stack

#include <iostream>

using namespace std;

struct node
{
    int number;
    node *next;
};

void push(node **top, int n)
{
    node *ptr = new node;
    ptr->number = n;
    if (top == NULL)
        *top = ptr;
    else
    {
        ptr->next = *top;
        *top = ptr;
    }
}

int mult(node *top)
{
    node *ptr = top;
    int res = 1;
    while (ptr)
    {
        res = res * ptr->number;
        ptr = ptr->next;
    }
    return res;
}

void print(node *top)
{
    node *ptr = top;
    while (ptr)
    {
        cout << ptr->number << " ";
        ptr = ptr->next;
    }
    cout << endl;
}

int main()
{
    node *top = NULL;
    int elem_quan;
    int enter_n;
    cout << "enter number of elems: ";
    cin >> elem_quan;
    for (int i = 0; i < elem_quan; i++)
    {
        cin >> enter_n;
        push(&top, enter_n);
    }
    print(top);
    push(&top, mult(top));
    print(top);
    return 0;
}