https://leetcode.cn/problems/merge-two-binary-trees/
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode() : val(0), left(nullptr), right(nullptr) {}
* TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
* TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
* };
*/
class Solution {
public:
TreeNode* mergeTrees(TreeNode* root1, TreeNode* root2)
{
if(root1 == nullptr && root2 == nullptr)
{
return nullptr;
}
else if(root1 == nullptr && root2)
{
return root2;
}
else if(root2 == nullptr && root1)
{
return root1;
}
else
{
root1->val = root1->val + root2->val;
root1->left = mergeTrees(root1->left,root2->left);
root1->right = mergeTrees(root1->right,root2->right);
}
return root1;
}
};