# LeetCode 108. Convert Sorted Array to Binary Search Tree: Java Solution

## Problem Statement

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

For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the two subtrees of every node never differ by more than 1.

```
Function Signature (Java):
TreeNode sortedArrayToBST(int[] nums)
Inputs:
nums = [-10,-3,0,5,9]
Outputs:
0
/ \
-3 9
/ /
-10 5
Note that this is only one valid solution - there are other configurations that could work.
```

## TL;DR Code Solution

```
public TreeNode helper(int[] nums, int left, int right) {
if (left > right) {
return null;
}
int mid = (left + right) / 2;
TreeNode root = new TreeNode(nums[mid]);
root.left = helper(nums, left, mid - 1);
root.right = helper(nums, mid + 1, right);
return root;
}
public TreeNode sortedArrayToBST(int[] nums) {
if (nums.length == 0)
return null;
return helper(nums, 0, nums.length - 1);
}
```