstring> #define MAXN 205 char map[MAXN][MAXN]; int link[MAXN]; int color[MAXN]; bool visit[MAXN]; int n, m; bool dfs(int v, int col) { int i; ; i<=n; ++i) { if (map[i][v]) { if (color[i] == col…

有n个关系,他们之间某些人相互认识.这样的人有m对.你需要把人分成2组,使得每组人内部之间是相互不认识的.如果可以,就可以安排他们住宿了.安排住宿时,住在一个房间的两个人应该相互认识.最多的能有多少个房间住宿的两个相互认识. 先是要判断是否为二部图,然后求最大匹配. 学习一下模板~ #include<cstdio> #include<cstring> #include<vector> #include<algorithm> using namespace s…