翻转二叉树 leetcode226
翻转一棵二叉树。
输入:
4
/ \
2 7
/ \ / \
1 3 6 9
输出:
4
/ \
7 2
/ \ / \
9 6 3 1
代码如下:
# Definition for a binary tree node.
class TreeNode:
def __init__(self, x):
self.val = x
self.left = None
self.right = None
class Solution:
def invertTree(self, root: TreeNode) -> TreeNode:
if not root:
return
root.left, root.right = root.right, root.left
self.invertTree(root.left)
self.invertTree(root.right)