public class Competition {

    private List<Athlete> runners;
    private BinarySearchTree<Athlete> leaderboard;
    private RaceSimulator sim;

    public Competition() {
        runners = new List<>();
        leaderboard = new BinarySearchTree<>();
        sim = new RaceSimulator();
    }

    public void newRunner(String name) {
        runners.append(new Athlete(name));
    }

    public void simulate() {
        runners.toFirst();
        while (runners.hasAccess()) {
            sim.simulate(runners.getContent());
            leaderboard.insert(runners.getContent());
            runners.next();
        }
    }

    public Athlete[] top3() {
        Athlete[] top = new Athlete[3];
        List<Athlete> inOrder = leaderboard.getInOrder();
        inOrder.toFirst();
        top[0] = inOrder.getContent();
        inOrder.next();
        if (!inOrder.hasAccess()){
            return top;
        }
        top[1] = inOrder.getContent();
        inOrder.next();
        if (!inOrder.hasAccess()){
            return top;
        }
        top[2] = inOrder.getContent();
        inOrder.next();
        return top;
    }
}