leetcode226 翻转二叉树——简单
# 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):
def dfs(root):
if root is None:
return
tmp=root.left
root.left=root.right
root.right=tmp
dfs(root.left)
dfs(root.right)
dfs(root)
return root
附加讨论区的另一种解法：
# 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):
if root is None:
return
root.left,root.right=root.right,root.left
self.invertTree(root.left)
self.invertTree(root.right)
return root