main.cpp

#include "stack.h"

using namespace std;

int main()
{
	Stack s1(10);
	Stack s2(100);
	
	s1.push(100);
	s1.push(200);
	s1.push(300);
	
	cout << "s1 1st pop(): " << s1.pop() << '\n';
	cout << "s1 2nd pop(): " << s1.pop() << '\n';
	cout << "s1 3rd pop(): " << s1.pop() << '\n';
	
	return 0;
}

stack.cpp

#include "stack.h"

Stack::Stack(int size)
{
	pArr = new int[size];
	assert(pArr);
	this->tos = 0;
	this->size = size; 	
}

Stack::~Stack()
{
	delete [] this->pArr;
}
	
void Stack::push(int data)
{
	assert(this->tos != this->size);
	pArr[tos++] = data;
}

int Stack::pop()
{
	assert(this->tos != 0);
	return pArr[--tos];
}

stack.h

#ifndef STACK_H
#define STACK_H

#include <iostream>
#include <cassert>

class Stack {
private:
	int *pArr;
	int tos;
	int size;
	
public:
	Stack(int size = 0);
	~Stack();
	
	void push(int data);
	int pop();
};

#endif