leetcode

0 class Solution {

1 public:

2 TreeNode *mergeTrees(TreeNode *root1, TreeNode *root2) {

3 if (!root1 && !root2) return nullptr;

4 if (!root2)

5 return new TreeNode(root1->val, mergeTrees(root1->left, nullptr),

6 mergeTrees(root1->right, nullptr));

7 if (!root1)

8 return new TreeNode(root2->val, mergeTrees(nullptr, root2->left),

9 mergeTrees(nullptr, root2->right));

10 return new TreeNode(root1->val + root2->val, mergeTrees(root1->left, root2->left),

11 mergeTrees(root1->right, root2->right));

12 }

13 };