稀疏图慢死了。。。但是稠密图效果还是很好的
1 struct MCMF{ 2 struct tedge{int x,y,cap,w,next;}adj[maxm];int ms,fch[maxn]; 3 int vis[maxn],d[maxn],ans,cost,S,T,n; 4 void init(int n){ 5 this->n=n;ms=0;ans=cost=0; 6 memset(fch,-1,sizeof(fch)); 7 return; 8 } 9 inline void addedge(int u,int v,int cap,int w){ 10 adj[ms]=(tedge){u,v,cap,w,fch[u]};fch[u]=ms++; 11 adj[ms]=(tedge){v,u,0,-w,fch[v]};fch[v]=ms++; 12 return; 13 } 14 inline int aug(int u,int f){ 15 if(u==T){ans+=cost*f;return f;} 16 int tmp=f;vis[u]=1; 17 for(int i=fch[u];i!=-1;i=adj[i].next){ 18 int v=adj[i].y; 19 if(adj[i].cap&&!adj[i].w&&!vis[v]){ 20 int a=aug(v,tmp<adj[i].cap?tmp:adj[i].cap); 21 adj[i].cap-=a; 22 adj[i^1].cap+=a; 23 tmp-=a; 24 if(!tmp) return f; 25 } 26 } return f-tmp; 27 } 28 inline bool spfa(){ 29 for(int i=1;i<=n;i++) d[i]=inf; 30 deque<int>Q;Q.push_back(T);d[T]=0; 31 while(!Q.empty()){ 32 int u=Q.front(),tmp;Q.pop_front(); 33 for(int i=fch[u];i!=-1;i=adj[i].next) 34 if(adj[i^1].cap&&(tmp=d[u]-adj[i].w)<d[adj[i].y]) 35 (d[adj[i].y]=tmp)<=d[Q.empty()?S:Q.front()]?Q.push_front(adj[i].y):Q.push_back(adj[i].y); 36 } 37 for(int u=1;u<=n;u++) 38 for(int i=fch[u];i!=-1;i=adj[i].next) 39 adj[i].w+=d[adj[i].y]-d[u]; 40 cost+=d[S];return d[S]<inf; 41 } 42 int costflow(int S,int T){ 43 this->S=S;this->T=T; 44 while(spfa())do memset(vis,false,sizeof(vis));while(aug(S,inf)); 45 return ans; 46 } 47 }sol;