On Hiring and FizzBuzz | Hacker News Reader

On Hiring and FizzBuzz

topherlandry.wordpress.com

4 pointsscrabble8 comments

I honestly don't know if it's the mathematician in me, or if I'm just a cranky person, or if I actually have a valid point, but if I were given the FizzBuzz task the way it is worded here, I would reject it on the grounds that it is self-contradictory:

'for multiples of three print “Fizz” instead of the number [...]. For numbers which are multiples of both three and five print “FizzBuzz”'

So for the number 15, for example, I am being asked to print "Fizz" instead of the number, but I am also asked to print "FizzBuzz". That cannot be done. A valid way of formulating the problem would be:

Write a program that prints the numbers from 1 to 100. But for multiples of three that are not multiples of five print “Fizz” instead of the number, and for multiples of five that are not multiples of three print “Buzz” instead of the number. For numbers which are multiples of both three and five print “FizzBuzz” instead of the number.

An alternate way of saying it would be:

Write a program that prints the numbers from 1 to 100, except for numbers that are multiples of three or five. For multiples of three print “Fizz”. For multiples of five print “Buzz”.

(Edit: no, the above doesn't work, because it would allow you to print "BuzzFizz" for numbers like 15. You'd still have to add, 'For numbers which are multiples of both three and five, print “FizzBuzz”.' So it's really just the clause "instead of the number" in the original formulation that causes the contradiction.)

It's still a good test. I wouldn't hire you if you insist on making a problem out of something you understand perfectly well.

I'm in the camp who thinks that fizzbuzz is a "do you know the modulus operator?" test.

I use the modulus operator several times a week but I realize that the software world is a pretty big place and people do not all know the same things that I do because they don't have any reason to.

For example: I never have cause to use a hash table. It's not something applicable to the stuff I work on. A world where hash tables aren't useful is probably unimaginable to some of you. I can assure you, I'm not an idiot - my mother had me tested ;-) I just work in a different corner of the programming space than the mainstream developer.

FWIW, Trello's FizzBuzz has more meat to it than this article suggests :-)

It really is an excellent FizzBuzz, and I feel like it gets to the root of what FizzBuzz should be accomplishing -- does someone understand basic programming constructs like loops, and are they able to analyze and solve the problem?

The people that I've shown it to in person tend to overthink it on first go, going so far as to talk about rainbow tables to solve the hash. In fact, if you spend the time to look at the hashing algorithm itself it's much easier (and is also a terrible "hash.")

You can even implement FizzBuzz without being aware of the modulo operator. It's not that hard to write your own test that does the same thing.

Sure you could have two counters, one initialized to 3 and one to 5, that are decremented each time thru the loop. When they reach zero print Fizz or Buzz and reinitialize.

Or you could create a finite list, initialize each member to its index, then go through by 3's and 5's and replace a number with Fizz or Buzz, or if not a number just add it.

Or you could create a program that generates print statements that print the same, then run that.

Or you could write a scraper that searches the web for 'fizzbuzz solution' and print the text on that page.

Or...

Or you take the number, divide it by 3, round down, multiply by 3, and if it's the same as the original, you print Fizz. Same effect as the modulo operator, but without the modulo operator.

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