void bubbleSort(int a[], int lo, int hi)
{
   int i, j, nswaps;
   for (i = lo; i < hi; i++) {
      nswaps = 0;
      for (j = hi; j > i; j--) {
         if (less(a[j], a[j-1])) {
            swap(a[j], a[j-1]);  nswaps++;
         }
      }
      if (nswaps == 0) break;
   }
}


(a)
lo       hi
5 1 2 6 4 3  start i == 0
5 1 2 6 3 4
5 1 2 3 6 4
1 5 2 3 6 4  start i == 1
1 5 2 3 4 6
1 2 5 3 4 6
1 2 3 5 4 6
1 2 3 4 5 6



(b)
lo       hi
1 2 3 4 5 6


(c)
lo       hi
6 5 4 3 2 1