Binary Tree Inorder Traversal

https://leetcode.com/problems/binary-tree-inorder-traversal/

递归中序遍历

 1 /**
 2  * Definition for a binary tree node.
 3  * struct TreeNode {
 4  *     int val;
 5  *     TreeNode *left;
 6  *     TreeNode *right;
 7  *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 8  * };
 9  */
10 class Solution {
11 public:
12     vector<int> inorderTraversal(TreeNode* root) {
13         vector<int> res;
14         inorderVisit(root,res);
15         return res;
16         
17     }
18     void inorderVisit(TreeNode * temp,vector<int>& res)
19     {
20         if(temp==NULL)
21             return;
22         if(temp->left!=NULL)
23             inorderVisit(temp->left,res);
24         res.push_back(temp->val);
25         if(temp->right!=NULL)
26             inorderVisit(temp->right,res);
27     }
28 };