We read every piece of feedback, and take your input very seriously.
To see all available qualifiers, see our documentation.
There was an error while loading. Please reload this page.
给定一个二叉树，返回它的 后序 遍历。
示例:
输入: [1,null,2,3] 1 \ 2 / 3 输出: [3,2,1]
进阶: 递归算法很简单，你可以通过迭代算法完成吗？
附赠leetcode地址：leetcode