力扣-二叉树-617 合并二叉树
思路
先序遍历合并
代码
class Solution {
public:
TreeNode* mergeTrees(TreeNode* root1, TreeNode* root2) {
if(root1 != nullptr && root2 != nullptr){
root1->val += root2->val;
root1->left = mergeTrees(root1->left, root2->left);
root1->right = mergeTrees(root1->right, root2->right);
}else if(root1 == nullptr && root2 != nullptr){
root1 = root2;
}else if(root1 != nullptr && root2 == nullptr){
return root1;
}
return root1;
}
};