def __init__(self, data=None, leftChild=None, rightChild=None):
BinarySearchTree.__init__(self, data, leftChild, rightChild)
if (self.data != None):
self.height = 0
else:
self.height = -1
def __init__(self):
BinarySearchTree.__init__(self)
def __init__(self):
BinarySearchTree.__init__(self)
self.nil = self._new_node(None, None)
self.nil.right = self.nil.left = self.nil.parent = self.nil
self.r = self.nil
