技術標籤：algorithm二叉樹leetcode演算法

方法1：recursive

class Solution:
    def invertTree(self, root: TreeNode) -> TreeNode:
        if root is None:
            return None
        left = self.invertTree(root.left)
        right = self.invertTree(root.right)
        root.left = right
        root.right =
 
 left
        return root

方法2：iterative

思路和recursive類似，遇到一個node就把當前node的left和right翻轉

class Solution:
    def invertTree(self, root: TreeNode) -> TreeNode:
        if root is None:
            return None
        queue = [root]
        while queue:
            node = queue.pop()
            temp =
 
 node.left
            node.left = node.right
            node.right = temp
            if node.left:
                queue.append(node.left)
            if node.right:
                queue.append(node.right)
        return root