Ask HN: What % of your job interviewees pass FizzBuzz type questions? • Hacker News Board

Re: Ask HN: What % of your job interviewees pass FizzBuzz type questions?

#111

Post by elliottcarlson » Sat, Sep 17, 2011, 2:29 PM UTC

iron_ball wrote: post #90

elliottcarlson wrote: post #33

I have used various interview questions, including FizzBuzz, factorials and other questions, and I would say the success rate I saw was about 20%. My personal favorite question is to have someone write a shuffle function without using any built in randomization functions - however most people give up, and others can't follow simple directions and wrap their head around the problem. This particular question had more o…

Do you meant that they can't use Array.shuffle() or Array.sort( )? Or that they don't get any external source of randomness, even a 0.0 - 1.0 float?

No built in functions such as the ones mentioned, and preferably no quick entropy generating methods that are obvious but that's not as important as not using the built in functions. Another requirement is that each run of the function has to truly be a reshuffle of the array so that it can't be predictable.

It's harder than it sounds, but I also don't expect a perfect answer - generally I just want to see how people think out of thee box to try and solve an odd problem.

Re: Ask HN: What % of your job interviewees pass FizzBuzz type questions?

#112

Post by rmc » Sat, Sep 17, 2011, 3:19 PM UTC

ericb wrote: post #74

unshift wrote: post #73

Earlier quoted context omitted.

that question is a bit of a turn-off to me. obviously "benchmark it, see what's slowest, and make it faster" is a correct answer, and so is a 40 page essay about browser rendering, minification, full page caching, fragment caching, AJAX, etc. have you tried anything more specific?

If you have examples of more specific questions, I'm glad to hear them. I would accept either of your answers, btw. Answers I have seen include "It is always SQL" and "make it ajax--ajax is fast." The purpose is just to verify that they can put some ideas into writing, have a mental framework for debugging in place, and can verbally demonstrate any sort of familiarity with the technologies involved. It isn't a gotcha…

Answers I have seen include "It is always SQL" and "make it ajax--ajax is fast."

Haha, I see what you mean, that is a wordy FizzBuzz

Re: Ask HN: What % of your job interviewees pass FizzBuzz type questions?

#113

Post by petercooper » Sat, Sep 17, 2011, 10:54 PM UTC

Of those, about 50% can do FizzBuzz style questions. On paper, all of these ~10 people would be qualified to do the work

If it's for a programming position, the "paper" is lying in this case. If someone is claiming to have experience or qualification in certain areas that they can't even perform basic operations in, they're fraudsters.

It'd like trying to hire a surgeon and have someone turn up who doesn't even know what lymph nodes are. Dangerous and unhireable, but sadly a lot of employers put up with this sort of nonsense.

Re: Ask HN: What % of your job interviewees pass FizzBuzz type questions?

#114

Post by wavded » Sun, Sep 18, 2011, 1:46 AM UTC

I failed FizzBuzz, I admit it. I was asked that as an interview question. I studied hard for my interview but I forgot about the mod operator and totally fumbled my way through the interview. I am now the Senior Web Developer and turned out to be a great asset to the company. But you wouldn't have known that from my FizzBuzz results. I also didn't have 'Computer Science' as a Major. Couple strikes. However they took a chance on me.

Since then I've been able to interview others and I look for different things than FizzBuzz compliance. I want to see how they solve problems in general. I want to see if they have any passion for what they do. I want to see things they've developed.

Re: Ask HN: What % of your job interviewees pass FizzBuzz type questions?

#115

Post by ahi » Sun, Sep 18, 2011, 3:26 AM UTC

ericb wrote: post #74

unshift wrote: post #73

Earlier quoted context omitted.

that question is a bit of a turn-off to me. obviously "benchmark it, see what's slowest, and make it faster" is a correct answer, and so is a 40 page essay about browser rendering, minification, full page caching, fragment caching, AJAX, etc. have you tried anything more specific?

If you have examples of more specific questions, I'm glad to hear them. I would accept either of your answers, btw. Answers I have seen include "It is always SQL" and "make it ajax--ajax is fast." The purpose is just to verify that they can put some ideas into writing, have a mental framework for debugging in place, and can verbally demonstrate any sort of familiarity with the technologies involved. It isn't a gotcha…

To be fair, it almost always is SQL and ajax is a decent way to hide unavoidable performance problems when everything else fails. Point taken though.

