Hackerrank Java Instanceof keyword

[biryu2205]

import java.util.ArrayList;
import java.util.Scanner;

class Student {
}

class Rockstar {
}

class Hacker {
}

class InstanceOFTutorial {
  static String count(ArrayList mylist) {
    int a = 0, b = 0, c = 0;
    for (int i = 0; i < mylist.size(); i++) {
      Object element = mylist.get(i);
      if (element instanceof Student) {
        a++;
      }
      if (element instanceof Rockstar) {
        b++;
      }
      if (element instanceof Hacker) {
        c++;
      }
    }
    String ret = Integer.toString(a) + " " + Integer.toString(b) + " " + Integer.toString(c);
    return ret;
  }

  public static void main(String[] args) {
    ArrayList mylist = new ArrayList();
    Scanner sc = new Scanner(System.in);
    int t = sc.nextInt();
    for (int i = 0; i < t; i++) {
      String s = sc.next();
      if (s.equals("Student")) mylist.add(new Student());
      if (s.equals("Rockstar")) mylist.add(new Rockstar());
      if (s.equals("Hacker")) mylist.add(new Hacker());
    }
    System.out.println(count(mylist));
  }
}

[letientai299]

• Naming convention: wtf is a, b, c? What count really does?
• Use for-each instead of for
• InstanceOF...?