// Name:
// Lab Section:
// Primary TA:
// Email:
// Date:
// CS101 Lab 8
// IntStack.java

/*
 * Instructions
 *   Decide whether IntStack should extend Stack
 *       If it does, delete those methods that you have in Stack
 *   Implement the methods for this class and test them
 */

import cs101.terminal.*;

public class IntStack {

   
   public IntStack() {  }

   public boolean isEmpty() {
      return true;
   }

   public void push(int n) {
   }

   public Integer popInteger() {
      return null;
   }

   public int getTop() {
      throw new Error("getTop not implemented yet!");
   }

   public void add() {
   }

   public void mpy() {
   }

   public void neg() {
   }

   public void sub() {
   }

   public void dup() {
   }

   public void prt() {
   }

   public String toString() {
     return "fill me in or delete me";
   }
   
   public static void selfTest() {
      IntStack is = new IntStack();
      is.push(1);     is.prt();
      is.push(27);    is.prt();
      is.push(2);     is.prt();
      is.sub();       is.prt();
      is.dup();       is.prt();
      is.add();       is.prt();
      is.push(2);     is.prt();
      is.mpy();       is.prt();
      is.add();       is.prt();
      is.prt();
      is.add();       // will cause stack underflow
   }

   public static void main(String args[]) { selfTest(); }
}