UVa 167 The Sultan's Successors

UVa 167 The Sultan's Successors

八皇后问题，只不过每一个点上加了一个权值，求一个权值最大的解。
以下是我的代码：

#include < algorithm >
#include < cstdio >
#include < cstring >
using   namespace  std;

int  ans,r[ 8 ][ 8 ],d[ 8 ];
bool  used1[ 8 ],used2[ 20 ],used3[ 20 ];

void  dfs( int  depth)
{
     if (depth >= 8 )
    {
         int  t( 0 );
         for ( int  i = 0 ;i < 8 ;i ++ )
            t += r[i][d[i]];
        ans = max(ans,t);
         return ;
    }
     for ( int  i = 0 ;i < 8 ;i ++ )
         if ( ! used1[i]  &&   ! used2[depth + i]  &&   ! used3[ 8 + depth - i - 1 ])
        {
            d[depth] = i;
            used1[i] = used2[depth + i] = used3[ 8 + depth - i - 1 ] = true ;
            dfs(depth + 1 );
            used1[i] = used2[depth + i] = used3[ 8 + depth - i - 1 ] = false ;
        }
}

int  main()
{
    #ifndef ONLINE_JUDGE
    freopen( " data.in " , " r " ,stdin);
    freopen( " data.out " , " w " ,stdout);
     #endif

     int  T;
    scanf( " %d " , & T);
     while (T -- )
    {
         for ( int  i = 0 ;i < 8 ;i ++ )
             for ( int  j = 0 ;j < 8 ;j ++ )
                scanf( " %d " , & r[i][j]);

        ans = 0 ;
        memset(d, 0 , 8 * sizeof ( int ));
        memset(used1, false , 8 * sizeof ( bool ));
        memset(used2, false , 20 * sizeof ( bool ));
        memset(used3, false , 20 * sizeof ( bool ));
        dfs( 0 );

        printf( " %5d\n " ,ans);
    }

     return   0 ;
}