НЛ Лаб6 Зад1

import java.util.*;


class App{
    private String ime, opis;
    private int ocenka;
    private double cena;

    public App(String ime, String opis, int ocenka, double cena){
        this.ime=  ime;
        this.opis = opis;
        this.cena = cena;
        this.ocenka = ocenka;
    }

    public String getName() {
        return ime;
    }

    public String getOpis() {
        return opis;
    }

    public double getPrice() {
        return cena;
    }

    public int getRating() {
        return ocenka;
    }


}

class AppManager{
    private LinkedList<App> apps;
    private LinkedList<Integer> random;
    int iskoristeno;

    public AppManager(App[] niza){
        apps = new LinkedList<App>();
        random = new LinkedList<Integer>();
        for(int i=0;i<niza.length;i++){
            apps.add(niza[i]);
            random.add(0);
        }
        iskoristeno = 0;

    }

    public App bestApp(){
        App tmp = apps.get(0);
        for(int i=1;i<apps.size();i++){
            if(apps.get(i).getRating()>tmp.getRating()){
                tmp = apps.get(i);
            }
        }
        return tmp;
    }

    public App cheapestApp(){
        App tmp = apps.get(0);
        for(int i=1;i<apps.size();i++){
            if(apps.get(i).getPrice()<tmp.getPrice()){
                tmp = apps.get(i);
            }
        }
        return tmp;
    }

    public int[] ratingStats(){
        int[] ratings = new int[5];
        for(int i=0;i<5;i++) ratings[i] = 0;
        for(int i=0;i<apps.size();i++){
            ratings[apps.get(i).getRating()-1]++;
        }
        return ratings;
    }

    public List<App> allApps(String attribute, boolean ascending){
        LinkedList<App> lista = new LinkedList<App>();
        for(App ap : apps){
            lista.add(ap);
        }

        if(attribute.equals("name")){
            Collections.sort(lista, new NameComparator());
        }
        else if(attribute.equals("price")){
            Collections.sort(lista, new PriceComparator());
        }
        else if(attribute.equals("rating")){
            Collections.sort(lista, new RatingComparator());
        }
        else return null;

        if(!ascending){
            Collections.reverse(lista);
        }
        return lista;
    }

    public List<App> randomChoice(){
        LinkedList<App> lista = new LinkedList<App>();
        Random randomGenerator = new Random();
        int brojac = 0;
        if(iskoristeno==apps.size()){
            for(int i=0;i<apps.size();i++){
                random.set(i, 0);
            }
            iskoristeno = 0;
        }
        while(iskoristeno<apps.size()){
            if(brojac==3) break;
            int randomInt = randomGenerator.nextInt(apps.size());

            if(random.get(randomInt)==0){
                lista.add(apps.get(randomInt));
                random.set(randomInt, 1);
                brojac++;
                iskoristeno++;
            }

        }
        return lista;
    }


}

class NameComparator implements Comparator<App> {
    @Override
    public int compare(App a1 , App a2){
        return a1.getName().compareTo(a2.getName());
    }
}

class PriceComparator implements Comparator<App> {
    @Override
    public int compare(App a1 , App a2){
        double rez = a1.getPrice()-a2.getPrice();
        if(rez<0) return -1;
        if(rez>0) return 1;
        return 0;
    }
}

class RatingComparator implements Comparator<App> {
    @Override
    public int compare(App a1 , App a2){
        return a1.getRating()-a2.getRating();
    }
}

public class AppManagerTest {

    public static void main(String[] args) throws Exception {
        Scanner jin = new Scanner(System.in);
        int n = Integer.parseInt(jin.nextLine());
        App[] apps = new App[n];
        for ( int i = 0 ; i < n ; ++i ) {
            apps[i] = new App(jin.nextLine(),jin.nextLine(),jin.nextInt(),jin.nextDouble());
            jin.nextLine();
        }
        int k = jin.nextInt();
        AppManager am = new AppManager(apps);
        if ( k == 0 ) { //test everything but randomChoice
            while ( true ) {
                System.out.println();
                String cmd = jin.next();
                System.out.println(cmd);
                if ( cmd.equals("stop") ) break;
                if ( cmd.equals("bestApp") ) {
                    print(am.bestApp());
                }
                if ( cmd.equals("cheapestApp") ) {
                    print(am.cheapestApp());
                }
                if ( cmd.equals("allApps") ) {
                    print(am.allApps(jin.next(),jin.nextBoolean()));
                }
                if ( cmd.equals("ratingStats") ) {
                    System.out.println(Arrays.toString(am.ratingStats()));
                }
            }
        }
        else { //test randomChoice
            System.out.println("Testing random choice...");
            int w = jin.nextInt();
            for ( int q = 0 ; q < w ; ++q ) {
                boolean[] flags = new boolean[n];
                for ( int i = 0 ; i <= n/3 ; ++i ) {
                    List<App> res = am.randomChoice();
                    for ( App a : res ) {
                        int idx = idxOf(apps,a);
                        if ( idx == -1 ) System.out.println("You returned an app that wasn't in the list at all? What are you doing???");
                        if ( flags[idx] ) {
                            System.out.println("You returned an app twice, before returning all the apps in the list. I want to see all the apps first then you can give me duplicates.");
                            throw new Exception("App already returned");
                        }
                        flags[idx] = true;
                    }
                }
            }
            System.out.println("Great work on implementing randomChoice. That is just what we needed.");
        }
    }

    private static void print(App app) {
        System.out.println("Name: "+app.getName());
        System.out.println("Rating: "+app.getRating());
        System.out.printf("Price: %.2f$\n",app.getPrice());
    }

    private static void print(List<App> apps) {
        for ( App ap : apps ) {
            print(ap);
            System.out.println();
        }
    }

    private static int idxOf(App apps[],App a){
        for ( int i = 0 ; i < apps.length ; ++i )
            if ( equal(apps[i],a) ) return i;
        return -1;
    }

    private static boolean equal(App a , App b) {
        return a.getName().equals(b.getName())&&a.getPrice()==b.getPrice()&&a.getRating()==b.getRating();
    }

}