Array to BST

class Node {
    int data;
    Node left, right;

    Node(int item) {
        data = item;
        left = right = null;
    }
}

class Solution {
    public Node sortedArrayToBST(int[] nums) {
        if (nums == null || nums.length == 0)
            return null;

        return sortedArrayToBST(nums, 0, nums.length - 1);
    }

    private Node sortedArrayToBST(int[] nums, int start, int end) {
        if (start > end)
            return null;

        int mid = start + (end - start) / 2;
        Node node = new Node(nums[mid]);
        node.left = sortedArrayToBST(nums, start, mid - 1);
        node.right = sortedArrayToBST(nums, mid + 1, end);

        return node;
    }
}