LeetCode: Convert Sorted Array to Binary Search Tree (DFS using Binary Search techniques)

https://leetcode.com/problems/convert-sorted-array-to-binary-search-tree/, problem statement:

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

Since the tree has to be height balanced, the array needs to be divided in half all the time in order to create the BST properly. It will be a standard DFS and as we go down split the array in half similar to binary search techniques. We only visit the elements of the array once, hence it is O(n). Code below, cheers, Marcelo.

    public class Solution
    {
        public TreeNode SortedArrayToBST(int[] nums)
        {
            return SortedArrayToBSTInternal(nums, 0, nums.Length - 1);
        }

        private TreeNode SortedArrayToBSTInternal(int[] nums, int left, int right)
        {
            //Bases: null and leaf
            if (nums == null || nums.Length == 0 || left > right) return null;
            if (left == right) return new TreeNode(nums[left]);

            //Induction
            int mid = (left + right) / 2;
            TreeNode node = new TreeNode(nums[mid]);
            node.left = SortedArrayToBSTInternal(nums, left, mid - 1);
            node.right = SortedArrayToBSTInternal(nums, mid + 1, right);
            return node;
        }
    }