def test_delete_with_linked_list_trees(self):
# Create a complete binary search tree of 7 items in level-order
items = [1, 2, 3, 4, 5, 6]
tree = BinarySearchTree(items)
tree.delete(2)
assert tree.root.data == 1
assert tree.root.left is None
assert tree.root.right.data == 3
assert tree.root.right.right.data == 4
assert tree.root.right.left is None
def test_delete_with_unbalanced_trees(self):
# Create a complete binary search tree of 7 items in level-order
items = [3, 6, 1, 2, 5, 7]
tree = BinarySearchTree(items)
tree.delete(2)
assert tree.root.data == 3
assert tree.root.left.data == 1
assert tree.root.right.data == 6
assert tree.root.left.left is None
assert tree.root.left.right is None
def test_deletion_leaf(self):
bt = BinarySearchTree()
bt.insert_multiple_values([10, 20, 22, 3, 7, 4, 32, 900])
node, depth = bt.search(900)
self.assertEqual(node.value, 900)
self.assertEqual(depth, 4)
bt.delete(900)
node, _ = bt.search(900)
self.assertIsNone(node)
self.assertEqual(bt.in_order(), [3, 4, 7, 10, 20, 22, 32])
def test_deletion_first_use_case(self):
bt = BinarySearchTree()
bt.insert_multiple_values([10, 20, 22, 3, 7, 4, 32, 900])
node, depth = bt.search(4)
self.assertEqual(node.value, 4)
self.assertEqual(depth, 3)
bt.delete(4)
node, depth = bt.search(4)
self.assertIsNone(node)
self.assertEqual(bt.in_order(), [3, 7, 10, 20, 22, 32, 900])
def test_delete_with_3_items(self):
# Create a complete binary search tree of 3 items in level-order
items = [2, 1, 3]
tree = BinarySearchTree(items)
assert tree.root.data == 2
assert tree.root.left.data == 1
assert tree.root.right.data == 3
tree.delete(2)
assert tree.root.data == 1
assert tree.root.left is None
assert tree.root.right.data is 3
tree.delete(1)
assert tree.root.data == 3
assert tree.root.left is None
assert tree.root.right is None
tree.delete(3)
assert tree.root is None
def test_delete_with_7_items(self):
# Create a complete binary search tree of 7 items in level-order
items = [4, 2, 6, 1, 3, 5, 7]
tree = BinarySearchTree(items)
tree.delete(4)
assert tree.root.data == 3
assert tree.root.left.data == 2
assert tree.root.right.data == 6
assert tree.root.left.left.data == 1
assert tree.root.left.right is None
tree.delete(6)
assert tree.root.data == 3
assert tree.root.left.data == 2
assert tree.root.right.data == 5
assert tree.root.right.left is None
assert tree.root.right.right.data == 7
tree.delete(5)
assert tree.root.data == 3
assert tree.root.left.data == 2
assert tree.root.right.data == 7
assert tree.root.right.left == None
assert tree.root.right.right == None