最大流模板

#include <iostream>#include <queue>#include <cstring>using namespace std;const int N = 512;const int INF = 1000000;int cap[N][N];int mf(int s,int t);int mf(int s, int t){ int flow[N][N], lim[N], pre[N],f=0; queue<int>q; memset(flow,0,sizeof(flow)); while(true) { memset(lim,0,sizeof(lim)); lim[s]=INF; q.push(s); while(!q.empty()) { int u=q.front();q.pop(); for(int v=0;v<=t;v++) if(!lim[v] && cap[u][v]>flow[u][v]) { pre[v]=u;q.push(v); int dis = cap[u][v]-flow[u][v]; lim[v]=lim[u] < dis ? lim[u] : dis; } } if(lim[t]==0) break; for(int u=t;u!=s;u=pre[u]) { flow[pre[u]][u]+=lim[t]; flow[u][pre[u]]-=lim[t]; } f+=lim[t]; } return f;}