HDU ACM 2063 过山车(二分匹配)

http://acm.hdu.edu.cn/showproblem.php?pid=2063

 

#include <iostream>
#include <vector>
using namespace std;
const int MAX = 1500 + 10;
vector <int> v[MAX];
int link[MAX];
int used[MAX];
bool FindPath(int num)
{
    int len = v[num].size();
    int i;
    for(i=0;i<len;i++)
    {
        int n = v[num][i];
        if(!used[n])
        {
            used[n] = 1;
            if(link[n] == -1 || FindPath(link[n]))
            {
                link[n] = num;
                return true;
            }
        }
    }
    return false;
}
void Solve(int n)
{
    memset(link,-1,sizeof(link));
    int i;
    int num = 0;
    for(i=1;i<=n;i++)
    {
        memset(used,0,sizeof(used));
        if(FindPath(i))
        {
            num++;
        }
    }
    cout<<num<<endl;
}
int main()
{
    int k,f,m;
    while(cin>>k,k)
    {
        cin>>f>>m;
        int i;
        for(i=0;i<=f;i++)
        {
            v[i].clear();
        }
        for(i=0;i<k;i++)
        {
            int a,b;
            cin>>a>>b;
            v[a].push_back(b);
        }
        Solve(f);
    }
    return 0;
}