import java.util.LinkedList;

public class FruitBasket {
    private LinkedList<Fruit> fruits = new LinkedList<>();
    
    public void addFruit(Fruit f) {        
        fruits.add(f);
    }
    
    public LinkedList<Apple> getApples() {
        LinkedList<Apple> ret = new LinkedList<>();
        
        for (Fruit f : fruits)
            if (f.isApple())  // alternativ: f instanceof Apple
                ret.add((Apple) f);
        
        return ret;
    }
    
    public LinkedList<Fruit> getEqualOrLongerShelfLife(int n) {
        LinkedList<Fruit> ret = new LinkedList<>();
        
        for (Fruit f : fruits)
            if (f.shelfLife() >= n)
                ret.add(f);
        
        return ret;
    }
    
    public static void main(String[] args) {
        // Zum "Testen" (war nicht verlangt):
        FruitBasket s1 = new FruitBasket();
        s1.addFruit(new Apple());
        FruitBasket s2 = new FruitBasket();
        s1.addFruit(new Banana());
        s2.addFruit(new Apple());
        s1.addFruit(new Apple());
        s1.addFruit(new Pineapple());
        s1.addFruit(new GrannySmith());
        s1.addFruit(new PinkLady());
        s1.addFruit(new Banana());
        s1.addFruit(new PinkLady());
        
        for (Fruit f : s1.getApples())
            System.out.println(f);
    }
}