Java Interview Puzzler

hashbrown — Thu, 18 Jun 2009 23:34:30 +0000

This is a puzzler we created at my work to use as an interview problem. I had a fun time taking it myself, and got it wrong the first time! It was designed to mimic some bad legacy code you might encounter when working on a large aging system, that has passed through many hands. Terrible coding practices, no javadocs or comments, etc. You are tasked to figure out what the heck it does.
First – does it compile? If not, how do you fix it?
Second – If it compiles, what is the output?

I’ll answer questions and post the solution in the comments.

package crazy;

public class Timing extends R {
    public static final Integer t = new Integer("4");

    public static void main(String[] args) {
        Timing t = new Timing(11);

        System.out.print(t.foo);
        bat(t);
    }

    void fob() { fod(); }

    public Timing(int value) {

        super();
        foo = foo % value;
        bar();
    }

    static {
        System.out.print("6");

    }

    private void bar() {
        new Baz().bar(5);
        tr = "2";
    }

    private int foo = 25;

    static void r() { System.out.println("1"); }
}

abstract class R {

    String tr = "9";

    static void bat(R r) {
        r.fob();
        System.out.print(r.tr);

    }

    private int negate(int bam) {
        return bam * -1;
    }

    public R() {
        System.out.print("7");
    }

    void fod() { System.out.print((int)Math.floor(.99)); }

    protected final int t() {
        return 5;
    }

    class Baz {

        void bar(int fob) {
            if (fob == 9)
                System.out.print(String.valueOf(fob++));

                System.out.print(String.valueOf(negate(fob++)));
            if (fob == 5)
                System.out.print(String.valueOf(fob+=2));

        }
    }

    static {
        System.out.print("8");
    }

    abstract void fob();

}

Hashbrown on the Mic » puzzler

Java Interview Puzzler