Implementation of Stack using Linked LIst in C++

#include <iostream>

#include <cstdlib>

using namespace std;

struct Node {

    int data;

    Node* next;

};

Node* top = NULL; // Global stack top pointer

void linkedListTraversal(Node* ptr) {

    while (ptr) { // Fixed: Correct loop condition

        cout << "Element: " << ptr->data << endl;

        ptr = ptr->next;

    }

}

int isEmpty(Node* top) {

    return (!top);

}

int isFull(Node* top) {

    Node* p = (Node*) malloc(sizeof(Node));

    if (!p) {

        return 1; // Stack is full (memory can't be allocated)

    } else {

        free(p);

        return 0;

    }

}

Node* push(Node* top, int x) {

    Node* n = new Node;

    if (!n) {

        cout << "Stack Overflow" << endl;

        return top;

    }

    n->data = x;

    n->next = top;

    top = n;

    return top;

}

int pop() {

    if (isEmpty(top)) {

        cout << "Stack Underflow" << endl;

        return -1;

    } else {

        Node* n = top;

        int x = n->data;

        top = top->next;

        free(n); // You used malloc in isFull(), so free() is OK here

        return x;

    }

}

int main() {

    top = push(top, 78);

    top = push(top, 7);

    top = push(top, 8);

    int element = pop();

    cout << "Popped element: " << element << endl;

    linkedListTraversal(top);

    return 0;

}