def delete(self, num: int, node: TreeNode = None):
node = node or self.root
if num < node.val:
node.left = self.delete(num, node.left)
elif num > node.val:
node.right = self.delete(num, node.right)
else:
self.size -= 1
if node.left is None and node.right is None:
if self.root == node:
self.root = None
return None
elif node.left is None:
if self.root == node:
self.root = node.right
return node.right
elif node.right is None:
if self.root == node:
self.root = node.left
return node.left
else:
min_node = node.right
while min_node.left:
min_node = min_node.left
node.val = min_node.val
node.right = self.delete(min_node.val, node.right)
return node
def delete(self, node: TreeNode, val: int):
if node is None:
return
if val < node.val:
node.left = self.delete(node.left, val)
if val > node.val:
node.right = self.delete(node.right, val)
if val == node.val:
if node.left and node.right:
predecessor = node.left
while predecessor.right:
predecessor = predecessor.right
node.val = predecessor.val
predecessor.val = val
node.left = self.delete(node.left, val)
elif node.left:
return node.left
elif node.right:
return node.right
else:
return None
return node