leetcode 94. 二叉树的中序遍历

题目如下

做了那么多道难题，给自己放放松。

通过代码

/*** 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:void in(TreeNode* root,vector<int> &ans){if(root == nullptr)return;in(root->left,ans);ans.push_back(root->val);in(root->right,ans);}vector<int> inorderTraversal(TreeNode* root) {vector<int> ans;in(root,ans);return ans;}
};