#include "stack.h"
stack::stack(){
	//This is the default constructor
	//In the absence of user specification, assume
	//the size arbitrarily 
	size = 50;
	tos = 0;
	st = new datatype[size];
}

stack::stack(int s){
	//Overloaded constructor
	//Create the stack according to user specification
	size = s;
	tos = 0;
	st = new datatype[size];
}

stack::~stack(){
	//Deallocate everything that was dynamically allocated
	delete [] st;
}

void stack::push(datatype item){
	if(tos==size) return;
	st[tos]=item;
	tos++;
}

void stack::pop(datatype &item){
	if(tos==0) return;
	tos--;
	item=st[tos];
}

bool stack::is_empty(){
	return (tos==0);
}