Java puzzle 1

Hi Guys,

While going through some websites, I have found this interesting java puzzle and thought of sharing it with you!! J

Problem: You have to print “I am added 30 Students to a LKGClass of strength 10!!” by running the Tester class.

Restrictions: You are not allowed to modify the LKGClass but allowed to modify the Tester class. You are allowed to use any java programming tactics.

public class Student{

}

import java.util.HashSet;

import java.util.Set;

public class LKGStudent{

private static final int STRENGTH=10;

private Set< Student > student=new HashSet< Student >();

public synchronized void addStudent(Student s){

                if(student.size()==STRENGTH){

                                throw new IllegalStateException("I'm full");

    }

                else{

                student.add(s);

                }

}

public synchronized void solvedPuzzle(){

                if(student.size()==30){

                //The goal of this puzzle is to reach this line!

                System.out.println("I am added 30 Students to a LKGClass of strength 10!!");

                }             

}

}

public class Tester{

//This tester is a starting point and doesn’t print "I am added 30 Students to a LKGClass of strength 10!!" //try by modifying this class!!

public static void main(String [] args){

LKGStudent lkg=new LKGStudent();

for(int i=0;i<20;i++){

                lkg.addStudent(new Student());

}

lkg.solvedPuzzle();

}

}

Hope this Helps!!