【LEETCODE】226-Invert Binary Tree
Invert a binary tree.
4
/ \
2 7
/\ /\
1 3 6 9
to
4
/ \
7 2
/\ /\
9 6 3 1
4
/ \
2 7
/\ /\
1 3 6 9
to
4
/ \
7 2
/\ /\
9 6 3 1
# Definition for a binary tree node.
# class TreeNode(object):
# def __init__(self, x):
# self.val = x
# self.left = None
# self.right = None
class Solution(object):
def invertTree(self, root):
"""
:type root: TreeNode
:rtype: TreeNode
"""
if root == None: #root ，
return root
elif root.left == None and root.right == None: # root，
return root
else:
tmp = root.left # child
root.left = root.right
root.right = tmp
root.left = self.invertTree(root.left) # child
root.right = self.invertTree(root.right)
return root