Re: Ask HN: What % of your job interviewees pass FizzBuzz type questions?

#116

Post by jtchang » Sun, Sep 18, 2011, 7:23 PM UTC

aplusbi wrote: post #88

unshift wrote: post #75

Earlier quoted context omitted.

couldn't agree more. if i had to come up with a permutation algorithm as part of writing code, you'd better believe i'd look one up so that i'm sure i'm doing things optimally. i wouldn't trust myself to come up with the exactly right algorithm on the first try. if i had to deal with some weird half-sorted array, i assume i'd be working in the same context as the problem and wouldn't have to make up a solution on the…

These questions aren't about "real world" situations, they are about problem solving and basic coding. Questions are good, as is a discussion on how and why these things should be implemented. For the split array problem I rarely ask for code (only when I think it will actually help the candidate), it's just a discussion. It usually goes something like this: Candidate: Well I can sort it first, then do a binary searc…

My first intuition was that you could somehow write a binary search with two pointers throwing about half of the array away each time. I ran into issues with this train of thought because there might be duplicates in the array or the array might be all the same number.

My second thought was just do a linear search and if you happen to find the pivot, store it, and make the array sorted. Subsequent calls therefore would result in a binary search.

Re: Ask HN: What % of your job interviewees pass FizzBuzz type questions?

#117

Post by peteretep » Mon, Sep 19, 2011, 8:52 AM UTC

pixeloution wrote: post #32

spamizbad wrote: post #27

4 candidates, 2 passed FizzBuzz. Oddly, the two that failed had a Masters in CS (albeit no BS in CS). Of those that passed: one had Masters in Library Science looking to change careers. The other was a fresh out of college CS major from Illinois State. Next batch, I think we'll add another trivial question: count the number of vowels (a, e, i, o, u) in a string.

Am I hired? Or do I lose cool points for PHP?

You lose the cool points for not using a regex, I'm afraid.

Re: Ask HN: What % of your job interviewees pass FizzBuzz type questions?

#118

Post by joeycfan » Fri, Sep 23, 2011, 10:44 AM UTC

I got a lot of flack on reddit for posting this

(1..100).each{|i| outt = i.to_s outt = "Fizz" if i % 3 == 0 outt = "Buzz" if i % 5 == 0 outt = "FizzBuzz" if i % 5 == 0 and i % 3 == 0 puts outt }

The 'if i % 5 == 0 and i % 3 == 0' was especially criticised but I argued that it was transparently simple and easy to maintain.

Also - there's no need for clever opimizations in code this simple - and it's still order n code.

Re: Ask HN: What % of your job interviewees pass FizzBuzz type questions?

#119

Post by Someone » Wed, Sep 28, 2011, 7:15 AM UTC

pp13 wrote: post #81

eropple wrote: post #72

Earlier quoted context omitted.

I did not in any way, shape, or form claim that such questions determine whether or not a candidate is a good programmer. If you are going to respond to my posts, please respond to my posts and not what you think or wish I said in those posts. No interview or interview question can determine conclusively that you are a good programmer. But they reduce the likelihood that you're not, and comments like your strident an…

Ok, I didn't mean to offend you, I am sorry if I have. That being said these are my thoughts on the subject of interviewing programmers. When I just graduated college, I was all about puzzles and programming puzzles. My thoughts were that only people who could do these puzzles deserved programming jobs. I was so wrong. Puzzles are something that you get or don't get. If your in an interview, and you haven't faced tho…

"Another good permutation problem, is subset sum problem. [...] Is it possible to get better than O(n^2) for the optimal solution."

AFAIK subset sum is NP complete, so I guess you meant O(2^n). Even so, I would not expect a programmer to tell me much about it.

Re: Ask HN: What % of your job interviewees pass FizzBuzz type questions?

#120

Post by noahc » Wed, Sep 28, 2011, 8:36 PM UTC

pp13 wrote: post #64

noahc wrote: post #45

Earlier quoted context omitted.

1.8 Times?

1/2x +1/2(1/2x + 1/2(1/2x +1/2(1/2x + ... = y If x = 1, then the equation likes this: 1/2 +1/2(1/2 + 1/2(1/2 +1/2(1/2 + ... = y 1/2 +1/4 + 1/8 + 1/16 + 1/32 + ... = y y = 1 = x y = x source: http://library.thinkquest.org/J002235/hard.html u mad?

No, I am correct. When I was calculating the height of the paper, not the thickness.