def test_delete_last():
heap = Heap()
items = [KeyedItem(key=i) for i in range(10)]
heap.heapify(items)
heap.delete(items[9])
for i in range(9):
assert heap.extract_root() is items[i]
assert heap.extract_root() is None
def test_delete_root():
heap = Heap()
items = [KeyedItem(key=i) for i in range(10)]
random_items = [item for item in items]
random.shuffle(random_items)
heap.heapify(random_items)
heap.delete(items[0])
for i in range(1, 10):
assert heap.extract_root() is items[i]
assert heap.extract_root() is None
def test_delete_with_bubble_down():
heap = Heap()
items_keys = list(range(5)) + list(range(100, 112))
items = [KeyedItem(key=i) for i in items_keys]
heap.heapify(items)
heap.delete(items[5])
for i in range(17):
if i != 5:
root = heap.extract_root()
assert root is items[i]
assert heap.extract_root() is None
def test_delete_with_bubble_up():
heap = Heap()
items_keys = (list(range(2)) + [100] + list(range(2, 4)) +
list(range(101, 103)) + list(range(4, 8)) +
list(range(103, 107)) + list(range(8, 10)))
items = [KeyedItem(key=i) for i in items_keys]
heap.heapify(items)
heap.delete(items[5])
for i in range(2):
assert heap.extract_root() is items[i]
for i in range(3, 5):
assert heap.extract_root() is items[i]
for i in range(7, 11):
assert heap.extract_root() is items[i]
for i in range(15, 17):
assert heap.extract_root() is items[i]
assert heap.extract_root() is items[2]
assert heap.extract_root() is items[6]
for i in range(11, 15):
assert heap.extract_root() is items[i]
assert heap.extract_root() is None
def test_delete_only_item():
heap = Heap()
item = KeyedItem(key=0)
heap.insert(item)
heap.delete(item)
assert heap.extract_root() is None