树783. 二叉搜索树节点最小距离

Posted 2021-02-20 ocpc

题目:

 

 

解答：

同题目530。

 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     void inOrder(TreeNode *root, vector<int> &ret)
13     {
14         if (NULL == root)
15         {
16             return;
17         }
18 
19         inOrder(root->left, ret);
20         ret.push_back(root->val);
21         inOrder(root->right, ret);
22     }
23 
24     int minDiffInBST(TreeNode* root) 
25     {
26         int res = INT_MAX;
27         vector<int> ret;
28         vector<int> diff;
29 
30         inOrder(root, ret);
31 
32         for (int i = 1; i < ret.size(); ++i)
33         {
34             diff.push_back(ret[i] - ret[i-1]);
35         }
36         for (int i = 0; i < diff.size(); ++i)
37         {
38             res = std::min(res, diff[i]);
39         }
40 
41         return res;
42 
43     }
44 };