/* shellsort: sort v[0]...v[n-1] into increasing order */ 
void 
shellsort (int v[], int n) 
{
  int gap, i, j, temp;
  for (gap = n/2; gap > 0; gap /= 2) 
    {
      for (i = gap; i < n; i++)
        {
          for (j=i-gap; j>=0 && v[j]>v[j+gap]; j-=gap) 
            {
              temp = v[j];
              v[j] = v[j+gap]; 
              v[j+gap] = temp;
            } // for (j)
         } // for (i)
     } // for (gap)
} // shellsort