The Accomodation of Students Time Limit: 5000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 2244 Accepted Submission(s): 1056 Problem Description There are a group of students. Some of them may know each other,…

题意 首先判断所有的人可不可以分成两部分,每部分内的所有人都相互不认识.如果可以分成 则求两部分最多相互认识的对数. 解题 类似分成两组,同组互不相关,就可能使判断是否为二分图 能否分成两部分 则是判断是否是一个二分图.无向图G为二分图的充分必要条件是:G至少有两个顶点,且当存在回路时,其所有回路的长度均为偶数.回路就是环路,也就是判断是否存在奇数环.判断二分图方法:用染色法,把图中的点染成黑色和白色.首先取一个点染成白色,然后将其相邻的点染成黑色,如果发现有相邻且同色的点,那么就退出,可知这个…

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 <…

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…

The Accomodation of Students Time Limit: 5000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 4091    Accepted Submission(s): 1876 Problem Description There are a group of students. Some of them may know each ot…

链接: https://vjudge.net/problem/HDU-2444#author=634579757 题意: 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…

思路: 二分图判断+最大匹配模板 二分图判断的方法很好想,没有离散的基础凭空给你个图让你判断也很容易想到染色法,简单的介绍下就是用queue来做,标记一个点为x则他所有的邻点都为x',然后递归的执行下去. 接下来会面临一个比较有趣的问题,我们确定现在的图是二分图,然后我们要求它的最大匹配——这里涉及到一个很关键的问题,就是一个图我们说他自己是一个二分图,那么是他内部的一些点会分成两部分,分别写成两列变成了形式上的二分图.而我们用find求二分图的时候是分别写成两列的话是一个图的所有点,因此总数最…

//推断是否为二分图:在无向图G中,假设存在奇数回路,则不是二分图.否则是二分图. //推断回路奇偶性:把相邻两点染成黑白两色.假设相邻两点出现颜色同样则存在奇数回路. 也就是非二分图. # include <stdio.h> # include <string.h> # include <algorithm> using namespace std; int vis[210],map[210][210],cott[210]; int c[210]; int flag,…

The Accomodation of Students Time Limit:1000MS     Memory Limit:32768KB     64bit IO Format:%I64d & %I64u 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 k…

The Accomodation of Students Time Limit: 5000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 4915    Accepted Submission(s): 2260 Problem Description There are a group of students. Some of them may know each o…