class Node(object): def __init__(self, data): self.data = data self.left = None self.right = None self.parent = None def __str__(self): return str(self.data) def insert(root, data): # Constraint: Assume we are working with valid ints if root is None: root = Node(data) return root if data <= root.data: if root.left is None: root.left = insert(root.left, data) root.left.parent = root return root.left else: return insert(root.left, data) else: if root.right is None: root.right = insert(root.right, data) root.right.parent = root return root.right else: return insert(root.right, data)