hdu1068 Girls and Boys (二分图最大独立集)

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=1068

#include <stdio.h>
#include <string.h>
#define MAXN 1002

int map[MAXN][MAXN];
int from[MAXN],used[MAXN];
//二分图最大独立集 = 顶点数 -  二分图最大匹配
int match(int x,int n)//匈牙利算法
{
int i;
for(i=0;i<n;++i)//被匹配的男生
{
if(!used[i]&&map[x][i])
{
used[i]=1;
if(from[i]==-1||match(from[i],n))
{
from[i]=x; //男生[i]属于女生x
return 1;
}
}
}
return 0;
}

int main()
{
int k,n,m,sum,i,j;
while(scanf("%d",&n)!=EOF)
{
memset(map,0,sizeof(map));
memset(from,-1,sizeof(from));
sum=0;
for(k=0;k<n;++k)
{
scanf("%d: (%d)",&i,&m);
while(m--)
{
scanf("%d",&j);
map[i][j]=1;
}
}
for(i=0;i<n;++i)//女生去匹配男生
{
memset(used,0,sizeof(used));
if(match(i,n))
++sum;
}
printf("%d\n",n-sum/2);
}
return 0;
}

#include <cstdio>
#include <cstring>
#include <vector>
#define MAXN 1001
using namespace std;

vector<int> mp[MAXN];
int from[MAXN],used[MAXN],n;

int find(int x)
{
int temp,size;
size=mp[x].size();
for(int i=0;i<size;++i)
{
temp=mp[x][i];
if(!used[temp])
{
used[temp]=1;
if(from[temp]==-1||find(from[temp]))
{
from[temp]=x;
return 1;
}
}
}
return 0;
}

int main()
{
int k,n,m,sum,i,j;
while(scanf("%d",&n)!=EOF)
{
for(i=0;i<=n;++i)
mp[i].clear();
memset(from,-1,sizeof(from));
sum=0;
for(k=0;k<n;++k)
{
scanf("%d: (%d)",&i,&m);
while(m--)
{
scanf("%d",&j);
mp[i].push_back(j);
}
}
for(i=0;i<n;++i)//女生去匹配男生
{
memset(used,0,sizeof(used));
if(find(i))
++sum;
}
printf("%d\n",n-sum/2);
}
return 0;
}