//最短增广路,Dinic算法 struct Edge { int from,to,cap,flow; };//弧度 void AddEdge(int from,int to,int cap) //增弧 { edges.push_back((Edge){from,to,cap,0}); edges.push_back((Edge){to,from,0,0}); m=edges.size(); G[from].push_back(m-2); G[to].push_back(m-1); } struct Dinic{ int n,m,s,t; vector<Edge> edges; vector<int> G[maxn]; bool vis[maxn]; int d[maxn]; int cur[maxn]; bool Bfs() //构建分层网络 { memset(vis,0,sizeof(vis)); queue<int> Q; Q.push(s); d[s]=0; vis[s]=1; while(!Q.empty()) { int x=Q.front(); Q.pop(); for(int i=0;i<G[x].size();i++) Edge& e=edges[G[x][i]]; if(!vis[e.to]&&e.cap>e.flow) { vis[e.to]=1; d[e.to]=d[x]+1; Q.push(e.to); } } return vis[t]; } }; int DFS(int x,int a)//沿阻塞流增广 { if(x==t||a==0) return a; int flow=0,f; for(int& i=cur[x];i<G[x].size();i++) { Edge& e=edges[G[x][i]]; if(d[x]+1==d[e.to]&&(f=DFS(e.to,min(a,e.cap-e.flow)))>0) { e.flow+=f; edges[G[x][i]^1].flow-=f; flow+=f; a-=f; if(a==0) break; } } return flow; } int Maxflow(int s,int t) { this->s=0; this->t=t; int flow=0; while(BFS()) { memset(cur,0,sizeof(cur)); flow+=DFS(s,inf); } return flow; }