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

public class Romskip {
    private ArrayList<String> varer = new ArrayList<>();
    private final int KAPASITET = 5;

    private Lock l?s = new ReentrantLock();
    private Condition ikkeFull = l?s.newCondition();
    private Condition ikkeTom = l?s.newCondition();

    public void leggInn(String vare) throws InterruptedException {
        l?s.lock();

        try {
            while (varer.size() >= KAPASITET) {
                System.out.println("Romskipet er fullt. Leveringskip venter ...");
                ikkeFull.await();
            }
            varer.add(vare);
            System.out.println("Leveringsskipet leverte: " + vare);
            ikkeTom.signalAll();

        } finally {
            l?s.unlock();
        }
    }

    public String hentUt() throws InterruptedException {
        l?s.lock();
        try {
            while (varer.isEmpty()) {
                System.out.println("Romskipet er tomt. Astronaut venter ...");
                ikkeTom.await();
            }

            String vare = varer.remove(varer.size() - 1);
            System.out.println("Astronauten hentet: " + vare);
            ikkeFull.signalAll();
            return vare;
        } finally {
            l?s.unlock();
        }
        
    }
}