LeetCode-Binary Tree Postorder Traversal

作者：disappearedgod

文章出处：http://blog.csdn.net/disappearedgod/article/details/28440827

时间：2014-6-3

题目

Binary Tree Postorder Traversal

 Total Accepted: 17952 Total Submissions: 58422My Submissions

Given a binary tree, return the postorder traversal of its nodes' values.

For example:
Given binary tree {1,#,2,3},

   1    \     2    /   3

return [3,2,1].

Note: Recursive solution is trivial, could you do it iteratively?

解法

public ArrayList<Integer> postorderTraversal(TreeNode root) {        ArrayList<Integer> retlist = new ArrayList<Integer>();        return postorderTraversal(root,retlist);    }    public ArrayList<Integer> postorderTraversal(TreeNode root, ArrayList<Integer> retlist) {        if(root == null)            return retlist;        postorderTraversal(root.left,retlist);        postorderTraversal(root.right,retlist);        ArrayList<Integer> addlist = new ArrayList<Integer>();        addlist.add(root.val);        retlist.addAll(addlist);                return retlist;    }

返回

LeetCode Solution(持续更新，java>c++)