/* ======================================================================
   The List object that I use to demo the recursive "insert( )" method
   ====================================================================== */
class List
{
   int  value;
   List next;

   public List(int x)
   {
      value = x;
   }
}


public class InsertList
{
   /* ----------------------------------------------------
      main: call insert(head, new List( ))
            and prints resulting list
      ---------------------------------------------------- */
   public static void main(String[] args)
   {
      int[] inp = {1, 9, 3, 8, 5, 6, 7};

      List head = null;

      for ( int i = 0; i < inp.length; i++ )
      {
         System.out.print("List before inserting: " + inp[i] + ": ");
         print(head);
         System.out.println();

	 head = insert(head, new List(inp[i]) );

         System.out.print("List after  inserting: " + inp[i] + ": ");
         print(head);
         System.out.println("\n");
      }
   }

   /* =================================================
      The recursive "insert at tail in list" method
      ================================================= */
   public static List insert( List head, List e )
   {
      List helpSol;

      /* -----------------------------------------------------
	  Base case: easy insert at the tail of an empty list
         ----------------------------------------------------- */
      if ( head == null )
      {
         e.next = null;     // Mark e as the last list elem
	 return(e);         // e is the first list elem !
      }
      else
      {

         helpSol = insert( head.next, e ); // Have "someone else" solve
                                           // this smaller problem

         /* ===========================================================
            Solve the problem USING the solution of a smaller problem
	    =========================================================== */
         head.next = helpSol;     // Construct MY solution using helpSol
         return head;             // Return MY solution
      }
   }

   /* ======================================
      Print the list at h
      ====================================== */
   public static void print(List h)
   {
      while ( h != null )
      {
         System.out.print(h.value + " ");
         h = h.next;
      }
   }

}