stack.cpp

#include <iostream>
using namespace std;

class Stack {
public:
    int *a;
    int top;
    int size;

    Stack(int data) {
        a = new int[data];
        top = -1;
        size = data;
    }

    void push(int b) {
        if (top >= size - 1) {
            cout << "Stack is full" << endl;
        } else {
            top++;
            a[top] = b;
            cout << b << " pushed to stack." << endl;
        }
    }

    int peek() {
        if (isempty()) {
            cout << "Stack is empty" << endl;
            return -1;
        }
        return a[top];
    }

    void pop() {
        if (isempty()) {
            cout << "Stack is empty nothing to pop." << endl;
        } else {
            cout << a[top] << " popped from stack" << endl;
            top--;
        }
    }

    bool isempty() {
        return top == -1;
    }
};

int main() {
    Stack s(3);

    s.push(4);
    s.push(5);
    s.push(9);
    s.push(20); 

    cout << "Top element: " << s.peek() << endl;

    s.pop();
    s.pop();
    s.pop();
    s.pop(); 

    return 0;
}