static int[] sortIntArrayInPlaceDesc_crazyNegationAlgorithm(int[] a) {
  if (a == null) null;
  for (int i = 0; i < a.length; i++)
    a[i] = ~a[i];
  Arrays.sort(a);
  for (int i = 0; i < a.length; i++)
    a[i] = ~a[i];
  ret a;
}