学步园

#include <cstdio>
#include <cstring>
#include <iostream>
using namespace std;
const int M=510;
int m,n;
int map[M][M], match[M], chk[M];

int dfs(int p)
{
    int i;
    for(i=1;i<=m;i++)
        if( map[p][i] && chk[i]==0 )
        {
            chk[i]=1;
            if( match[i]==0 || dfs( match[i] ) )
            {
                match[i]=p;
                return 1;
            }
        }
    return 0;
}

int solve()
{
    int i,res;
    memset(match,0,sizeof(match));
    res=0;
    for(i=1; i<=n; i++)
    {
        memset(chk,0,sizeof(chk));
        res+=dfs(i);
    }
    return res;
}

int main()
{
    // freopen("in","r",stdin);
    // freopen("out","w",stdout);

    int k,i,r,x,y,ans,imp,ca=1;
    while(scanf("%d%d%d",&n,&m,&k)!=EOF)
    {
        memset(map,0,sizeof(map));
        
        for(i=0;i<k;i++)
        {
            scanf("%d%d",&x,&y);
            map[x][y]=1;
        }

        ans=solve(); imp=0;
        for(i=1;i<=n;i++)
        	for(r=1;r<=m;r++)
        		if(map[i][r])
        		{
        			map[i][r]=0;
        			if(solve()!=ans) imp++;
        			map[i][r]=1;
        		}
        printf("Board %d have %d important blanks for %d chessmen.\n",ca++, imp, ans);
    }
    return 0;
}