import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import java.util.concurrent.locks.Condition;
import java.util.ArrayList;

class Bord {
    private ArrayList<String> liste = new ArrayList<>();
    private Lock bordLaas = new ReentrantLock();
    private Condition ikkeTom = bordLaas.newCondition();
    private int antallFerdige = 0;
    private int antallBarista;

    public Bord(int antallBarista) {
        this.antallBarista = antallBarista;
    }

    public void server(String kaffe) {
        bordLaas.lock();
        try {
            if (kaffe.equals("Tomt")) {
                antallFerdige++;
            }
            else {
                liste.add(kaffe);
            }
            ikkeTom.signal();
        }
        finally {
            bordLaas.unlock();
        }
    }

    public String hentKaffe() {
        bordLaas.lock();
        try {
            while (liste.isEmpty()) {
                if (antallBarista == antallFerdige) {
                    ikkeTom.signalAll();
                    return "Tomt";
                }
                ikkeTom.await();
            }
            return liste.remove(0);
        }
        catch (InterruptedException e) {
            System.out.println("Traaden ble avbrutt");
        }
        finally {
            bordLaas.unlock();
        }
        return "Tomt";
    }
}