617. Merge Two Binary Trees

class Solution {
public:
    TreeNode* mergeTrees(TreeNode* root1, TreeNode* root2) {
        if(root1 == nullptr)
        {
            return root2;
        }
        if(root2 == nullptr)
        {
            return root1;
        }

        auto merged = new TreeNode(root1 -> val + root2 -> val);
        merged->left = mergeTrees(root1->left, root2->left);
        merged->right = mergeTrees(root1->right, root2->right);

        return merged;
    }
};