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Quixey Challenge: $100 for a 1-Minute Coding Puzzle

blog.quixey.com

21–30 of 34 posts

Re: Quixey Challenge: $100 for a 1-Minute Coding Puzzle

#25
post #20

Earlier quoted context omitted.

This challenge has almost nothing to do with Python. That's absolutely not true once you add the time limit. As someone that never touches Python if I don't have to, I'd immediately get derailed for a few seconds (5?) guessing what arr[1:] means, then waste some time worrying about whether "if not arr" properly handles whatever it is that the awkward looking filter-without-using-the-word-filter clause spits back (doe…

I disagree. The failure to consider the case where the target value is equal to the pivot is one of the classic blunders of writing a quicksort (along with not considering type limits and getting involved in a land war in Asia). Almost so much so that I immediately thought that I could have made a pretty good guess at the bug if they had told me the algorithm beforehand :-) You could look at the code and try and figu…

classic blunders of writing a quicksort

Actually the classic blunder of writing a quicksort would be writing a quicksort. It's not something you'd normally do in a real code-base.

Likewise the classic blunder of these puzzle-tests is that they don't select for the skills that you need to fix real bugs. My first stab at debugging a sort-function would be to write a unit-test. Wonder if any of the candidates did that in the 60 seconds that they were given...

Re: Quixey Challenge: $100 for a 1-Minute Coding Puzzle

#26
I'm a first year college student, and I relied on my Java experience and the 3 times I've seen Python code to get me through it. Unfortunately, sorting algorithms were the one thing I didn't pay much attention to, so I was clueless. However, I feel that with a little bit of background knowledge, the problem would be relatively easy.

Re: Quixey Challenge: $100 for a 1-Minute Coding Puzzle

#27
post #24

Be prepared to wait in a queue for a couple hours

Another datum: I sent an IM at 2pm PST and haven't received any response yet. (Looks like quixeychallenge offline the whole time)

It would have been fun to take part but I think the poor guys are swamped.

Re: Quixey Challenge: $100 for a 1-Minute Coding Puzzle

#28

  "  Extraordinary software engineering talent.
    Have written 50,000 good-looking lines of code.
    Before that, have written 50,000 lines of code that you're embarrassed by.
    Know all that stuff they teach in college CS that most people forget.
    Speak and write clear arguments, explanations and proofs.
    Can write a compiler from scratch.
    Can write a quine.
    Can write binary search with no off-by-one errors in under 2 minutes.
" getting tired by these requirements

Re: Quixey Challenge: $100 for a 1-Minute Coding Puzzle

#29

Tried it, but failed. Alas. That said, it was very enlightening to me just how anxious I was! There is really no downside whatsoever to the challenge, and the possibility of a quick $100, yet I was still questioning whether I should do it. So, I encourage you, do it! Failing is not that bad. :-p

I agree. It was thanks to your comment that I tried the challenge. I didn’t win, but the challenge was totally fair and I feel like I could have won had I been more familiar with algorithms. Even though I failed, I did get a quick refresher on the algorithm in question and learned a new Python standard library function. So next time this kind of opportunity appears, people, try it! (I say next time because I think the Quixey Challenge is about to end.)

Re: Quixey Challenge: $100 for a 1-Minute Coding Puzzle

#30
post #25
post #20

Earlier quoted context omitted.

I disagree. The failure to consider the case where the target value is equal to the pivot is one of the classic blunders of writing a quicksort (along with not considering type limits and getting involved in a land war in Asia). Almost so much so that I immediately thought that I could have made a pretty good guess at the bug if they had told me the algorithm beforehand :-) You could look at the code and try and figu…

classic blunders of writing a quicksort Actually the classic blunder of writing a quicksort would be writing a quicksort. It's not something you'd normally do in a real code-base. Likewise the classic blunder of these puzzle-tests is that they don't select for the skills that you need to fix real bugs. My first stab at debugging a sort-function would be to write a unit-test. Wonder if any of the candidates did that i…

> My first stab at debugging a sort-function would be to write a unit-test.

I applaud your discipline, but I can't help but feel like you're punting at writing code when you say things like this.

And the real problem is that unit tests only reflect your expectations. Unless you're familiar with quicksort, you probably won't know what kind of test to write. You'd have to write a very specific dataset: sort(A) ∃ x: A[x] = A[0]. You're probably not using Quickcheck, and the odds of thinking of writing that specific case are slim.

You have to look at the code to get a sense of where the testable edges should be. And in doing so, you should instantly spot this bug. Anyone who can't see it within 60 seconds would be an instant no hire for any but the most junior positions (if I had any say about it, anyways). Even if they don't know Python, they were told there was a bug.

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