Programmers can’t write algorithms without help • Hacker News Board

Re: Programmers can’t write algorithms without help

#11

Post by starbugs » Mon, Nov 04, 2019, 4:36 PM UTC

Sarki wrote: post #10

starbugs wrote: post #2

> Programmers can’t write algorithms without help And that might be a good thing. How often does a normal software engineer have to write bubble sort from scratch in his daily life? If someone from my team came to me telling me he had to sort an array and wrote bubble sort from scratch, then I'd probably not be very happy with that unless there is a really good reason to spend that time on it rather than using an exi…

I agree, what's more important IMHO is education/knowledge of existing data manipulation, after all 99% of the work is reuse not pure creation (incremental vs pure innovation). Algorithmicians (? - well... algorithm researchers, obviously) and programmers are not working in the same field of work, even though the boundary might seem thin for most, there's a world between both. Must all painters be artists?

I would go as far as saying that an "artist" might be detrimental to reaching your goal in a lot of cases, especially if a team is involved.

Re: Programmers can’t write algorithms without help

#12

Post by delinquentme » Mon, Nov 04, 2019, 4:36 PM UTC

commandlinefan wrote: post #8

Whenever this comes up, I can only assume that people are talking about very different sorts of technical interviews than I’ve ever been subject to. I’ve been working as a programmer for 25 years now and must have been through at least two dozen technical interviews in that time (one just a couple of years ago) and I’ve never had this level of pedantry thrown at me. It sounds like the poster has been rejected from a…

Yes you're the exception.

Somehow we arent really adept at interviewing at what the day-to-day requirements of a position.

Instead were much more interested in edge-case stuff like bubble sort.

I wonder if this is some assessment of "are they capable of substantially more complex tasks, and if so, safe to assume they're capable of less-complex minutiae.

Seems about right, as often these evaluation type things are proxies.

Re: Programmers can’t write algorithms without help

#13

Post by dickeytk » Mon, Nov 04, 2019, 4:39 PM UTC

starbugs wrote: post #2

> Programmers can’t write algorithms without help And that might be a good thing. How often does a normal software engineer have to write bubble sort from scratch in his daily life? If someone from my team came to me telling me he had to sort an array and wrote bubble sort from scratch, then I'd probably not be very happy with that unless there is a really good reason to spend that time on it rather than using an exi…

I get your point, but why would you pick bubble sort?

That’s one any engineer should be able to implement without any help. It’s the more complex/useful ones worth discussing.

Even Obama knows this: https://m.youtube.com/watch?v=k4RRi_ntQc8

Re: Programmers can’t write algorithms without help

#14

Post by starbugs » Mon, Nov 04, 2019, 4:42 PM UTC

dickeytk wrote: post #13

starbugs wrote: post #2

> Programmers can’t write algorithms without help And that might be a good thing. How often does a normal software engineer have to write bubble sort from scratch in his daily life? If someone from my team came to me telling me he had to sort an array and wrote bubble sort from scratch, then I'd probably not be very happy with that unless there is a really good reason to spend that time on it rather than using an exi…

I get your point, but why would you pick bubble sort? That’s one any engineer should be able to implement without any help. It’s the more complex/useful ones worth discussing. Even Obama knows this: https://m.youtube.com/watch?v=k4RRi_ntQc8

I picked bubble sort, because it's literally the example from the first sentence of the article:

> David Hansson, the creator of Ruby on Rails, admitted in a tweet that he wouldn’t be able to write bubble sort on a whiteboard.

Re: Programmers can’t write algorithms without help

#15

Post by 99052882514569 » Mon, Nov 04, 2019, 4:43 PM UTC

glitchc wrote: post #6

Yet another article showcasing how the tech interview process is fundamentally flawed. Personal anecdote: I recently underwent an interview process for a position in my field of expertise (computer vision) consisting of multiple in-person stages, whiteboard coding, product design and a take-home assignment that required developing a foundational (bubble-sort like) algorithm from scratch. After successfully completing…

This is infuriatingly stupid. Not only does that waste your time (which we can be uncharitable and say they don't care about), but it wastes their time! i.e. costs lots and lots of money.

