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


class int_stack {
	int sz;
	int top;
	int* stack;
public:
	// Note that the default constructor makes sz, top and *stack
	// Note that the stack itself is built by the init function
	~int_stack () ;
	void init(int nitems);		// specified size
	void init();				// default size
	void push(int );
	int pop();
	bool isempty();
	bool isfull();
};