[NP] Container

import java.util.List;
import java.util.Scanner;
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;

public class Container<T extends Weightable> {

    List<T> elements;

    public Container() {
        this.elements= new ArrayList<>();
    }

    public double getTotalWeight(){
        return elements.stream().mapToDouble(i->i.getWeight()).sum();
    }

    public void addElement(T elem){
        elements.add(elem);
    }

    public List<T> lighterThan(T elem){
        return elements.stream().filter(i->i.getWeight()<elem.getWeight())
                .collect(Collectors.toList());
    }

    public List<T> between(T a, T b){
        return elements.stream().filter(i->i.getWeight()>a.getWeight()&&i.getWeight()<b.getWeight())
                .collect(Collectors.toList());
    }

    public boolean compare(Container<? extends Weightable> container){
        return this.getTotalWeight()>container.getTotalWeight();
    }


}
public interface Weightable<T> extends Comparable<Weightable<T>> {

    double getWeight();
}
public class WeightableString implements Weightable<WeightableString> {

    private String word;

    public WeightableString(String word) {
        this.word = word;
    }


    @Override
    public double getWeight(){
        return word.length();
    }


    @Override
    public int compareTo(Weightable o) {
        return (int)Double.compare(this.getWeight(),o.getWeight());
    }
}
public class WeightableDouble implements Weightable<WeightableDouble>{

    private double weight;

    public WeightableDouble(double weight) {
        this.weight = weight;
    }

    @Override
    public int compareTo(Weightable o) {
        return (int)Double.compare(this.getWeight(),o.getWeight());
    }

    @Override
    public double getWeight(){
        return weight;
    }

}

public class ContainerTest {
    public static void main(String[] args) {

        Container<WeightableDouble> container1 = new Container<>();
        Container<WeightableDouble> container2 = new Container<>();
        Container<WeightableString> container3 = new Container<>();
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();
        int p = sc.nextInt();
        double a = sc.nextDouble();
        double b = sc.nextDouble();
        WeightableDouble wa = new WeightableDouble(a);
        WeightableDouble wb = new WeightableDouble(b);

        for(int i=0;i<n;i++){
            double weight = sc.nextDouble();
            container1.addElement(new WeightableDouble(weight));
        }
        for(int i=0;i<m;i++){
            double weight = sc.nextDouble();
            container2.addElement(new WeightableDouble(weight));
        }
        for(int i=0;i<p;i++){
            String s = sc.next();
            container3.addElement(new WeightableString(s));
        }
        List<WeightableDouble> resultSmaller = container1.lighterThan(wa);
        List<WeightableDouble> resultBetween = container1.between(wa,wb);
        System.out.println("Lighter than "+wa.getWeight()+"!");
        for(WeightableDouble wd : resultSmaller){
            System.out.println(wd.getWeight());
        }
        System.out.println("Between "+wa.getWeight()+" and "+wb.getWeight()+"!");
        for(WeightableDouble wd : resultBetween){
            System.out.println(wd.getWeight());
        }
        System.out.println("Comparison: ");
        System.out.println(container1.compare(container2));
        System.out.println(container1.compare(container3));

    }
}