leetcode#226 Invert Binary Tree

1. 문제

• https://leetcode.com/problems/invert-binary-tree/
  
  

2. 나의 풀이

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution:
    def foo(self, node):
        if node and (node.left or node.right):
            node.left, node.right = node.right, node.left
            self.foo(node.left)
            self.foo(node.right)
        return
    
    def invertTree(self, root: Optional[TreeNode]) -> Optional[TreeNode]:
        self.foo(root)
        return root

Reference