网络流初步——增广路算法（EK）模板

 #include <iostream>
 #include <queue>
 #include<string.h>
 using namespace std;
 #define arraysize 201
 int maxData = 0x7fffffff;
 int a[][];
 int flow[];
 int pre[];
 int n,m;
 queue<int> q;
 int BFS(int s,int t)
 {
     int i,j;
     while(!q.empty())
         q.pop();
     for(i=;i<m+;i++)
     {
         pre[i]=-;
     }
     pre[s]=;
     flow[s]= maxData;
     q.push(s);
     while(!q.empty())
     {
         int index=q.front();
         q.pop();
         if(index==t)
             break;
         for(i=;i<m+;++i)
         {
             if(i!=s && a[index][i]> && pre[i]==-)
             {
                  pre[i]=index;
                  flow[i]=min(a[index][i],flow[index]);
                  q.push(i);
             }
         }
     }
     if(pre[t]==-)
         return -;
     else
         return flow[t];
 }
 int ek(int s,int t)
 {
     int increasement=;
     int sumflow=;
     while((increasement=BFS(s,t))!=-)
     {
          int k=t;
          while(k!=s)
          {
               int last=pre[k];
               a[last][k]-=increasement;
               a[k][last]+=increasement;
               k = last;
          }
          sumflow+=increasement;
     }
     return sumflow;
 }
 int main()
 {
     int i,j;
     int start,end,ci;
     cin>>n>>m;
     memset(a,,sizeof(a));
     memset(flow,,sizeof(flow));
     for(i=;i<n;i++)
     {
         cin>>start>>end>>ci;
         a[start][end]+=ci;
     }
     cout<<ek(,m)<<endl;
     return ;
 }