#include <iostream>

struct Node
{
    int value;
    Node* next;
};

// TODO: Implement the Iterator class here

class List
{
public:
    List()
        : top {}
    {}

    ~List()
    {
        while (top != nullptr)
        {
            Node* tmp {top->next};
            delete top;
            top = tmp;
        }
    }

    void add(int i)
    {
        top = new Node{i, top};
    }

    // TODO: Extend the List class here.

private:
    Node* top;
};

int main()
{
    List list {};
    list.add(3);
    list.add(2);
    list.add(7);
    list.add(4);
    list.add(1);

    *(++list.begin()) = 12; 
    
    for (auto it {list.begin()}; !(it == list.end()); ++it)
    {
        std::cout << *it << " ";
    }
    std::cout << std::endl;
}