//IntList.java - a linked list of integers

class IntList {

  IntListElement head;
  IntListElement current;//previous;

  /* Note that there is no constructor. */

  /* Instance methods: */

  int current(){return current.data;}

  boolean hasNext(){
    if(current != null) 
      return current.next != null;
    else
      return head != null;
  }

  int next(){
    if (current == null)
      current = head;
    else
      current = current.next;
    return current.data;
  }

  void insert(int value){
    IntListElement nle = new IntListElement(value);

    if(current != null){ // current points to a non-empty listmember
      IntListElement tmp = current.next;
      current.next = nle;
      nle.next = tmp;
      current = nle;
    }
    else if(head != null){// one element list
      current = nle;
      nle.next = head;
      head = current;
    }
    else {// empty list
      head = current = nle;
    }
    return;
  }

  /* We can only (easily) delete the node _after_
   * the current node, thus, we should move to a cell 
   * _before_ the head to be able to delete that node 
   * too.
   */

  void moveToHead(){current = null;}

  public String toString(){
    StringBuffer sb = new StringBuffer();
    IntListElement cell = head;

    while(cell != null){
      /* Observe the use of the StringBuffer */
      sb.append(cell.toString());
      sb.append("\n");
      cell = cell.next;
    }
    return sb.toString();
  }
}