POJ 1966 Cable TV Network

POJ 1966 Cable TV Network

求无向图的连通度。
以下是我的代码：

#include < queue >
#include < algorithm >
#include < cstdio >
#include < cstring >
using   namespace  std;
const   int  kMaxn( 107 );
const   int  kInf( 0x7f7f7 );

int  n,m;
bool  g[kMaxn][kMaxn];
int  source,sink,maxflow,cap[kMaxn][kMaxn],flow[kMaxn][kMaxn];

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

    memset(flow, 0 ,kMaxn * kMaxn * sizeof ( int ));
    memset(d, 0x7f ,kMaxn * sizeof ( int ));
    memset(num, 0 ,kMaxn * sizeof ( int ));
    queue < int >  q;
    d[sink] = 0 ;
    num[ 0 ] ++ ;
    q.push(sink);
     while ( ! q.empty())
    {
         int  v(q.front());q.pop();
         for ( int  u = 1 ;u <= n;u ++ )
             if (d[u] >= n  &&  cap[u][v] > 0 )
            {
                d[u] = d[v] + 1 ;
                num[d[u]] ++ ;
                q.push(u);
            }
    }
    maxflow = 0 ;
     int  u(source),v;
     while (d[source] < n)
    {
        v =- 1 ;
         for ( int  i = 1 ;i <= n;i ++ )
             if (cap[u][i] > flow[u][i]  &&  d[u] == d[i] + 1 )
            {
                v = i; break ;
            }
         if (v !=- 1 )
        {
            p[v] = u;u = v;
             if (u == sink)
            {
                 int  add(kInf);
                 for (u = sink;u != source;u = p[u])
                    add = min(add,cap[p[u]][u] - flow[p[u]][u]);
                maxflow += add;
                 for (u = sink;u != source;u = p[u])
                {
                    flow[p[u]][u] += add;
                    flow[u][p[u]] -= add;
                }
            }
        }
         else
        {
            num[d[u]] -- ;
             if ( ! num[d[u]])
                 return ;
            d[u] = n;
             for (v = 1 ;v <= n;v ++ )
                 if (cap[u][v] > flow[u][v])
                    d[u] = min(d[u],d[v] + 1 );
            num[d[u]] ++ ;
             if (u != source)
                u = p[u];
        }
    }
}

int  VertexConnectivityDegree()
{
     int  re(kInf);
    memset(cap, 0 ,kMaxn * kMaxn * sizeof ( int ));
     for ( int  i = 1 ;i <= n;i ++ )
        cap[i][i + n] = 1 ;
     for ( int  i = 1 ;i <= n;i ++ )
         for ( int  j = 1 ;j <= n;j ++ )
             if (g[i][j])
                cap[i + n][j] = kInf;
     for ( int  i = 1 ;i <= n;i ++ )
         for ( int  j = 1 ;j <= n;j ++ )
             if (i != j  &&   ! g[i][j])
            {
                source = i + n;
                sink = j;
                n <<= 1 ;
                SAP();
                n >>= 1 ;
                re = min(re,maxflow);
            }
     if (re >= kInf)
        re = n - 1 ;
     return  re;
}

int  main()
{
     while (scanf( " %d%d " , & n, & m) == 2 )
    {
        memset(g, false ,kMaxn * kMaxn * sizeof ( bool ));
         for ( int  i = 1 ;i <= m;i ++ )
        {
             int  u,v;
            scanf( "  (%d,%d) " , & u, & v);
            u ++ ;v ++ ;
            g[u][v] = g[v][u] = true ;
        }

         int  ans(VertexConnectivityDegree());
         if (ans >= n - 1 )
            printf( " %d\n " ,n);
         else
            printf( " %d\n " ,ans);
    }

     return   0 ;
}