匈牙利算法 最大匹配 模板

#include <bits/stdc++.h>
using namespace std;
const int MAXN = 1005;
int n, m, e;

int match[MAXN];
bool g[MAXN][MAXN], vis[MAXN];

bool dfs(int u)
{
    for(int v = 1; v <= m; v++)
        if(g[u][v] && !vis[v])
        {
            vis[v] = 1;
            if(match[v] == -1 || dfs(match[v]))
            {
                match[v] = u; return 1;
            }
        }
    return 0;
}

inline int Maxmatch()
{
    memset(match, -1, sizeof match);
    int ret = 0;
    for(int i = 1; i <= n; i++)
    {
        memset(vis, 0, sizeof vis);
        ret += dfs(i);
    }
    return ret;
}

int main()
{
    int x, y;
    scanf("%d%d%d", &n, &m, &e);
    while(e--)
    {
        scanf("%d%d", &x, &y);
        if(x <= n && y <= m) g[x][y] = 1;
    }
    printf("%d
", Maxmatch());
}

O(n^3)