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A comment on Google Tech Dev Guide. Parent comment

Re:Google Tech Dev Guide by m0zg on Tuesday December 18, 2018 @10:35PM (#18712812)
The problem here is the only non-bruteforce solution worth pursuing here involves DP with less-than-straightforward memoization rules, which the engineer is unlikely to actually use before or after the interview. So she has to waste a month studying _specifically for the interview_ and "refreshing" the skills she won't actually need on the job. It's like you're hiring a welder, but you want them to be good at juggling as well, just for the interview.

Don't get me wrong, I'm not saying DP is useless, it came in handy a couple of times over the course of my 20+ year career. I'm just saying that you could always look it up, and the amount of signal you get out of someone solving this problem is very close to zero, because it amounts to: "this person solved this problem before the interview", whereas the question you really need to answer is "can this person solve the problems we need solved".

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Re:Google Tech Dev Guide by kagol on Tuesday December 18, 2018 @11:11PM (#18712950)
> The problem here is the only non-bruteforce solution worth pursuing here involves DP with less-than-straightforward memoization rules

The solution commentary [1] doesn't mention DP.

[1]: https://techdevguide.withgoogle.com/resources/find-longest-w...

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Re:Google Tech Dev Guide by SamReidHughes on Tuesday December 18, 2018 @11:40PM (#18713052)
Actually looking at their "brute force" solution, what I was referring to as brute force was their "greedy" algorithm, and the first optimization I came up with was the most optimal solution. I'd call that a very natural strategy to take -- try doing the words simultaneously instead of separately, and you see it.

I don't even see that as DP.

Not everybody will be as quick as me, but there are plenty of people that don't spend a month practicing for a Google interview. If somebody is practicing solving data structures problems for the first time in their life, that's fine -- maybe they went to a substandard school. But if they have to spend a month refreshing any time they want a job, it means their brain drops skills they learn that are closely related to the job they do. That means their experience is worthless -- they aren't retaining it, long-term.

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Re:Google Tech Dev Guide by LouisSayers on Wednesday December 19, 2018 @12:03AM (#18713161)
If the skills were closely related to your job, then it doesn’t make sense that you’d need to refresh those skills - as you would have been applying them at your job...

Sounds like the skills are the useless things, not the work experience.

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Re:Google Tech Dev Guide by m0zg on Wednesday December 19, 2018 @12:40AM (#18713334)
That's not the point. I just automatically assumed a subsequence problem will involve DP. I only know this because I studied for interviews in the past, not because I ever had to solve a subsequence problem at work, and I've done some _very_ advanced stuff.

I posit that ability to solve such problems is completely irrelevant to one's job performance, at Google or anywhere else. Google's own test of this hypothesis (hiring a control group of people irrespective of their interview scores) seems to bear it out.

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Re:Google Tech Dev Guide by SamReidHughes on Wednesday December 19, 2018 @07:47AM (#18715221)
The point is you are claiming that people need to study up a month for a Google interview. My point is that there are many people who do not need to study up for a month, or at all. They walk in, get asked some fun little data structures problems, and solve them.

This idea that some people like to push, that these interviews are all about memorization, is a false one.

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Re:Google Tech Dev Guide by webmaven on Wednesday December 19, 2018 @08:51AM (#18715553)
> Google's own test of this hypothesis (hiring a control group of people irrespective of their interview scores) seems to bear it out.

Link?

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Re:Google Tech Dev Guide by pathseeker on Wednesday December 19, 2018 @06:04AM (#18714813)
>But if they have to spend a month refreshing any time they want a job, it means their brain drops skills they learn that are closely related to the job they do. That means their experience is worthless -- they aren't retaining it, long-term.

DP isn't used the vast majority of the time. That's not retaining "experience".

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Re:Google Tech Dev Guide by SamReidHughes on Wednesday December 19, 2018 @08:03AM (#18715282)
Your experience from 10 years ago isn't used the vast majority of the time either.
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Re:Google Tech Dev Guide by AlexCoventry on Tuesday December 18, 2018 @11:02PM (#18712905)
> only non-bruteforce solution worth pursuing here involves DP

What's wrong with starting with a hashtable of substrings of fixed length? For inputs with low autocorrelation, that'll get you a good average-case speed up.

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