def test_insert_a_second_node_to_right(self):
rbt = RedBlackTree()
rbt.rbt_insert(RedBlackTree.Node(20))
rbt.rbt_insert(RedBlackTree.Node(30))
assert rbt.root.key == 20
assert rbt.root.is_black()
assert rbt.root.right.key == 30
assert rbt.root.right.is_red()
def test_insert_a_second_node_to_left(self):
rbt = RedBlackTree()
rbt.rbt_insert(RedBlackTree.Node(20))
rbt.rbt_insert(RedBlackTree.Node(10))
assert rbt.root.key == 20
assert rbt.root.is_black()
assert rbt.root.left.key == 10
assert rbt.root.left.is_red()
def test_force_double_rotate_left_then_right(self):
rbt = RedBlackTree()
rbt.rbt_insert(RedBlackTree.Node(20))
rbt.rbt_insert(RedBlackTree.Node(10))
rbt.rbt_insert(RedBlackTree.Node(15))
assert rbt.root.key == 15
assert rbt.root.is_black()
assert rbt.root.left.key == 10
assert rbt.root.left.is_red()
assert rbt.root.right.key == 20
assert rbt.root.right.is_red()
def test_force_left_rotate(self):
rbt = RedBlackTree()
rbt.rbt_insert(RedBlackTree.Node(20))
rbt.rbt_insert(RedBlackTree.Node(30))
rbt.rbt_insert(RedBlackTree.Node(40))
assert rbt.root.key == 30
assert rbt.root.is_black()
assert rbt.root.left.key == 20
assert rbt.root.left.is_red()
assert rbt.root.right.key == 40
assert rbt.root.right.is_red()
def test_force_right_rotate(self):
rbt = RedBlackTree()
rbt.rbt_insert(RedBlackTree.Node(20))
rbt.rbt_insert(RedBlackTree.Node(10))
rbt.rbt_insert(RedBlackTree.Node(5))
assert rbt.root.key == 10
assert rbt.root.is_black()
assert rbt.root.left.key == 5
assert rbt.root.left.is_red()
assert rbt.root.right.key == 20
assert rbt.root.right.is_red()
def test_insert_nodes_to_left_and_right(self):
rbt = RedBlackTree()
rbt.rbt_insert(RedBlackTree.Node(20))
rbt.rbt_insert(RedBlackTree.Node(10))
rbt.rbt_insert(RedBlackTree.Node(30))
assert rbt.root.key == 20
assert rbt.root.is_black()
assert rbt.root.left.key == 10
assert rbt.root.left.is_red()
assert rbt.root.right.key == 30
assert rbt.root.right.is_red()
def four_node_factory(self):
rbt = RedBlackTree()
rbt.rbt_insert(RedBlackTree.Node(30))
rbt.rbt_insert(RedBlackTree.Node(40))
rbt.rbt_insert(RedBlackTree.Node(20))
rbt.rbt_insert(RedBlackTree.Node(10))
assert rbt.root.key == 30
assert rbt.root.is_black()
assert rbt.root.left.key == 20
assert rbt.root.left.is_black()
assert rbt.root.right.key == 40
assert rbt.root.right.is_black()
assert rbt.root.left.left.key == 10
assert rbt.root.left.left.is_red()
return rbt
def test_right_left_case(self):
rbt = RedBlackTree()
rbt.rbt_insert(RedBlackTree.Node(30))
rbt.rbt_insert(RedBlackTree.Node(20))
rbt.rbt_insert(RedBlackTree.Node(40))
rbt.rbt_insert(RedBlackTree.Node(35))
assert rbt.root.key == 30
assert rbt.root.is_black()
assert rbt.root.left.key == 20
assert rbt.root.left.is_black()
assert rbt.root.right.key == 40
assert rbt.root.right.is_black()
assert rbt.root.right.left.key == 35
assert rbt.root.right.left.is_red()
rbt.rbt_delete(rbt.root.left)
assert rbt.root.key == 35
# assert rbt.root.is_black()
assert rbt.root.left.key == 30
# assert rbt.root.left.is_black()
assert rbt.root.right.key == 40
def test_insert_root_into_red_black_tree(self):
rbt = RedBlackTree()
rbt.rbt_insert(RedBlackTree.Node(20))
assert rbt.root.key == 20
assert rbt.root.is_black()