Re: Programmers can’t write algorithms without help

#16

Post by nraynaud » Mon, Nov 04, 2019, 4:43 PM UTC

starbugs wrote: post #2

> Programmers can’t write algorithms without help And that might be a good thing. How often does a normal software engineer have to write bubble sort from scratch in his daily life? If someone from my team came to me telling me he had to sort an array and wrote bubble sort from scratch, then I'd probably not be very happy with that unless there is a really good reason to spend that time on it rather than using an exi…

And also, even if the sort was important in my app and there was a superior compelling reason to rewrite it internally (one common case is computing 2 things at once), I would probably google what people in the domain do and think first, try to find a few blog post from people who implemented a sort to look at tradeoffs (getting a feel for the politics is in the domain: they probably critiqued each other's "real life" loads, optimization goal: memory vs. CPU vs cache), and then find something on github that I can follow, and do my tweak on.

Re: Programmers can’t write algorithms without help

#17

Post by oneplane » Mon, Nov 04, 2019, 4:43 PM UTC

glitchc wrote: post #6

Yet another article showcasing how the tech interview process is fundamentally flawed. Personal anecdote: I recently underwent an interview process for a position in my field of expertise (computer vision) consisting of multiple in-person stages, whiteboard coding, product design and a take-home assignment that required developing a foundational (bubble-sort like) algorithm from scratch. After successfully completing…

It's very weird how some of those tech interviews are done. I've luckily never had to do one of those, but from the YouTube videos of training interviews and example interviews, almost everyone seems to be asked to implement a slight variation on something to be found in a Data Structures & Problem Solving book by Weiss. Great if that is what you'll be doing all day, but regurgitating some way to get the smallest number in a list or making a directed graph for a word morphing joke hardly represents anything other than a persons skill to repeat what someone else did and wrote down decades ago.

Re: Programmers can’t write algorithms without help

#18

Post by dragontamer » Mon, Nov 04, 2019, 4:44 PM UTC

starbugs wrote: post #14

dickeytk wrote: post #13

Earlier quoted context omitted.

I get your point, but why would you pick bubble sort? That’s one any engineer should be able to implement without any help. It’s the more complex/useful ones worth discussing. Even Obama knows this: https://m.youtube.com/watch?v=k4RRi_ntQc8

I picked bubble sort, because it's literally the example from the first sentence of the article: > David Hansson, the creator of Ruby on Rails, admitted in a tweet that he wouldn’t be able to write bubble sort on a whiteboard.

I wouldn't be able to write a bubble-sort specifically.

But if I were asked to "sort" a set of numbers, I'm sure I'd come up with some unholy combination of bubble, selection, and insertion sort that got the job done.

I always have to consult the books to remember the difference between bubble, insertion, and selection sorts. But even without documentation, surely people can write a list of numbers (ex: 9, 4, 5, 3, 2, 6, 0, 1, 8, 7), and then tinker with an algorithm until that list was in order? (0 1 2 3 4 5 6 7 8 9)

------------

Here's the thing about programming: you don't have to travel very far before you get into the "nobody knows the answer". The internet provides enough information for the first ~2 months on the job. Specialized books on your topic (ex: GPUs, HPC, OpenMP, etc. etc.) may cover another 1 or 2 months of training on the job.

After that? Nobody in the world is doing what you do. Nobody has to work with your particular configuration of tools, your particular problems (performance? Bugs? Architecture?). Your particular office politics. Literally no one else in the world. And yet, you'll be responsible for coming up with a solution that works, even without any guides.

That's why people like testing people "without the internet". Because in most cases, there's no guide to tell you how to progress a real project in the real world.

Re: Programmers can’t write algorithms without help

#19

Post by kiba » Mon, Nov 04, 2019, 4:44 PM UTC

stunt wrote: post #4

String length in Python is maybe too much exaggeration unless someone hasn’t wrote Python for a long time. But, algorithms? Sure! Nobody remembers them for ever. Often you at least need to read how the algorithm works before implementing it. Obviously for most devs it is faster to just search for a sample implementation or a pseudocode.

You can store those information inside a SRS system which lets you remember those algorithms essentially forever.

Re: Programmers can’t write algorithms without help

#20

Post by oneplane » Mon, Nov 04, 2019, 4:45 PM UTC

99052882514569 wrote: post #15

glitchc wrote: post #6

Yet another article showcasing how the tech interview process is fundamentally flawed. Personal anecdote: I recently underwent an interview process for a position in my field of expertise (computer vision) consisting of multiple in-person stages, whiteboard coding, product design and a take-home assignment that required developing a foundational (bubble-sort like) algorithm from scratch. After successfully completing…

This is infuriatingly stupid. Not only does that waste your time (which we can be uncharitable and say they don't care about), but it wastes their time! i.e. costs lots and lots of money.

I'd say give them a doubly-linked list for their doubly-stupid hiring process.