invert a binary tree

#include <iostream>

struct TreeNode {
    int val;
    TreeNode* left;
    TreeNode* right;
    TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
};

void invertTree(TreeNode* root) {
    if (root == nullptr) {
        return;
    }

    // Swap left and right subtrees
    TreeNode* temp = root->left;
    root->left = root->right;
    root->right = temp;

    // Recursively invert left and right subtrees
    invertTree(root->left);
    invertTree(root->right);
}

int main() {
    // Example usage
    TreeNode* root = new TreeNode(1);
    root->left = new TreeNode(2);
    root->right = new TreeNode(3);
    root->left->left = new TreeNode(4);
    root->left->right = new TreeNode(5);
    root->right->left = new TreeNode(6);
    root->right->right = new TreeNode(7);

    std::cout << "Original tree:" << std::endl;
    // Print original tree (pre-inversion)
    // ...

    // Invert the binary tree
    invertTree(root);

    std::cout << "Inverted tree:" << std::endl;
    // Print inverted tree
    // ...

    return 0;
}