网络流-最大流 Dinic模板

 #include <bits/stdc++.h>

 using namespace std;

 #define MP make_pair
 #define PB push_back
 #define ls first
 #define rs second
 typedef long long LL;
 typedef pair<int,int> PII;
 const double eps=1e-;
 const double pi=acos(-1.0);
 const int K=1e5+;
 const int mod=1e9+;

 vector<pair<int,int>>mp[K];
 int n,m,cnt,flow[K*],deep[K],cur[K];  

 int bfs(int s,int t)
 {
     queue<int>q;
     memset(deep,,sizeof deep);
     q.push(s),deep[s]=;
     while(!q.empty())
     {
         int u=q.front();q.pop();
         for(auto &it:mp[u])
         if(!deep[it.ls]&&flow[it.rs])
         {
             deep[it.ls]=deep[u]+;
             q.push(it.ls);
             if(it.ls==t)
                 return ;
         }
     }
     return ;
 }
 int dfs(int x,int d,int t)
 {
     if(x==t) return d;
     for(int i=cur[x];i<mp[x].size();cur[x]=++i)
     {
         int u=mp[x][i].ls,v=mp[x][i].rs;
         if(deep[u]==deep[x]+&&flow[v])
         {
             int td=min(d,dfs(u,min(d,flow[v]),t));
             if(!td) continue;
             flow[v]-=td;
             flow[v^]+=td;
             return td;
         }
     }
     return ;
 }
 int dinic(int s,int t)
 {
     int ret=,d;
     while(bfs(s,t))
     {
         memset(cur,,sizeof cur);
         while(d=dfs(s,mod,t))    ret+=d;
     }
     return ret;
 }
 int main(void)
 {
     while(~scanf("%d%d",&m,&n))
     {
         cnt=;
         memset(mp,,sizeof mp);
         for(int i=,u,v,w;i<m;i++)
         {
             scanf("%d%d%d",&u,&v,&w);
             flow[cnt]=w,flow[cnt+]=;
             mp[u].PB(MP(v,cnt++));
             mp[v].PB(MP(u,cnt++));
         }
         printf("%d\n",dinic(,n));
     }
     return ;
 }