[力扣题解] 617. 合并二叉树

题目：617. 合并二叉树

思路

递归法遍历，随便一种遍历方式都可以，以前序遍历为例；

代码

class Solution {
public:TreeNode* mergeTrees(TreeNode* root1, TreeNode* root2) {if(root1 == NULL){return root2;}if(root2 == NULL){return root1;}root1->val += root2->val;root1->left = mergeTrees(root1->left, root2->left);root1->right = mergeTrees(root1->right, root2->right);return root1;}
};