DSTG.java

//When I wrote this, only God and I understood what I was doing.
//Now, God only knows.
package dstg;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Scanner;
import java.util.function.Function;
import java.util.stream.Collectors;

@SuppressWarnings(value = "unchecked")
public class DSTG
{
    public static void main(final String[] args)
    {
        Scanner input = new Scanner(System.in);
        List<String> possibleFriends = new ArrayList<>();

        HashMap<String, List<String>> data = new HashMap<>();
        data.put("Filip", Arrays.asList("Ivan", "Marko", "Lucija", "Ana"));
        data.put("Mihovil", Arrays.asList("Marko", "Toni", "Karlo"));
        data.put("Iva", Arrays.asList("Marko", "Katarina"));
        data.put("Ivan", Arrays.asList("Filip", "Ana"));
        data.put("Marko", Arrays.asList("Filip", "Mihovil", "Iva", "Toni", "Katarina"));
        data.put("Toni", Arrays.asList("Mihovil", "Marko", "Lucija", "Katarina", "Karlo"));
        data.put("Lucija", Arrays.asList("Filip", "Toni", "Ana"));
        data.put("Katarina", Arrays.asList("Iva", "Marko", "Toni", "Karlo"));
        data.put("Karlo", Arrays.asList("Mihovil", "Toni", "Katarina"));
        data.put("Ana", Arrays.asList("Filip", "Ivan", "Lucija"));

        System.out.print("Ime osobe: ");
        String person = input.next();
        input.close();

        //trenutni prijatelji
        List<String> personFriends = data.get(person);
        for (String friend : personFriends)
        {
            //prolazi hashmapom
            Iterator it = data.entrySet().iterator();
            while (it.hasNext())
            {
                Map.Entry<String, List<String>> pair = (Entry<String, List<String>>) it.next();
                //postojeci prijatelj
                if (pair.getKey().toString().equals(friend))
                {
                    List<String> tempFriends = pair.getValue();
                    for (String tempFriend : tempFriends)
                    {
                        //provjerava je li tražena osoba ili je već među prijateljima
                        if (!tempFriend.equals(person) && !personFriends.contains(tempFriend))
                        {
                            possibleFriends.add(tempFriend);
                        }
                    }
                }
            }
        }

        //racunanje prioriteta
        Map<String, Long> friendPriority = possibleFriends.stream().collect(Collectors.groupingBy(Function.identity(), Collectors.counting()));
        //sortiranje
        Map<String, Long> finalMap = new LinkedHashMap<>();
        friendPriority.entrySet().stream().sorted(Map.Entry.<String, Long> comparingByValue().reversed()).forEachOrdered(e -> finalMap.put(e.getKey(), e.getValue()));

        System.out.println(System.lineSeparator() + "Mogući novi prijatelji:");
        finalMap.forEach((name, count) ->
        {
            System.out.println(name + ": " + count);
        });
    }
}