void
heap_increase_priority(heap_t *heap,
heap_item_t* item,
double new_priority,
double (*compute_priority)(heap_item_t*),
void (*set_priority)(heap_item_t*,double)) {
// assumes that priority and node mass are one and the same
double new_mass;
if (new_priority < compute_priority(item)) {
fprintf(stderr,"New priority is smaller than current priority.\n");
return;
}
new_mass = new_priority - item->node_mass;
set_priority(item,new_priority);
item->node_mass = new_priority;
item->subtree_mass += new_mass;
while (item->index > 0 && compute_priority(heap_parent(heap, item)) < compute_priority(item)) {
heap_parent(heap,item)->subtree_mass += new_mass;
heap_exchange(heap, item, heap_parent(heap, item));
item = heap_parent(heap, item);
}
while (item->index > 0) {
heap_parent(heap,item)->subtree_mass += new_mass;
item = heap_parent(heap, item);
}
}
static void
heap_heapify(struct heap_list *h, int i)
{
int l, r, largest;
void **p;
restart:
l = HEAP_LEFT(i);
r = HEAP_RIGHT(i);
p = h->heap_data;
if (l < h->heap_keys && (h->heap_comp_fun(p[l], p[i]) > 0))
largest = l;
else
largest = i;
if (r < h->heap_keys && h->heap_comp_fun(p[r], p[largest]) > 0)
largest = r;
if (largest != i) {
heap_exchange(h, i, largest);
i = largest;
goto restart;
}
}
