Function Heap_remove_item

src/util/heap.c:296–326

remove item return item to be removed; NULL if item does not exist

// remove item
// return item to be removed; NULL if item does not exist
void *Heap_remove_item
(
	heap_t *hp,
	const void *item  // the item that is to be removed
) {
	int idx = __item_get_idx(hp, item);

	if(idx == -1) {
		return NULL;
	}

	// swap the item we found with the last item on the heap
	void *ret_item = hp->array[idx];
	hp->array[idx] = hp->array[hp->count - 1];
	hp->array[hp->count - 1] = NULL;

	hp->count -= 1;
	if(idx < hp->count) {
		if(hp->cmp(hp->array[idx], ret_item, hp->udata) < 0) {
			// replacement > removed
			// ensure heap property
			__pushdown(hp, idx);
		} else {
			// replacement <= removed
			// ensure heap property
			__pushup(hp, idx);
		}
	}

	return ret_item;
}

// test membership of item
// return 1 if the heap contains this item; otherwise 0