Leetcode 226. Invert Binary Tree
题目描述:倒置二叉树、左子树与右子树交换。
题目链接:Leetcode 226. Invert Binary Tree
题目思路:利用二叉树的层序遍历,不断交换左右子树,直到最后一层节点。
代码如下
class Solution:
def invertTree(self, root):
"""
:type root: TreeNode
:rtype: TreeNode
"""
if not root:
return None
nodes=[root]
while(nodes):
curr = nodes.pop(0)
curr.left,curr.right = curr.right,curr.left
if curr.left:
nodes.append(curr.left)
if curr.right:
nodes.append(curr.right)
return root