Function heapify_down

gl/lib/heap.c:110–132

/* Move element down into appropriate position in heap. */

static void
heapify_down (void **array, idx_t count, idx_t initial,
              int (*compare) (void const *, void const *))
{
  void *element = array[initial];

  idx_t parent = initial;
  while (parent <= count >> 1)
    {
      idx_t child = 2 * parent;

      if (child < count && compare (array[child], array[child + 1]) < 0)
        child++;

      if (compare (array[child], element) <= 0)
        break;

      array[parent] = array[child];
      parent = child;
    }

  array[parent] = element;
}

/* Move element up into appropriate position in heap. */