【hot100篇-python刷题记录】【翻转二叉树】
R7-二叉树篇
一眼递归
递归具有相同子问题的特点。
# 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 root is None:
return None
left=self.invertTree(root.left)
right=self.invertTree(root.right)
root.left=right
root.right=left
return root 
ps:
今天很顺利地拿下