最大二分匹配

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
  
int n,m,l;
int linker[505];  
bool used[505];  
int g[505][505];

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

int MaxMatch()
{  
    int ans = 0;  
    memset(linker,-1,sizeof(linker));  
    for(int i = 0;i < n;i++)
    {  
        memset(used,0,sizeof(used));
        if(dfs(i))    ans++;
    }
    return ans;
}  
   
int main()
{  
    int a,b;  
    while(~scanf("%d%d",&n,&m))
    {   
        memset(g,0,sizeof(g));
        scanf("%d",&l);
        for(int i = 0;i < l;i++)
        {  
            scanf("%d%d",&a,&b);  
            g[a][b] = 1;
        }  
        printf("%d\n",MaxMatch());
    }  
    return 0;     
} 

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<vector> 
using namespace std;
  
int n,m,l;
int linker[505];  
bool used[505];  
vector<int> v[505];

bool dfs(int u)
{
    for(int i = 0;i < v[u].size();i++)
    {
        int t = v[u][i];
        if(!used[t])
        {
            used[t] = 1;
            if(linker[t] == -1 || dfs(linker[t]))
            {
                linker[t] = u;
                return 1;
            }  
        }  
    }
    return 0;  
}  

int MaxMatch()
{  
    int ans = 0;  
    memset(linker,-1,sizeof(linker));  
    for(int i = 0;i < n;i++)
    {  
        memset(used,0,sizeof(used));
        if(dfs(i))    ans++;
    }
    return ans;
}  
   
int main()
{  
    int a,b;  
    while(~scanf("%d%d",&n,&m))
    {   
        for(int i = 0;i < n;i++)    v[i].clear();
        scanf("%d",&l);
        for(int i = 0;i < l;i++)
        {  
            scanf("%d%d",&a,&b);  
            v[a].push_back(b);
        }  
        printf("%d\n",MaxMatch());
    }  
    return 0;     
}