网络流最大流模板

```cpp int fir[N],sz=1,to[N],flow[N],dl[N],deep[N], n,m; void add1(int x,int y,int z){ nxt[++sz]=fir[x];to[sz]=y; fir[x]=sz;flow[sz]=z; } void add(int x,int y,int z){ add1(x,y,z),add1(y,x,0); } bool bfs(int S,int T){ memset(deep,0,(tot+2)<<2); deep[S]=1;dl[1]=S;int head=0,tail=1; while(head!=tail){ int v=dl[++head]; for(int u=fir[v];u;u=nxt[u]){ if(flow[u]&&!deep[to[u]]){ deep[to[u]]=deep[v]+1; dl[++tail]=to[u]; } } } return deep[T]; } int aim; int dfs(int now,int fl){ if(now==aim)return fl; int f=0; for(int u=fir[now];u&&fl;u=nxt[u]){ if(flow[u]&&deep[to[u]]==deep[now]+1){ int x=dfs(to[u],min(fl,flow[u])); flow[u]-=x;flow[u^1]+=x;fl-=x;f+=x; } } if(!f)deep[now]=-2; return f; } int maxflow(int S,int T){ aim=T;int ret=0; while(bfs(S,T)){ ret+=dfs(S,1<<30); } return ret; } ```