【树】530. 二叉搜索树的最小绝对差

 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     int getMinimumDifference(TreeNode* root) 
26     {
27         int res = INT_MAX;
28         vector<int> ret;
29         vector<int> diff;
30 
31         inOrder(root, ret);
32 
33         for (int i = 1; i < ret.size(); ++i)
34         {
35             diff.push_back(ret[i] - ret[i-1]);
36         }
37         for (int i = 0; i < diff.size(); ++i)
38         {
39             res = std::min(res, diff[i]);
40         }
41 
42         return res;
43     }
44 };