4, Logs Aggregator

import java.util.Map;
import java.util.Scanner;
import java.util.TreeMap;
import java.util.TreeSet;


public class _04_Problem4 {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int number = Integer.parseInt(sc.nextLine());

        Map<String, User> users = new TreeMap<>();

        for (int i = 0; i < number; i++) {
            String[]  line = sc.nextLine().split(" ");


            if(users.containsKey(line[1])) {
                users.get(line[1]).addIP(line[0]);
                users.get(line[1]).addDuration(Long.parseLong(line[2]));
                users.put(line[1], users.get(line[1]));
            }
            else {
                users.put(line[1], new User(line[1], line[0], Long.parseLong(line[2])));
            }


        }

        for (Map.Entry<String, User> user : users.entrySet()) {
            System.out.println(user.getValue().toString());
        }


    }

}


class User {
    private String name;
    private TreeSet<String> IP;
    private long duration;

    public User() {
        IP = new TreeSet<>();
    }

    public User(String name, String ip, long duration) {
        this.IP = new TreeSet<>();
        this.name = name;
        this.IP.add(ip);
        this.duration = duration;
    }

    public void addIP(String ip) {
        this.IP.add(ip);
    }
    public void addDuration(long dur) {
        this.duration += dur;
    }

    public String toString() {
        String allIP = "";

            allIP = this.IP.toString();


        return this.name + ": " + this.duration + " " + allIP;//+ this.duration + " [" + allIP + " ]";
    }

}