翻转二叉树【二叉树】

Problem: 226. 翻转二叉树

文章目录

• 思路 & 解题方法
• 复杂度
• Code

思路 & 解题方法

递归

复杂度

时间复杂度:

$O(n)$

空间复杂度:

$O(1)$

Code

# 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 invertTree(self, root: Optional[TreeNode]) -> Optional[TreeNode]:
        if not root:
            return
        root.left = self.invertTree(root.left)
        root.right = self.invertTree(root.right)
        t = root.left
        root.left = root.right
        root.right = t
        return root