3 ms·
This question has an "a-ha" moment, but it is not required to solve the problem adequately. I wholeheartedly disagree with this statement: > People like to pos
by mankyd 12y ago
This question has an "a-ha" moment, but it is not required to solve the problem adequately. I wholeheartedly disagree with this statement:
> People like to pose puzzlers to “see how people think” but that’s nonsense in the case of puzzler questions. You can’t reason your way through a puzzler, that’s why it’s a puzzler
There are plenty of ways to solve this problem. They're not all optimal, of course, but you don't ask these questions to get the optimal solution, you ask these questions to understand how the person reasons about them.
This more falls on the interviewer than the candidate. It's upon the interviewer to encourage a dialogue about the problem and talk aloud through it.
Yes, some qualified candidates are bad at this. I'm sorry to hear that, but it can be practiced. Being good at interviewing can be learned. It's not terribly difficult. My number one pro-tip? Never do this:
> If you don’t have the a-ha moment in the interview, you won’t get it, and a good chunk of your brain will be devoted to thinking “oh shit I’m blowing this interview” rather than focusing on the question at hand.
Never think that you're blowing the interview. I got a job at Google and I know for a fact that I didn't get the optimal solution to some of my questions. It's not about the solution, it's about the process.
- mathattack 12y agoGoogle and others have largely given up on these types of brain teasers. http://www.nytimes.com/2013/06/20/business/in-head-hunting-big-data-may-not-be-such-a-big-deal.html http://www.nytimes.com/2013/06/20/business/in-head-hunting-b...
- mankyd 12y agoThis is... debatable. It depends on what you consider a puzzler. I will tell you that I was asked questions similar to the one referenced in the parent article. It is a programming question that can be answered precisely with code, and that code can then be analyzed for time and memory considerations. I was not asked silly questions like "how many golf balls could you fit in a school bus" or "how do you move a mountain 3 feet to the side". These are the types of questions he explicitly references in the article. edit: I will also add that there are differences between eng and non-eng interviews. I'm not familiar with the non-eng process really.
- mathattack 12y agoI used to have a math puzzler that I'd ask. Almost nobody got it right. One guy got close, and we ultimately hired him. He asked for the full answer, and I gave it to him. He told me I was wrong. I pointed out that I had asked this question at least 50 times, and knew it in and out, and that he should reconsider. Then he sent me a spreadsheet proving that I was wrong. Whoops.
- zheshishei 12y agoSo, if the guy "got close", but then proved that you were wrong, was his answer was actually right, but that you thought it was wrong?
- mathattack 12y agoYes. Much to my chagrin. But I was glad we hired him because he was smart and thorough, and only rubbed my nose in it once or twice.
- raldi 12y agoWhat was the puzzle?
- deleted 12y ago[deleted]
- deleted 12y ago[deleted]
- gibybo 12y agoYou can't tease us with such a question and not tell us what it is! Or perhaps you're still using it and don't want to reveal it publicly? :(
- mathattack 12y agoIt's a question that checks intuition on probability and the law of large #s. I don't want to give too much more since I do pull it out on the very rare instance where someone is very bold about their stats knowledge.
- reledi 12y ago> Never think that you're blowing the interview. How do you that? Because that's all I ever think about once I mess up during interviews, and it's all downhill from there.
- mankyd 12y agoIf you mess up, say so: "Oh, that's completely wrong. Huh. Ok, let's fix it." Again, these interviews are more about seeing how you reason about a problem. People make mistakes all the time - wrong assumptions, incomplete solutions, etc. What matters is what you do once you realize there's a problem.
- alok-g 12y agoIn theory, yes. In practice, you may lose even if the interviewer is wrong. I have. At some big-name companies. Just for example, an interviewer at Apple was adamant that frequency can never be negative. Whatever happens to Fourier transform that integrates frequency from negative infinity to positive infinity. I have more examples. :-)
- dllthomas 12y agoYeah, I think I once lost out on a Google interview in part because the interviewer lacked the math to follow my reasoning (also, they were attempting to get me to a different solution by applying criteria that my existing solution already adhered to better than what they wanted).
- mankyd 12y agoThis may very well be, but there's not much you can do about it at that point but continue to try to fix the problem. If you can't be amicable about it with the interviewer, then either they don't want to work you or you don't want to work with them (probably both). Might as well make the best of it.
- reledi 12y agoI don't have any trouble admitting I made a mistake when I notice it, it's recovering from it. At that point I think about how I messed up, what I should have done, and how bad the rest of the interview will go. In every day life, this is not the thought process I go through if I make a mistake. But in an interview the stakes are higher, you'll be quickly discarded if you don't do well.
- pekk 12y agoWhat a great solution. "Just don't feel anxious." Obviously if someone is lacking in confidence, is anxious or is a humble person, they should just learn not to be that person any more so they can get a Google job like you, the paragon of success. Otherwise, they DESERVE to be judged as unqualified. That certainly follows.
- mankyd 12y agoHa! I am hardly the paragon of success. You judge my words too harshly. I am simply pointing out that, yes, companies conduct interviews by asking coding questions. Yes, some of the questions are hard and don't have obvious optimal solutions. Don't panic just because you don't get 100%.
- joesmo 12y agoI've never been asked such a question, provided a sub-optimal answer, and been allowed to continue. Every single time, the next question then is 'Can you make it <faster|better|etc.>?' Maybe, but by this point, I already know this is a terrible place to work.
- mankyd 12y agoI've been in this exact same situation. And I was offered positions. I guess that's my point - I didn't always find the perfect solution. I was pressed to continue to think about the problem until whatever allotted time was up. I wasn't [entirely] judged based on my final solution; I was judged on my ability to reason about the problem and demonstrate competency in my coding abilities.
- danielweber 12y agoPlaces that encourage me to find the best answer are good.
- marcosdumay 12y ago> Yes, some qualified candidates are bad at this. I'm sorry to hear that, but it can be practiced. Being good at interviewing can be learned. Do you interview people to discover if they are good on the job, or just to discover if they are good at interviewing?