[Solved] Pointers/Class C++

You need a doubly-linked list. This list uses a node class, in this case you can call it train. Each node has a name, as well as next and previous node. The list class will store the nodes.

The example below is a simple version where all the members are public. You can improve it by declaring next, prev, head, tail as private, then provide public methods to access them.

The list should also cleanup after itself. In add method there is a call to train *node = new train(s). This memory should be freed in destructor using delete. You have to walk the list and delete the memory for each node.

See also these references:
https://en.wikipedia.org/wiki/Doubly_linked_list
http://www.dailyfreecode.com/Code/double-linked-list-cpp-3422.aspx

class train
{
public:
    string name;
    train *next, *prev;
    train(const string &s) {name = s; next = prev = nullptr;}
};

class linked_list
{
public:
    train *head, *tail;
    linked_list() { head = tail = nullptr;  }
    linked_list() { /*add cleanup routine*/ }
    train* add(const string &s)
    {
        train *node = new train(s);
        if(!head) {
            head = tail = node;
        }
        else {
            node->prev = tail;
            tail->next = node;
            tail = node;
        }
        return node;
    }
};

int main()
{
    linked_list list;
    train *walk, *node = nullptr;
    string name;
    while(true) {
        char choice="a";
        if(node) {
            cout << "(A)dd, (L)ist, (N)ext, (P)revious, (Q)uit ?\n";
            cin >> choice;
            choice = tolower(choice);
        }

        switch(choice) {
        case 'a': 
            cout << "enter name:\n";
            cin >> name;
            node = list.add(name);
            break;
        case 'l': 
            cout << "list:\n";
            walk = list.head;
            while(walk) {
                cout << walk->name << "\n";
                walk = walk->next;
            }
            break;
        case 'n':
            if(node->next) {
                node = node->next;
                cout << "next: " << node->name << "\n";
            }
            break;
        case 'p':
            if(node->prev) {
                node = node->prev;
                cout << "previous: " << node->name << "\n";
            }
            break;
        default: break;
        }
        if(choice == 'q')
            break;
    }
    return 0;
}