#ifndef _STACKLI_H_
#define _STACKLI_H_

#include <stdlib.h>
#include "Except1.h"


// Stack class -- linked list implementation
//
// CONSTRUCTION: with no parameters
//
// ******************PUBLIC OPERATIONS*********************
// void push( x )        --> Insert x
// void pop( )           --> Remove most recently inserted item
// Object top( )         --> Return most recently inserted item
// Object topAndPop( )   --> Return and remove most recently inserted item
// bool isEmpty( )       --> Return true if empty; else false
// void makeEmpty( )     --> Remove all items
// ******************ERRORS********************************
// Underflow thrown as needed

template <class Object>
class Stack
{
  public:
    Stack( );
    Stack( const Stack & rhs );
    ~Stack( );

    bool isEmpty( ) const;
    const Object & top( ) const;

    void makeEmpty( );
    void pop( );
    void push( const Object & x );
    Object topAndPop( );

    const Stack & operator=( const Stack & rhs );

  private:
    struct ListNode
    {
        Object   element;
        ListNode *next;

        ListNode( const Object & theElement, ListNode * n = NULL )
          : element( theElement ), next( n ) { }
    };

    ListNode *topOfStack;
};

#endif