/* C++ program to implement basic stack
operations */
#include <bits/stdc++.h>

using namespace std;

 //defining max size of array
#define MAX 100000

class Stack {
    int top; //the variable which we gonna use

public:
    int a[MAX]; // Maximum size of Stack

    Stack() { top = -1; }
    //below are the four operations
    bool push(int x);
    int pop();
    int peek();
    bool isEmpty();
};

bool Stack::push(int x)
{
    if (top >= (MAX - 1)) {
        cout << "Stack Overflow";
        return false;
    }
    else {
        a[++top] = x; //increement top and assign value
        cout << x << " pushed into stack\n";
        return true;
    }
}

int Stack::pop()
{
    if (top < 0) {
        cout << "Stack Underflow";
        return 0;
    }
    else {
        int x = a[top--];//decreement top

        return x;
    }
}
int Stack::peek()
{
    if (top < 0) {
        cout << "Stack is Empty";
        return 0;
    }
    else {
        int x = a[top]; //simple enough
        return x;
    }
}

bool Stack::isEmpty()
{
    return (top < 0); //simple if else condition
}

// Driver program to test above functions
int main()
{
    class Stack s;
    s.push(10);
    s.push(20);
    s.push(30);
    cout << s.pop() << " Popped from stack\n";

    return 0;
}