public class Search {
    public static void run() {

        Queue<String> q; 
        q = new LinkedQueue<String>();
        q.enqueue("");

        while (true) {
            String s;
            s = q.dequeue();

            q.enqueue(s + "0");
            q.enqueue(s + "1");

            System.out.println(q);
        }
    }
}