public static SLNode nthToLast2(SLNode head, int k, IntWrapper i) {
if (head.next == null) return head;
SLNode node = nthToLast2(head.next, k, i);
i.value = i.value + 1;
if (i.value == k) return head;
return node;
}
public static SLNode nthToLast2(SLNode head, int k, IntWrapper i) {
if (head.next == null) return head;
SLNode node = nthToLast2(head.next, k, i);
i.value = i.value + 1;
if (i.value == k) return head;
return node;
}