翻转二叉树

LeetCode题目地址

def invertBinaryTree(self, root):
        # 递归
        self.dfs(root)
    def dfs(self, node):
        if node == None:
            return
        left = node.left
        right = node.right
        node.left = right
        node.right = left
        self.dfs(left)
        self.dfs(right)