两题二分图匹配的题: 1.一个农民有n头牛和m个畜栏,对于每个畜栏,每头牛有不同喜好,有的想去,有的不想,对于给定的喜好表,你需要求出最大可以满足多少头牛的需求. 2.给你学生数和课程数,以及学生上的课,如果可以做到每个学生代表不同的课程并且所有的课程都被代表输出"YES"(学生能代表一门课当且仅当他上过). 1.POJ 1274 The Perfect Stall http://poj.org/problem?id=1274 和上一题过山车一样,也是二分图匹配的. 水题. #incl…

http://poj.org/problem?id=1469 这道题我绝壁写过但是以前没有mark过二分图最大匹配的代码mark一下. 匈牙利 O(mn) #include<cstdio> #include<cstring> #include<algorithm> #include<cmath> #include<iostream> #include<queue> using namespace std; #define LL lon…

COURSES Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 21515   Accepted: 8455 Description Consider a group of N students and P courses. Each student visits zero, one or more than one courses. Your task is to determine whether it is poss…

http://poj.org/problem?id=1469 COURSES Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 19419   Accepted: 7642 Description Consider a group of N students and P courses. Each student visits zero, one or more than one courses. Your task is…

COURSES Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 18454   Accepted: 7275 Description Consider a group of N students and P courses. Each student visits zero, one or more than one courses. Your task is to determine whether it is poss…

COURSES Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 24192   Accepted: 9426 Description Consider a group of N students and P courses. Each student visits zero, one or more than one courses. Your task is to determine whether it is poss…

COURSES Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 20478   Accepted: 8056 Description Consider a group of N students and P courses. Each student visits zero, one or more than one courses. Your task is to determine whether it is poss…

[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…

COURSES Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 16877   Accepted: 6627 Description Consider a group of N students and P courses. Each student visits zero, one or more than one courses. Your task is to determine whether it is poss…

题目链接:http://poj.org/problem?id=1469 题目意思:有 N 个人,P个课程,每一个课程有一些学生参加(0个.1个或多个参加).问 能否使得 P 个课程 恰好与 P 个学生相匹配. 受之前第一道匹配题(POJ 1274 The Perfect Stall)的影响,没有仔细体会是从哪个点匹配到哪个点,这将导致Hungary() 和 dfs() 中 for 循环的约束条件,究竟是遍历课程数 P 还是 学生数N,不要搞混!其实从存储的map[i][j] 可以 知道 怎样遍历…