POJ 1273

#include < iostream >
#include < queue >
using   namespace  std;
struct  Map
{
     int  f,c;
}map[ 201 ][ 201 ];
int  pre[ 201 ],v[ 201 ];
queue < int > q;
int  n,m,a,b,c,s = 1 ;
int  main()
{
     while (cin >> n >> m)
    {
         int  i,j;
        memset(map, 0 , sizeof (map));
         while (n -- )
        {
            cin >> a >> b >> c;
            map[a][b].c += c;
        }
         while ( 1 )
        {
            memset(pre, 0 , sizeof (pre));
            v[s] = 0x7fffffff ;
            pre[s] = s;
             while ( ! q.empty())
                q.pop();
            q.push(s);
             while ( ! q.empty() && pre[m] == 0 )
            {
                i = q.front();
                q.pop();
                 for (j = 1 ;j <= m;j ++ )
                {
                     if (pre[j] == 0 )
                    {
                         if (map[i][j].f < map[i][j].c)
                        {
                            v[j] = min(v[i],map[i][j].c - map[i][j].f);
                            pre[j] = i;
                            q.push(j);
                        }
                         else   if (map[j][i].f > 0 )
                        {
                            v[j] = min(v[i],map[j][i].f);
                            pre[j] =- 1 * i;
                            q.push(j);
                        }
                    }
                }
            }
             if (pre[m] == 0 )
                 break ;
            i = m;
             while (i != s)
            {
                j = abs(pre[i]);
                 if (pre[i] > 0 )
                {
                    map[j][i].f += v[m];
                }
                 else
                {
                    map[i][j].f -= v[m];
                }
                i = j;
            }
        }
         int  ans = 0 ;
         for (i = 1 ;i <= m;i ++ )
        {
             if (i != s)
                ans += map[s][i].f;
        }
        cout << ans << endl;
    }
    system( " pause " );
     return   0 ;
}