static void
heap_fix_top_down (struct heap *heap, unsigned pos)
{
for (;;)
{
if (heap_get_left_child (pos) >= heap->elem_cnt)
break;
if (heap_less (heap, heap_get_left_child (pos), pos))
{
heap_swap (heap, heap_get_left_child (pos), pos);
pos = heap_get_left_child (pos);
continue;
}
if (heap_get_right_child (pos) >= heap->elem_cnt)
break;
if (heap_less (heap, heap_get_right_child (pos), pos))
{
heap_swap (heap, heap_get_left_child (pos), pos);
pos = heap_get_left_child (pos);
continue;
}
break;
}
}
static void heap_siftup(heap_t *h, int k) {
for ( ; ; ) {
int l, r, s;
l = k * 2 + 1; /* left child */
r = k * 2 + 2; /* right child */
/* find the smallest of the three */
s = k;
if (l < h->len && heap_less(h, l, s)) s = l;
if (r < h->len && heap_less(h, r, s)) s = r;
if (s == k) {
return; /* statisfies the heap property */
}
heap_swap(h, k, s);
k = s;
}
}
static void heap_siftdown(heap_t *h, int k) {
for ( ; ; ) {
int p = (k - 1) / 2; /* parent */
if (k == 0 || heap_less(h, p, k)) {
return;
}
heap_swap(h, k, p);
k = p;
}
}
static void
heap_fix_bottom_up (struct heap *heap, unsigned pos)
{
while (!heap_is_root (pos))
{
if (!heap_less (heap, pos, heap_get_parent (pos)))
break;
heap_swap (heap, pos, heap_get_parent (pos));
pos = heap_get_parent (pos);
}
}