// A class's description to be provided by student
// Fill in code in ALL commented areas

public class LinkedList {
   // Defined Node class
   private class Node {
      private Object Data = null;
      private Node Next = null;
      public Node() {
          Data = null;
          Next = null;
      }
      public Node(Object element) {
          Data = element;
      }
      public Node(Object o, Node n) {
          Data = o;
          Next = n;
      }
      public void setNext(Node n) {
         Next = n;
      }
      public Node getNext() {
         return Next;
      }
      public Object getElement() {
         return Data;
      }
      public void setElement(Object element) {
         Data = element;
      }
   }

   // Internal data for LinkedList
   private Node head = null;
   private Node current = null;
   private int size = 0;

   // LinkedList constructor
   public LinkedList() {
      head = null;
      current = head;
   }

   // Move the current position forward one position
   public void forward() {

   }

   // Move the current position backward one position
   public void backward() {

   }

   // Get current object's data element
   public Object currentData() {

   }


   // Add object to the first of the list
   public void addFirst(Object o) {

   }


   // resetCurrent at the first position
   public void resetCurrent() {

   }

   // Add object to the last of the list
   public void addLast(Object o) {

   }

   // Add an object o before the current position
   public void insertBefore(Object o) {

   }

   // Add an object o after the current position
   public void insertAfter(Object o) {

   }

   // Get first object
   public Object getFirst() {

   }

   // Get last object
   public Object getLast() {

   }

   // Remove the first object
   public Object removeFirst(){

   }

   // Remove the last object
   public Object removeLast() {

   }

   // Remove object o from the list
   public void remove(Object o) {

   }

   // Returns the number of elements on the list
   public int size() {
      return size;
   }

   // Is the list emptied?
   public boolean isEmpty() {

   }

   // Display a content of a list
   public String toString() {
      String r = "( HEAD -> ";
      // Node l = head.getNext();
      Node l = head;
      while (l != null) {
         r = r + l.getElement() + " -> " ;
         l = l.getNext();
      }
      return  r + " )";
   }

   public static void main(String args[]) {
      LinkedList lst = new LinkedList();
      // creat instances for testing
      CsusStudent instance1 = new CsusStudent("John Doe 1", 1, "1 Somewhere", "916-555-1211", "johndoe1@somewhere.com");
      CsusStudent instance2 = new CsusStudent("John Doe 2", 2, "2 Somewhere", "916-555-1212", "johndoe2@somewhere.com");
      CsusStudent instance3 = new CsusStudent("John Doe 3", 3, "3 Somewhere", "916-555-1213", "johndoe3@somewhere.com");
      CsusStudent instance4 = new CsusStudent("John Doe 4", 4, "4 Somewhere", "916-555-1214", "johndoe4@somewhere.com");
      CsusStudent instance5 = new CsusStudent("John Doe 5", 5, "5 Somewhere", "916-555-1215", "johndoe5@somewhere.com");
      CsusStudent instance6 = new CsusStudent("John Doe 6", 6, "6 Somewhere", "916-555-1216", "johndoe6@somewhere.com");
      CsusStudent instance7 = new CsusStudent("John Doe 7", 7, "7 Somewhere", "916-555-1217", "johndoe7@somewhere.com");
      CsusStudent instance8 = new CsusStudent("John Doe 8", 8, "8 Somewhere", "916-555-1218", "johndoe8@somewhere.com");
      CsusStudent instance9 = new CsusStudent("John Doe 9", 9, "9 Somewhere", "916-555-1219", "johndoe9@somewhere.com");

      // begin adding instance1 to the list


      // test forward and backward for single entry


      // now add instance2 and instance3 via addFirst and instance4, instance5, instance6 via addLast


      // move current forward a few times

      // insert instance 9 after

      // remove instance9


      // print out the first and last entries
      System.out.println("Show the first entry and last entry:");


      // print out the whole list
      System.out.println("Show the whole list:");


      // remove entries starting from the last entry
      System.out.println("Check for the content of the emptied list");

   }
}