pqdownheap
pqdownheap(s, tree, SMALLEST); \
for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
pqdownheap(s, tree, SMALLEST);
pqdownheap(s, tree, SMALLEST); \
for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
pqdownheap(s, tree, SMALLEST);