CompanyUsers

package AssociativeArraysExercise;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.*;

public class CompanyUsers {
    public static void main(String[] args) throws IOException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        String line = reader.readLine();
        Map<String, List<String>> companyNames = new TreeMap<>();

        while (!line.equals("end")){
            String[] input = line.split(" -> ");
            String company = input[0];
            String name = input[1];

            if (!companyNames.containsKey(company)){
                companyNames.put(company, new ArrayList<>());
                if (!companyNames.get(company).contains(name)){
                    companyNames.get(company).add(name);
                }

            }


            line = reader.readLine();
        }

        companyNames.entrySet().stream().sorted((e1, e2) -> {
            int x1 = e1.getValue().size();
            int x2 = e2.getValue().size();
            return Integer.compare(x1, x2);
        }).forEach(e -> {
            System.out.println(e.getKey());
            Collections.sort(e.getValue());
            for (String names : e.getValue()) {
                System.out.println("-- " + names);
            }
        });
    }
}