cc150_2.2

Implement an algorithm to find the kth to last element of a singly linked list.

LinkedListNode  nthToLast(LinkedListNode head, int k) {
  if(k <= 0) return null;
  LinkedListNode prev = head;
  LinkedListNode cur = head;
  while(cur && k > 1){    
     cur = cur.next;
     k--;
  }
  if(!cur) return null;
  while(cur.next){
     cur = cur.next;
     prev = prev.next;
  }

 return prev;
}