Today I have done leetcode's February LeetCoding Challenge with cpp.

February LeetCoding Challenge 18

Description

Invert Binary Tree

Given the root of a binary tree, invert the tree, and return its root.

Example 1:

Input: root = [4,2,7,1,3,6,9]
Output: [4,7,2,9,6,3,1]

Example 2:

Input: root = [2,1,3]
Output: [2,3,1]

Example 3:

Input: root = []
Output: []

Constraints:

• The number of nodes in the tree is in the range [0, 100].
• -100 <= Node.val <= 100

Solution

class Solution {
public:
  TreeNode* invertTree(TreeNode* root) {
    if(!root) return root;
    invertTree(root->left);
    invertTree(root->right);
    swap(root->left, root->right);
    return root;
  }
};

// Accepted
// 77/77 cases passed (0 ms)
// Your runtime beats 100 % of cpp submissions
// Your memory usage beats 79.47 % of cpp submissions (9.7 MB)