Leetcode 108. Convert Sorted Array to Binary Search Tree

public class Solution {
public TreeNode sortedArrayToBST(int[] nums) {
return helper(0, nums.length-1, nums);
}

// requires a balanced binary search tree, every time choosing mid of the array as root
public static TreeNode helper(int low, int high, int[] nums) {
if (low > high) return null;

int mid = low + (high-low)/2;
TreeNode root = new TreeNode(nums[mid]);

root.left = helper(low, mid-1, nums);;
root.right = helper(mid+1, high, nums);;

return root;
}
}