Ask HN: Is asking obscure algorithms any test of programming ability? • Hacker News Board

Re: Ask HN: Is asking obscure algorithms any test of programming ability?

#41

Post by wapz » Thu, Apr 27, 2017, 5:24 AM UTC

murkle wrote: post #32

wapz wrote: post #27

I was recently asked to calculate the fibonacci sequence value in an O(log n) time complexity. I had no clue how to do it and explained that I can solve it in O(N) easily but don't even know how to approach the O(log n) method. I knew there must be some trick using factors but didn't even know how to start the problem. I looked it up later and one of the ways is using matrix multiplication (an implementation I still…

I wonder what the interviewer would have said if you'd written down Binet's formula :) http://mathworld.wolfram.com/BinetsFibonacciNumberFormula.ht...

Maybe his response would have been "Thank you for memorizing obscure formulas. Unfortunately, we look for motivated employees who study relevant topics pertinent to work."

Like really I don't know what to expect. I wonder what % of programmers can actually solve the problem without studying the solution (I'm sure there are many out there but I would guess most are from a mathematical field/background).

Re: Ask HN: Is asking obscure algorithms any test of programming ability?

#42

Post by 19eightyfour » Thu, Apr 27, 2017, 6:44 AM UTC

I recently did a test with a huge ( 200M MAU ) consumer company for a developer role ( back-end ), and the first test was extremely challenging. It wasn't algorithms per se, but maths. To solve this, you had to understand counting ( N choose K ) but to a level such that the way to solve these particular problems really only emerged in a paper a decade or so ago. So you had to go look up a paper, and implement. None of this was specified, I just had to figure it out. Another question also involved looking up a paper ( tho it probably could have been done another way as well ), and the easiest question was a relatively basic programming question. It was hard to see a rationale that linked the questions together, and linked the test to the role, but at least you could be sure that if people got through they were pretty clever and capable.

Re: Ask HN: Is asking obscure algorithms any test of programming ability?

#43

Post by bsvalley » Thu, Apr 27, 2017, 11:26 PM UTC

sigjuice wrote: post #40

bsvalley wrote: post #18

No it's stupid. Like asking an iOS engineer a question involving a tree data structure. It is stupid and irrelevant because at the end of the day our job is to build products/features. If you think at a student level you will never learn anything past college. Companies think that by default everyone can write code and build product. So they focus on stupid obscure stuff. I believe it's the opposite. We all went to c…

Will an iOS engineer never consider a binary search tree to store sorted data?

An iOS engineer would look at things like CoreData or Sqlite :) certainly not a binary search tree.