//Shell Sort Function for Descending Order

void ShellSort( apvector <int> &num)
{
     int i, temp, flag = 1, numLength = num.length( );
     int d = numLength;
     while( flag || (d > 1))      // boolean flag (true when not equal to 0)
     {
          flag = 0;           // reset flag to 0 to check for future swaps
          d = (d+1) / 2;
          for (i = 0; i < (numLength - d); i++)
        {
               if (num[i + d] > num[i])
              {
                      temp = num[i + d];      // swap positions i+d and i
                      num[i + d] = num[i];
                      num[i] = temp;
                      flag = 1;                  // tells swap has occurred
              }
         }
     }
     return;
}