LeetCode Binary Tree Inorder Traversal

Description

Given a binary tree, return the inorder traversal of its nodes’ values.

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

2
/
3
return [1,3,2].

The original problem is here.

The original code is here.

My Solution

I solve this problem in C++, as below:

/*
*Binary Tree Inorder Traversal  
*Author: shuaijiang
*Email: zhaoshuaijiang8@gmail.com
*/
#include<iostream>
#include<stack>
#include<stdlib.h>
using namespace std;

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {
public:
    vector<int> inorderTraversal(TreeNode* root) {
        stack<TreeNode*> myStack;
        vector<int> result;
        if(root == NULL)
            return result;
        myStack.push(root);
        while(!myStack.empty()){
            TreeNode * node = myStack.top();
            myStack.pop();
            if(node->left == NULL && node->right == NULL)
                result.push_back(node->val);
            else{
                TreeNode * left = NULL;
                if(node->right != NULL){
                    myStack.push(node->right);
                    node->right = NULL;
                }
                if(node->left != NULL){
                    left = node->left;
                    node->left = NULL; 
                }
                myStack.push(node);
                if(left != NULL)
                    myStack.push(left);
            }
        }
        return result;
    }
};

Note

To solve the problem, I use a stack to save the node of the tree.