Comments on: From interviewee to interviewer in seven months

By: A better solution to the FizzBuzz interview problem | Cyde Weys Musings

A better solution to the FizzBuzz interview problem | Cyde Weys Musings — Wed, 02 Jul 2008 22:33:12 +0000

[...] months ago, I wrote about a simple programming problem that I was administering to interviewees at work to assess their programming skills. The basic problem is this: loop through a range of integers, [...]

By: Cyde Weys

Cyde Weys — Thu, 26 Jun 2008 15:07:25 +0000

Well I would typically start the question by making sure they knew what the Fibonacci sequence was. It’s really easy though. F(1)=F(2)=1, for all n>2: F(n)=F(n-1)+F(n-2)

By: William (green)

William (green) — Thu, 26 Jun 2008 07:39:13 +0000

I’d have to do research to know how to calculate any numbers in a Fibonacci sequence, ’cause I don’t remember what they are exactly. Whereas Fizzbuzz is just simple programming, and fairly easily done.

By: Cyde Weys

Cyde Weys — Wed, 25 Jun 2008 23:48:36 +0000

I didn’t go that route because it made the code messier, requiring keeping track of more state. I didn’t say that my code was optimal, only that it was more efficient than his (three divides versus four divides). So no, I don’t suck. Here’s an off-the-top-of-my-head approach at two divides (omitting the for-loop as it’s not relevant):

bool flag = false; if (i % 3 == 0) { flag = true; print "Fizz"; } if (i % 5 == 0) { flag = true; print "Buzz"; } if (!flag) { print i; } print "\n";

I do think if I ever ask prospective interviewees this question again, I’ll ask them to optimize it down to two divides just to make sure they know how to do it. And if I’m really feeling evil, I’ll also ask them how to do it without defining an additional state variable (hint: think gotos).

By: Kelly Martin

Kelly Martin — Wed, 25 Jun 2008 21:54:06 +0000

Checking for mod 15 more efficient? How in the hell do you figure that? You’re doing three integer divides, which are pretty expensive instructions. If you check for 3 and 5 separately, you only use two integer divides.

I don’t want either one of you writing code for imbedded systems, video codecs, or anything else where cycles really matter. You both suck.

By: Cyde Weys

Cyde Weys — Wed, 25 Jun 2008 16:07:33 +0000

Dear God, that's so much whitespace. Allow me to Perl one-line it, if you will:

for (int i = 0; i <= 100; i++) { if (i % 15 == 0) { print "FizzBuzz"; } elsif (i % 3 == 0) { print "Fizz"; } elsif (i % 5 == 0) { print "Buzz"; } else { print "$i"; } print "\n"; }

Everyone seems to check mod 3 and mod 5 individually, not realizing that checking for mod 15 is equivalent and more efficient. I haven't yet seen one person implement it using mod 15. More recently I've just taken to asking people to write a recursive function that calculates the nth Fibonacci number. That's a good weed-out question. (I should point out that your solution is slightly incorrect because you don't print out anything for 100, which is in the inclusive range.)

By: Tawker

Tawker — Wed, 25 Jun 2008 06:29:12 +0000

Err I made a typo

add if(i%5 ==0 && i%3 == 0)
{
System.out.println(“FizzBuzz”);
} as the first if and else if on the rest

By: Tawker

Tawker — Wed, 25 Jun 2008 06:08:57 +0000

public class FizBuzz{

public static void main(String[] args) {

// Write a program that prints the numbers from 1 to 100.
// But for multiples of three print “Fizz” instead of the number and
// for the multiples of five print “Buzz”.
// For numbers which are multiples of both three and five print “FizzBuzz”

for (int i = 1; i< 100; i++)
{
if(i%3 == 0)
{
System.out.println(“Fizz”);
}
else if(i%5 ==0)
{
System.out.println(“Buzz”);
}
else
{
System.out.println(i);
}
}
}

}

Actual time needed, 1 minute.

By: The hallmarks of a good programmer | Cyde Weys Musings

The hallmarks of a good programmer | Cyde Weys Musings — Fri, 07 Mar 2008 23:15:08 +0000

[...] qualifications, gives me a good idea for what types of questions I should be asking when I do more potential employee interviews. I’ve already subconsciously realized that one of the aspects that makes me a good programmer [...]

By: William

William — Sun, 11 Nov 2007 09:22:29 +0000

Huh, I thought it was just my imagination. I’ve noticed that many of the students in my CS classes are totally stumped by even basic programming problems and fail to apply any sort of basic programming theory. Saw a guy make a true/false array instead of an int. And instead of making an actual array object, he made 18 different boolean values, one for each possible. I can understand that sort of thing from one guy, once in a while, ’cause he wasn’t thinking. But this sort of thing seems to be done by half the class for some of the assignments.
I’m trying to avoid this trap, myself, but I’m not having much luck. I realize the whole idea is basically to grab a book and go through it, grab a new one, rinse, repeat, but…
Well, good luck on having a pleasant interview. I’m curious to see your, for want of a better phrase, after action report.

By: Kelly Martin

Kelly Martin — Fri, 09 Nov 2007 13:17:28 +0000

I once interviewed candidates for a systems administration position that would include Microsoft Exchange administration. My “stumper” question was “Can you tell me one of the differences between Exchange Standard Edition and Exchange Enterprise Edition?” I, myself, had only encountered this a few days previously (we were running Standard, and had recently exceeded the total store size limit, which at that time was 16GB).

I didn’t expect candidates to know the answer. (It’s easy enough to find out in practice by going to the Microsoft Exchange product website.) I was more interested in seeing how candidates reacted to being asked this question. I had one (who we did not select) whose response was basically “I’m an MCSE, I should know this!” repeated over and over again. He spent the rest of the interview obsessing over this, apologizing almost continuously for his lack of knowledge.