[LeetCode]Binary Tree Postorder Traversal

题目描述:(链接)

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?

解题思路：

递归版：

 1 /**
 2  * Definition for a binary tree node.
 3  * struct TreeNode {
 4  *     int val;
 5  *     TreeNode *left;
 6  *     TreeNode *right;
 7  *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 8  * };
 9  */
10 class Solution {
11 public:
12     vector<int> postorderTraversal(TreeNode* root) {
13         if (root != nullptr) {
14             postorderTraversal(root->left);
15             postorderTraversal(root->right);
16             result.push_back(root->val);
17         }
18         
19         return result;
20     }
21 private:
22     vector<int> result;
23 };

迭代拌：待续

posted @ 2015-11-22 17:21  skycore  阅读(140)  评论(0)  编辑  收藏  举报