洛谷P3386 【模板】二分图匹配

匈牙利算法模板

 /*by SilverN*/
 #include<algorithm>
 #include<iostream>
 #include<cstring>
 #include<cstdio>
 #include<cmath>
 #include<vector>
 using namespace std;
 const int mxn=;
 int read(){
     int x=,f=;char ch=getchar();
     while(ch<'' || ch>''){if(ch=='-')f=-;ch=getchar();}
     while(ch>='' && ch<=''){x=x*+ch-'';ch=getchar();}
     return x*f;
 }
 int mp[mxn][mxn];
 int n,m,et;
 int link[mxn];
 bool vis[mxn];
 bool DFS(int u){
     for(int i=;i<=n;i++){
         if(!vis[i] && mp[u][i]){
             vis[i]=;
             if(link[i]==- || DFS(link[i])){
                 link[i]=u;
                 return ;
             }
         }
     }
     return ;
 }
 int solve(){
     int res=;
     for(int i=;i<=n;i++){
         memset(vis,,sizeof vis);
         if(DFS(i))res++;
     }
     return res;
 }
 int main(){
     n=read();m=read();et=read();
     int i,j;
     int u,v;
     for(i=;i<=et;i++){
         u=read();v=read();
         if(u>m || v>m)continue;
         mp[u][v]=mp[v][u]=;
     }
     memset(link,-,sizeof link);
     int ans=solve();
     printf("%d\n",ans);
     return ;
 }