UVa 10591 Happy Number

UVa 10591 Happy Number

迭代得到Si的值，同时用set记录已经计算过的Si。如果出现1，成功；如果出现了已经出现过一次的值，失败（因为之后也不会再出现1）。
以下是我的代码：

#include < set >
#include < cstdio >
using   namespace  std;

int  f( int  x)
{
     int  re( 0 );
     while (x > 0 )
    {
         int  t(x % 10 );
        re += t * t;
        x /= 10 ;
    }
     return  re;
}

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

     int  T;
    scanf( " %d " , & T);
     for ( int  case_num = 1 ;case_num <= T;case_num ++ )
    {
         int  n;
        scanf( " %d " , & n);
        printf( " Case #%d: %d is  " ,case_num,n);

         set < int >  r;
         bool  success( false );
         while ( true )
        {
             if (n == 1 )
            {
                success = true ;
                 break ;
            }
             else   if (r.count(n) == 1 )
            {
                success = false ;
                 break ;
            }
            r.insert(n);
            n = f(n);
        }

         if (success)
            printf( " a Happy number.\n " );
         else
            printf( " an Unhappy number.\n " );
    }
}