class IntSet11a extends IntSet11
{
// Adds a copy to sets implemented using linked lists
// Copy method uses iteration

 public IntSet11a()
 {
  super();
 }

 private IntSet11a(Cell l)
 {
  list=l;
 }
 
 public IntSet11a copy()
 {
  if(list==null)
     return new IntSet11a(null);
  else
     {
      Cell list1 = new Cell(list.first,null);
      Cell ptr1 = list1;
      for(Cell ptr=list; ptr.next!=null; ptr=ptr.next) 
         {
          ptr1.next = new Cell(ptr.next.first,null);
          ptr1 = ptr1.next;
         }
      return new IntSet11a(list1);
     }
 }
}