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Comment by nandemo | Hacker News Reader

I got that book. While the questions and answers are useful, in my experience this book alone is nowhere near enough to get prepared for a Google interview (not that the author claims that).

I studied CLRS's Introduction to Algorithms and a couple of other books for about 2 months. Even then I could not answer the hardest questions during the onsite interview. And if you cannot come up with an optimal algorithm for a given problem, all of the items mentioned in the article (communication, clear coding, testing) don't really matter.

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I interview for Google.

I gave my question to an algorithms professor and he didn't get the optimal answer.

Needless to say, I don't expect candidates to get the optimal answer.

>And if you cannot come up with an optimal algorithm for a given problem, all of the items mentioned in the article (communication, clear coding, testing) don't really matter.

That's just not true and if any company is only interested in whether or not I can generate a correct answer under pressure in 20 minutes, then I'm not interested in working for you.

You seem to be disagreeing with something I haven't said. I'm simply describing my experience interviewing at Google: I didn't give an optimal solution to a couple of problems, and didn't get an offer. So I infer that the other items mentioned in the article don't matter as much for getting a job at Google.

You also did not wear a pink and blue striped hat, and did not get an offer. And yet, you seem to not connect your failure to wear a pink and blue striped hat with your failure to get an offer.

I'd suggest you read the section in the article about how you're evaluated. Yes, how optimal your solution is matters -- of course it does. This doesn't mean that you have to get an optimal answer though. You have to do better than the majority of candidates (maybe ~80% of candidates).

For some problems, being in the top 20% of candidate will mean getting the optimal solution. In other cases, it may not. The optimal algorithm might be trivial, and it might be more about coding skills. In another problem, it might be totally unrealistic to expect that a candidate needs to get the optimal algorithm.

Additionally, you seem to assume that since (according to you) getting the optimal answer is necessary, that it must also be a sufficient condition. That's obviously false. It's entirely possible that a candidate needs to get the optimal answer AND implement it well, in which case these other factors come into play.

> You also did not wear a pink and blue striped hat, and did not get an offer.

I don't understand the point of this quibbling.

Say I was asked 30 questions; I missed 3 of them and didn't get hired. It's a reasonable to assume that these 3 questions were considered important in the general assessment.

> You have to do better than the majority of candidates (maybe ~80% of candidates).

I know, I said I read your book. ;-)

But that doesn't substantially change the story, it means it's likely other candidates got the optimal solution or got closer to it.

Of course this is all based on my self-assessment, since Google doesn't provide any sort of feedback post-interview. But I'm pretty confident that I went well in the other questions. 4 out of 5 interviewers were pretty nice in giving feedback during the interview, even if indirectly. E.g. they'd ask progressively more involved questions on the same topic, so I more or less knew when I had answered the previous questions correctly.

> Additionally, you seem to assume that since (according to you) getting the optimal answer is necessary, that it must also be a sufficient condition. That's obviously false.

No, I haven't made any such assumption. I only assume that getting the optimal answer was the "high bit" in my case.

Apparently this works for Google, and unlike other people who have failed to get the grapes, I don't call them sour.

You weren't just asked 30 questions. You were asked 30 questions and evaluated on dozens of other non-answer based factors.

Imagine: I walk in, get 27/30 and then proceed to be a sexist bigot who says I refuse to work on a team with gays or women and I decide to start claiming that you have to get 100% to get hired.

I'm not saying you did something like that, but you're just automatically assuming that that question was the pinnacle of your rejection and not the other things listed.

I mean, unless you've been implicitly implying that you're a perfect interviewer minus the 3/30 you missed...

"Say I was asked 30 questions; I missed 3 of them and didn't get hired. It's a reasonable to assume that these 3 questions were considered important in the general assessment."

That would be true if those answers were assess on a strictly correct / incorrect basis AND those were the only things you were assessed on. Neither of those are true though in this case.

It's very possible that the questions where you didn't get an optimal answer you actually did very well on. And that there are other questions where you got the optimal answer, but it took you too long or you made too many mistakes in coding. Or you just came off as arrogant. Who knows?

I've seen many many candidates make similar assumptions to yours -- thinking they bombed specific interviews, when in fact they did very well on those. You might be correct about why you got rejected. But it's even more likely that you're wrong.

But this is absolutely true: getting the optimal solution in all interviews is not a necessary and sufficient condition.

It's not uncommon for interviewers to ask a few warm up/intro questions and then proceed to more advanced questions--so if you didn't get a few questions right, you may simply have missed some easy ones, so they didn't ask you the hard ones. This would leave you the impression that you "almost" made it, when in fact you may not have come close.

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