[leetcode] Convert Sorted List to Binary Search Tree

public class Solution {
    public TreeNode sortedListToBST(ListNode head) {
        int len = 0;
        ListNode p = head;
        while (p != null) {
            len++;
            p = p.next;
        }
        ListNode[] wrap = new ListNode[1];
        wrap[0] = head;
        return SLtoBST(wrap, 0, len);
    }

    private TreeNode SLtoBST(ListNode[] wrap, int start, int end) {
        if (start >= end)
            return null;
        int mid = start + (end - start) / 2;
        TreeNode left = SLtoBST(wrap, start, mid);
        TreeNode root = new TreeNode(wrap[0].val);
        root.left = left;
        wrap[0] = wrap[0].next;
        root.right = SLtoBST(wrap, mid + 1, end);
        return root;
    }

    public static void main(String[] args) {
        ListNode head = ListUtils.makeList(1);
        TreeNode root = new Solution().sortedListToBST(head);
    }

}