POJ 1459 Power Network

POJ 1459 Power Network

多源点汇点的网络流最大流问题。
注意题目要求顶点编号从0开始。我是用SAP算法来做的，用时766ms；EdmondsKarp算法用时1610ms。
以下是我的代码：

#include < iostream >
#include < sstream >
#include < string >
#include < queue >
#include < algorithm >
#include < cstdio >
#include < cstring >
#include < cctype >
using   namespace  std;
const   int  kMaxn( 107 );
const   int  kInf( 0x7f7f7f7f );

int  n,np,nc,m,s,t,c[kMaxn][kMaxn];
int  maxflow,f[kMaxn][kMaxn];

void  SAP()
{
     int  d[kMaxn],num[kMaxn],p[kMaxn];

    memset(f, 0 ,kMaxn * kMaxn * sizeof ( int ));
    memset(d, 0x7f ,kMaxn * sizeof ( int ));
    memset(num, 0 ,kMaxn * sizeof ( int ));
    queue < int >  q;
    d[t] = 0 ;
    num[ 0 ] ++ ;
    q.push(t);
     while ( ! q.empty())
    {
         int  v(q.front());q.pop();
         for ( int  u = 0 ;u < n;u ++ )
             if (d[u] >= n  &&  c[u][v] > f[u][v])
            {
                d[u] = d[v] + 1 ;
                num[d[u]] ++ ;
                q.push(u);
            }
    }

    maxflow = 0 ;
     int  u(s),v;
     while (d[s] < n)
    {
        v =- 1 ;
         for ( int  i = 0 ;i < n;i ++ )
             if (c[u][i] > f[u][i]  &&  d[u] == d[i] + 1 )
            {v = i; break ;}
         if (v !=- 1 )
        {
            p[v] = u;u = v;
             if (u == t)
            {
                 int  add(kInf);
                 for (u = t;u != s;u = p[u])
                    add = min(add,c[p[u]][u] - f[p[u]][u]);
                maxflow += add;
                 for (u = t;u != s;u = p[u])
                {
                    f[p[u]][u] += add;
                    f[u][p[u]] -= add;
                }
            }
        }
         else
        {
            num[d[u]] -- ;
             if ( ! num[d[u]])
                 return ;
            d[u] = n;
             for (v = 0 ;v < n;v ++ )
                 if (c[u][v] > f[u][v])
                    d[u] = min(d[u],d[v] + 1 );
            num[d[u]] ++ ;
             if (u != s)
                u = p[u];
        }
    }
}

int  main()
{
     while (scanf( " %d%d%d%d " , & n, & np, & nc, & m) == 4 )
    {
        s = n;
        t = n + 1 ;
        n += 2 ;
        memset(c, 0 ,kMaxn * kMaxn * sizeof ( int ));
         for ( int  i = 1 ;i <= m;i ++ )
        {
             string   in ;
            cin >> in ;
             for ( int  j = 0 ;j < in .size();j ++ )
                 if ( ! isdigit( in [j]))
                     in [j] = '   ' ;
            istringstream sin( in );
             int  u,v,w;
            sin >> u >> v >> w;
            c[u][v] += w;
        }
         for ( int  i = 1 ;i <= np;i ++ )
        {
             string   in ;
            cin >> in ;
             for ( int  j = 0 ;j < in .size();j ++ )
                 if ( ! isdigit( in [j]))
                     in [j] = '   ' ;
            istringstream sin( in );
             int  u,v;
            sin >> u >> v;
            c[s][u] += v;
        }
         for ( int  i = 1 ;i <= nc;i ++ )
        {
             string   in ;
            cin >> in ;
             for ( int  j = 0 ;j < in .size();j ++ )
                 if ( ! isdigit( in [j]))
                     in [j] = '   ' ;
            istringstream sin( in );
             int  u,v;
            sin >> u >> v;
            c[u][t] += v;
        }

        SAP();

        printf( " %d\n " ,maxflow);
    }

     return   0 ;
}