108. Convert Sorted Array to Binary Search Tree java solutions

Given an array where elements are sorted in ascending order, convert it to a height balanced BST.

Subscribe to see which companies asked this question

 1 /**
 2  * Definition for a binary tree node.
 3  * public class TreeNode {
 4  *     int val;
 5  *     TreeNode left;
 6  *     TreeNode right;
 7  *     TreeNode(int x) { val = x; }
 8  * }
 9  */
10 public class Solution {
11     public TreeNode sortedArrayToBST(int[] nums) {
12         return BST(nums,0,nums.length-1);
13     }
14     
15     public TreeNode BST(int[] num,int low, int high){
16         if(low > high) return null;
17         int mid = (low + high)/2;
18         TreeNode node = new TreeNode(num[mid]);
19         node.left = BST(num,low,mid-1);
20         node.right = BST(num,mid+1,high);
21         return node;
22     }
23 }

因为数组已经是有序的了，因此使用递归进行处理即可。