【树】897. 递增顺序查找树

 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 
13     void inorder(TreeNode *root, vector<int> &ret)
14     {
15         if (NULL == root)
16         {
17             return;
18         }
19 
20         inorder(root->left, ret);
21         ret.push_back(root->val);
22         inorder(root->right, ret);
23     }
24 
25     TreeNode* increasingBST(TreeNode* root) 
26     {
27         vector<int> result;
28         inorder(root, result);
29 
30         TreeNode *ans = new TreeNode(0);
31         TreeNode *cur = ans;
32         for (int v: result) 
33         {
34             cur->right = new TreeNode(v);
35             cur = cur->right;
36         }
37         return ans->right;
38         
39     }
40 };