Linked Lists in Classes - Program Not Working

[TweedleGun]

Hey there I'm having trouble with coding linked lists as a class. This is my "Lists.h" file:

#include <string>
#include <iostream>

using namespace std;

#ifndef LISTS_H
#define LISTS_H


class List {
    public:
        struct node {
            int entryNum, keyNum;
            string keyword[4];
            string actWord[2];
            string storyLine;
            node* next;
        };

        node* head;

        List();
        node* addNode(int);
        node* getNode(int);
        void display();
};

#endif // LISTS_H 

And this is my "Lists.cpp" file:

#include "Lists.h"

List::List() {
    head = new node;
    head->entryNum = 0;
    head->next = 0;
}


List::node* List::addNode(int n) {
    node* newNode = new node;
    newNode->entryNum = n;
    newNode->next = 0;

    node *cur = head;
    while(cur) {
        if(cur->next == 0) {
            cur->next = newNode;
            return newNode;
        }
    }
}

List::node* List::getNode(int n) {
    node *cur = head;
    while(cur) {
        if(cur->entryNum == n) {
            cout << "Found Node " << cur->entryNum << " in list." << endl;
            return cur;
        }
        cur = cur->next;
    }
    cout << "No Node " << n << " in list.\n";
}

void List::display() {
    node *cur = head;
    while(cur) {
        cout << "Node " << cur->entryNum << endl;
        cur = cur->next;
    }
}

I can execute this in main:

List story;
story.addNode(1);
story.display();

But whenever I try to add more than 1 node to my program:

List story;
story.addNode(1);
story.display();
story.addNode(2);
story.display();

it just stops working. It doesn't freeze up, it just sits there perpetually with the cursor blinking. I'm not overly confident with the concept of nesting structures, and I'm lucky I actually got it to sort of work, but it would be appreciated if someone could tell me what I'm doing wrong.

[MiiNiPaa]

    while(cur) {
        if(cur->next == 0) {

If first node -> next is not null pointer, it will go for another iteration of the loop and check first node again, and again, and again...

Also in your List::getNode you do not return anything if nothing was found. It will lead to stack corruption and obscure bugs. Return null pointer instead.

[TweedleGun]

Thank you sooo much, kind sir!! Fixed my problem, plus, I was getting those warnings after compile, but I didn't know what to do about them. Now I know :) Thank you

EDIT: One last question, if you have the time: The reason I'm using nested structures is because I didn't want each node to have the node-related functions unnecessarily. Is that what this code will achieve?