二分图匹配——棋盘游戏 ( HDU 1281 )

#include <iostream>
#include <cstring>
#include <cstdio>
#include <queue>
#include <vector>
#include <algorithm>
#include <cmath>

using namespace std;

int Map[110][110];
int mark[110];
int flag[110];

int N,M,K;
int n;

bool DFS(int x)
{
for(int i=1;i<=M;i++)
{
if(!Map[x][i] || flag[i])
continue;
flag[i] = 1;
if(!mark[i] || DFS(mark[i]))
{
mark[i] = x;
return 1;
}
}
return 0;
}

int Hungarian()
{
int ans = 0;
memset(mark, 0, sizeof(mark));
for(int i=1;i<=N;i++)
{
memset(flag, 0, sizeof(flag));
if(DFS(i))
{
ans++;
}
}
return ans;
}

int main()
{
int t = 1;
while(cin >> N >> M >> K)
{
memset(Map,0,sizeof(Map));
n = max(N,M);
for(int i=0;i<K;i++)
{
int x,y;
cin >> x >> y;
Map[x][y] = 1;
}

int Ans = Hungarian();
int VIP = 0;

for(int i=1;i<=n;i++)
{
for(int j=1;j<=n;j++)
{
if(Map[i][j])
{
Map[i][j] = 0;
if(Hungarian() != Ans)
VIP++;
Map[i][j] = 1;
}
}
}
cout << "Board " << t++ <<" have " << VIP << " important blanks for " << Ans << " chessmen." << endl;
}
}