/**
*  This class contains the linked list.
*  It also contains the constructor, wich
*  generates a new list called myList
*  
*       @author Christian Ohlsson, Karlstad university 1999
*       @version 1.0.0
*/
public class  List { 
  Element first, last;  
 
/**
*  This is the constructor of the list.
*  What it basically do is to set
*  the two Elements constructed before
*  to null.
*/
  public List() { first = last = null; } 
 
/**
*  This function returns the first Element 
*  in the list.
*/
  public Element first() { return first; } 
 
/**
*  This function returns the last Element 
*  in the list.
*/
  public Element last() { return last; } 
 
/**
*  If the first element in the List is null, 
*  it returns true, that is, there's no Elements 
*  in the List.
*/
  public boolean empty() { return first==null; } 
 
/**
*  This function recives a number and it traverses
*  though the List until that number is reached
*  and then returns the Element on that location
*/
  public Element getElement(int number) {
    Element e = first;
    int antal = 0;
    while (antal<number) { 
      antal++; 
      e = e.suc; 
    } 
    return e; 
  }     
 
/**
*  This function initialize a number to zero
*  and the traverses though the List until
*  it reaches the end and than returns
*  the number of elements.
*/
  public int cardinal() { 
    int antal = 0; 
    Element e = first; 
    while (e!=null) { 
      antal++; 
      e = e.suc; 
    } 
    return antal; 
  } 
}