def test_adjacents(self):
root = RedBlackTreeNode(5, 5)
self.assertIsNone(root.predecessor)
self.assertIsNone(root.successor)
root.left = RedBlackTreeNode(2, 2)
root.right = RedBlackTreeNode(8, 8)
self.assertIs(root.predecessor, root.left)
self.assertIs(root.successor, root.right)
root.left.right = RedBlackTreeNode(3, 3)
root.right.left = RedBlackTreeNode(7, 7)
self.assertIs(root.predecessor, root.left.right)
self.assertIs(root.successor, root.right.left)
root.left.right.right = RedBlackTreeNode(4, 4)
root.right.left.left = RedBlackTreeNode(6, 6)
self.assertIs(root.predecessor, root.left.right.right)
self.assertIs(root.successor, root.right.left.left)
return
def test_black_height(self):
root = RedBlackTreeNode(5, 5)
left = RedBlackTreeNode(0, 0)
right = RedBlackTreeNode(10, 10)
root.red = left.red = right.red = False
root.left = left
root.right = right
left.parent = right.parent = root
self.assertEqual(root.black_height, 2)
left.red = right.red = True
self.assertEqual(root.black_height, 1)
right.red = False
try:
root.black_height
self.fail("Expected AssertionError")
except AssertionError:
pass
self.assertEquals(repr(root),
"RedBlackTreeNode(key=5, value=5, red=False)")
return
