LintCode题解之Search Range in Binary Search Tree

1、题目描述

2、问题分析

首先将二叉查找树使用中序遍历的方式将元素放入一个vector，然后在vector 中截取符合条件的数字。

3、代码

 1 /**
 2  * Definition of TreeNode:
 3  * class TreeNode {
 4  * public:
 5  *     int val;
 6  *     TreeNode *left, *right;
 7  *     TreeNode(int val) {
 8  *         this->val = val;
 9  *         this->left = this->right = NULL;
10  *     }
11  * }
12  */
13 
14 class Solution {
15 public:
16     /**
17      * @param root: param root: The root of the binary search tree
18      * @param k1: An integer
19      * @param k2: An integer
20      * @return: return: Return all keys that k1<=key<=k2 in ascending order
21      */
22     vector<int> searchRange(TreeNode * root, int k1, int k2) {
23         // write your code here
24         vector<int> num ;
25         inorder(num, root);
26         
27         
28         
29         vector<int> res;
30         if( num.size() == 0)
31             return res;
32         int i = 0;
33         int j = num.size() - 1;
34         while( num[i] < k1) i++;
35         while( num[j] > k2) j--;
36         
37         for(int k=  i; k <= j; k++){
38             res.push_back(num[k]);
39         }
40         
41         return res;
42         
43     }
44     
45     void  inorder(vector<int>& nums , TreeNode *root){
46         if( root != NULL ){
47             inorder(nums, root->left);
48             nums.push_back(root->val);
49             inorder(nums,root->right);
50         }else {
51             return ;
52         }
53             
54         
55       
56     }
57     
58 };