LeetCode Invert Binary Tree

Description

nvert a binary tree.

4
/
2 7
/ \ /
1 3 6 9
to
4
/
7 2
/ \ /
9 6 3 1

The original problem is here.

The original code is here.

My Solution

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

/*
*Invert Binary Tree
*Author: shuaijiang
*Email: zhaoshuaijiang8@gmail.com
*/
#include<iostream>
#include<math.h>
#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:
    TreeNode* invertTree(TreeNode* root) {
        TreeNode *temp;
        if(root == NULL)
            return root;
        temp = root->left;
        root->left  = root->right;
        root->right = temp;
        
        root->left  = invertTree(root->left);
        root->right = invertTree(root->right);
        
        return root;
    }
};

Note

In the solution, recursion is needed.