#### clueless coding// TODO: be smarter

Cracking the Coding Interview Elements of Programming Interviews Programming Interviews Exposed # 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);
}

``````