def test_Delete(self):
tree = RBtree()
tree.insert(20)
tree.insert(15)
tree.insert(25)
tree.insert(23)
tree.insert(27)
self.assertFalse(tree.root.red, False)
self.assertEqual(tree.root.right.key, 25)
self.assertEqual(tree.root.right.left.key, 23)
self.assertTrue(tree.root.right.left.red, True)
tree.deleteNode(25)
self.assertEqual(tree.root.key, 20)
self.assertEqual(tree.root.right.key, 27)
self.assertFalse(tree.root.right.red, False)
self.assertIsNone(tree.root.right.right.key, None)
self.assertEqual(tree.root.right.left.key, 23)
self.assertTrue(tree.root.right.left.red, True)
def test_root_delete(self):
rb_tree = RBtree()
root = Node(5)
root.red = False
left_child = Node(3)
left_child.red = True
left_child.parent = root
left_child.left = Node(None)
left_child.right = Node(None)
right_child = Node(8)
right_child.red = True
right_child.parent = root
right_child.left = Node(None)
right_child.right = Node(None)
root.left = left_child
root.right = right_child
rb_tree.root = root
rb_tree.deleteNode(5)
self.assertEqual(rb_tree.root.key, 8)
self.assertEqual(rb_tree.root.left.key, 3)
