码迷,mamicode.com
首页 > 其他好文 > 详细

POJ1466_Girls and Boys(二分图/最大独立集=N-最大匹配)

时间:2014-07-27 11:21:32      阅读:212      评论:0      收藏:0      [点我收藏+]

标签:

解题报告

http://blog.csdn.net/juncoder/article/details/38160591

题目传送门

题意:

求满足条件的最大集合:集合内任何两个人都没有浪漫关系

思路:

POJ2771一样的题,变的简单多了。POJ2771解题报告

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
int n,mmap[550][550],pre[550],vis[550];
int dfs(int x)
{
    for(int i=0; i<n; i++) {
        if(!vis[i]&&mmap[x][i]) {
            vis[i]=1;
            if(pre[i]==-1||dfs(pre[i])) {
                pre[i]=x;
                return 1;
            }
        }
    }
    return 0;
}
int main()
{
    int i,j,a,b,k;
    while(~scanf("%d",&n)) {
        memset(mmap,0,sizeof(mmap));
        memset(pre,-1,sizeof(pre));
        for(i=1; i<=n; i++) {
            scanf("%d: (%d) ",&a,&k);
            for(j=1; j<=k; j++) {
                scanf("%d",&b);
                mmap[a][b]=1;
            }
        }
        int ans=0;
        for(i=0; i<n; i++) {
            memset(vis,0,sizeof(vis));
            ans+=dfs(i);
        }
        printf("%d\n",n-ans/2);
    }
    return 0;
}

Girls and Boys
Time Limit: 5000MS   Memory Limit: 10000K
Total Submissions: 10348   Accepted: 4608

Description

In the second year of the university somebody started a study on the romantic relations between the students. The relation "romantically involved" is defined between one girl and one boy. For the study reasons it is necessary to find out the maximum set satisfying the condition: there are no two students in the set who have been "romantically involved". The result of the program is the number of students in such a set.

Input

The input contains several data sets in text format. Each data set represents one set of subjects of the study, with the following description: 

the number of students 
the description of each student, in the following format 
student_identifier:(number_of_romantic_relations) student_identifier1 student_identifier2 student_identifier3 ... 
or 
student_identifier:(0) 

The student_identifier is an integer number between 0 and n-1 (n <=500 ), for n subjects.

Output

For each given data set, the program should write to standard output a line containing the result.

Sample Input

7
0: (3) 4 5 6
1: (2) 4 6
2: (0)
3: (0)
4: (2) 0 1
5: (1) 0
6: (2) 0 1
3
0: (2) 1 2
1: (1) 0
2: (1) 0

Sample Output

5
2


POJ1466_Girls and Boys(二分图/最大独立集=N-最大匹配)

标签:

原文地址:http://blog.csdn.net/juncoder/article/details/38160591

(0)
(0)
   
举报
评论 一句话评论(0
登录后才能评论!
© 2014 mamicode.com 版权所有  联系我们:gaon5@hotmail.com
迷上了代码!