import collections.Stack;
import collections.impl.LList;
import java.util.Enumeration;

public class LLStackTest {
    public static void main(String[] args) {
        // create linked list, but treat it like a Stack
        LList list = new LList();
        Stack s = list;
        s.push(new Integer(3));
        s.push(new Integer(4));
        s.push(new Integer(5));

        // Test height()
        if ( s.height()!=3 )
            System.out.println("incorrect height");
        else
            System.out.println("correct: height is 3");
        
        // Test the enumeration (pretend it's a list again)
        // Note how different perspectives on the same object are useful.
        Enumeration e = list.elements();
        for (; e.hasMoreElements();) {
            System.out.println(e.nextElement());
        }

        // Test pop(): compute 3*(4+5) via "3 4 5 + *" in RPN notation
        int a = ((Integer)s.pop()).intValue();
        int b = ((Integer)s.pop()).intValue();
        s.push( new Integer(a+b) );
        a = ((Integer)s.pop()).intValue();
        b = ((Integer)s.pop()).intValue();
        int result = a * b;
        System.out.println("result, " + result + ", should be 27");
        
        if ( s.height()!=0 ) System.out.println("incorrect stack height");
        
        /* Code that is commented here out won't compile since a Stack
         * is a limited perspective on a LLStack implementation.
         *      Stack s2 = s;
         *      s2.includes("Frank");
         */
    }
}