Writing a program with 2 threads which prints alternatively

Question

I got asked this question recently in an interview.

Write a program with two threads (A and B), where A prints 1 , B prints 2 and so on until 50 is r

Answer 1

This is another solution:

     Thread t1 = new Thread(new Runnable() {

        @Override
        public void run() {
            synchronized (lock) {
                for (int i = 1; i <= 50; i += 2) {
                    System.out.println("T1=" + i);

                    t1turn = false;
                        try {
                            lock.notifyAll();
                            lock.wait();
                        } catch (InterruptedException e) {
                        }
                }
            }

        }
    });
    Thread t2 = new Thread(new Runnable() {

        @Override
        public void run() {
            synchronized (lock) {
                for (int i = 2; i <= 50; i += 2) {
                    if (t1turn)
                        try {
                            lock.wait();
                        } catch (InterruptedException e) {
                        }
                    System.out.println("T2=" + i);
                    t1turn = true;
                    lock.notify();
                }
            }
        }
    });
    t1.start();
    t2.start();