stack.cpp

#include <bits/stdc++.h>
using namespace std;
#define MAX 1000
class Stack {
    int top;

public:
    int a[MAX];

    Stack() { top = -1; }
    bool push(int x);
    int pop();
    int peek();
    bool isEmpty();
};

bool Stack::push(int x)
{
    if (top >= (MAX - 1)) {
        cout << " OVERFLOW";
        return false;
    }
    else {
        a[++top] = x;
        cout << x << " PUSHED\n";
        return true;
    }
}

int Stack::pop()
{
    if (top < 0) {
        cout << "UNDERFLOW";
        return 0;
    }
    else {
        int x = a[top--];
        return x;
    }
}
int Stack::peek()
{
    if (top < 0) {
        cout << "EMPTY";
        return 0;
    }
    else {
        int x = a[top];
        return x;
    }
}

bool Stack::isEmpty()
{
    return (top < 0);
}

int main()
{
    class Stack s;
    s.push(10);
    s.push(20);
    s.push(30);
    cout << s.pop() << " POPPED\n";

    return 0;
}