poj 1466 HDU 1068 Girls and Boys （最大独立集）

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.

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.

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

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

5
2

Southeastern Europe 2000

一群男女搞暧昧，求一个最大的集合，元素满足任意两个元素都不暧昧。
 额，贴完去吃饭饭~~：

/*=============================================================================
#
#      Author: liangshu - cbam 
#
#      QQ : 756029571 
#
#      School : 哈尔滨理工大学 
#
#      Last modified: 2015-08-27 17:19
#
#     Filename: C.cpp
#
#     Description: 
#        The people who are crazy enough to think they can change the world, are the ones who do ! 
=============================================================================*/
#

#include<iostream>    
#include<sstream>    
#include<algorithm>    
#include<cstdio>    
#include<string.h>    
#include<cctype>    
#include<string>    
#include<cmath>    
#include<vector>    
#include<stack>    
#include<queue>    
#include<map>    
#include<set>    
using namespace std;
const int INF=800; 
int n;
int from[INF],tot;
bool use[INF];
vector<int>G[INF];
bool match(int x)
{
     for(int i=0;i<G[x].size();i++)
    {
         if(!use[G[x][i]])
        {
             use[G[x][i]]=1;
            if(from[G[x][i]]==-1||match(from[G[x][i]]))
            {
                 from[G[x][i]]=x;
                return 1;
            }
        }
    }
    return 0;
}

int hungary( )
{
     tot=0;
    memset(from,255,sizeof(from));
    for(int i=0;i<n;i++)
    {
         memset(use,0,sizeof(use));
        if(match(i))
           {
               ++tot;
           }
    }
    return tot;
}

int main(){
    int x, y;
    while(cin>>n){
    for(int i = 0; i < n; i++){
        scanf("%d: (%d)",&x, &y);
        for(int j = 0; j < y; j++){
            int a;
            scanf("%d",&a);
            G[x].push_back(a);
        }
    }
        cout<<n - hungary() / 2<<endl;
        for(int i = 0; i < INF; i++){
            G[i].clear();

        }
    }
    return 0;
}