// SaveLink class in a file  Link.java 

public class Link
{
  public int data;
  public Link next;
 
  public Link()
  {
     next=null;
  }

  public Link(int item)
  {
    data=item;
    next=null;
  }

  public void displayLink()
  {
    System.out.println(data+" ");
  }
}// class Link
//////////////////////////////////////////////////////////////////////////////////

//Save LL class in a file as LL.java

import java.util.Random;

public class LL
{ 
   private Link list;
   
   public LL()          // constructor creates linked list
   {  Link curr;        // of randomly selected size and
      list=null;        // random values for data in each link  
      int ndata;
      Random r = new Random();
      int n = Math.abs(r.nextInt()) %10;
      for (int i=1; i<=n; i++)
          {
          curr=new Link();
          ndata = Math.abs(r.nextInt()) %10;           
          curr.data=ndata;
          curr.next=list;
          list=curr;  
          }     
   }


   private void traverse(Link first)
    {
       if (first!= null)
          {
          System.out.println(first.data);
          traverse(first.next);
          } 
    } 

   public void llTraverse()
   {
     traverse(list);
   }


   public int llCountNodes()
   {
    return countNodes(list);
   }


   private int countNodes(Link first)
   {
      if (first == null)
        return 0;
      else
	return 1 + countNodes(first.next);
   }


   private int countZeroNodes(Link first)
   {
      if (first == null) 
        return 0;
      else if (first.data == 0)
        return 1 + countZeroNodes(first.next);
      else
	 return countZeroNodes(first.next);
   }


   public int llCountZeroNodes()
   {
        return countZeroNodes(list);
   }

   private int countItems(Link first, int item)
   {
     if (first == null) 
       return 0;
     else if (first.data == item)
       return 1 + countItems(first.next, item);
     else
       return countItems(first.next, item);
    }


    public int llCountItems(int item)
    {
       return countItems(list, item);
    }


    private boolean itemInList(Link first, int item)
    {
       if (first == null) 
           return false;
       else if (first.data == item)
           return true;
       else
	   return itemInList(first.next, item);
    }

    public boolean llItemInList(int item)
    { 
       return itemInList(list, item);
    }

   

    private int sumData(Link first )
    {
      if (first == null) 
	 return 0;
      else
         return  first.data + sumData(first.next);
    }

    public int llSumData()
    {
       return sumData(list);
    }
} // class LL    LinkedList
//////////////////////////////////////////////////////////////////////////////////

// saveTLL class in a file TLL.java

class TLL
{ // testing linked list examples
  public static void main(String[] args)
  {
      int n;
      LL l = new LL(); 
      l.llTraverse();
     System.out.println( "countNodes n = " +l.llCountNodes());
     System.out.println( "countZeroNodes n = " +l.llCountZeroNodes());
     System.out.println( "countItem 5 = " +l.llCountItems(5));
     if (l.llItemInList(5))
       System.out.println("5 in list" );
     else
       System.out.println("5 not in list" );
     System.out.println();
     if (l.llItemInList2(5))
        System.out.println("5 in list" );
     else
        System.out.println("5 not in list" );
     System.out.println();
  
     System.out.println("Sum of Data in LL" + l.llSumData());    
  } //main
} // TLL