题目描述：
第一次提交：
class Solution(object): def invertTree(self, root): """ :type root: TreeNode :rtype: TreeNode """ if not root: return None temp = root.left root.left = root.right root.right = temp# root.left,root.right = root.right,root.left self.invertTree(root.left) self.invertTree(root.right) return root
可缩减代码：
class Solution(object): def invertTree(self, root): """ :type root: TreeNode :rtype: TreeNode """ if not root : return root else: root.left,root.right=self.invertTree(root.right),self.invertTree(root.left) return root