1 #include<cstdio> 2 #include<cstring> 3 #include<algorithm> 4 #include<queue> 5 using namespace std; 6 #define INF 2147483647 7 #define MAXN 20011 8 #define MAXM 600301 9 int v[MAXM],cap[MAXM],en,first[MAXN],next[MAXM];10 int d[MAXN],cur[MAXN],S,T;11 queue<int>q;12 int n,m;13 void Init_Dinic(){memset(first,-1,sizeof(first)); en=0;}14 void AddEdge(const int &U,const int &V,const int &W)15 {16     v[en]=V; cap[en]=W;17     next[en]=first[U];18     first[U]=en++;19     v[en]=V;20     next[en]=first[U];21     first[U]=en++;22 }23 bool bfs()24 {25     memset(d,-1,sizeof(d)); q.push(S); d[S]=0;26     while(!q.empty())27       {28           int U=q.front(); q.pop();29           for(int i=first[U];i!=-1;i=next[i])30             if(d[v[i]]==-1 && cap[i])31               {32                 d[v[i]]=d[U]+1;33                 q.push(v[i]);34               }35       }36     return d[T]!=-1;37 }38 int dfs(int U,int a)39 {40     if(U==T || !a) return a;41     int Flow=0,f;42     for(int &i=cur[U];i!=-1;i=next[i])43       if(d[U]+1==d[v[i]] && (f=dfs(v[i],min(a,cap[i]))))44         {45           cap[i]-=f; cap[i^1]+=f;46           Flow+=f; a-=f; if(!a) break;47         }48     if(!Flow) d[U]=-1;49     return Flow;50 }51 int max_flow()52 {53     int Flow=0,tmp=0;54     while(bfs())55       {56           memcpy(cur,first,(n+5)*sizeof(int));57           while(tmp=dfs(S,INF)) Flow+=tmp;58       }59     return Flow;60 }