#include <assert.h>
#include <iostream.h>

class int_stack {
	class node {
	public:
		int data;
		node* next;
	};
	node* new_node(int d, node* n);
	node* top;
public:
	// Note, some of the access functions are defined inline
	void init(int nitems = 100) 
	    { top = NULL; }
	void push(int x) 
	    { top = new_node(x, top); }
	int pop();
	bool isempty() 
	    { return( top == NULL ); }
	bool isfull() 
	    { return( false ); }
};