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I've never asked FizzBuzz but I do regularly ask coding/algorithm questions. They are usually more difficult than FizzBuzz. I'd say around 80-90% can at least

by aplusbi 15y ago

I've never asked FizzBuzz but I do regularly ask coding/algorithm questions. They are usually more difficult than FizzBuzz. I'd say around 80-90% can at least come up with a solution in 45 minutes with some help. Probably less than 10% can come up with a good solution entirely on their own. I attribute this to two things, first I think our phone screenings work well enough to keep out people who really can't do FizzBuzz, and second that I'm fairly generous during interviews. I often don't expect real code, sometimes I'm satisfied with just a discussion of the algorithm (no white board coding at all). I don't expect code to compile and I even let candidates use undefined "helper" functions (although I usually only allow that if I get the feeling that they could implement them if asked). * For those that are curious I have two favorite questions - print out all the permutations of a given (ASCII) string and describe a search algorithm for a sorted array that has been split in two and the two pieces have been swapped (i.e. - 4,5,6,7,8,1,2,3).

pp13 15y ago
@aplusbi Let's say I interviewed you. I had asked to implement the fastest algorithm to give back the largest palindrome of words in English dictionary and compare it the largest palindrome of the french language. What the best solution you can come up with in 45 minutes. After, that I asked you, write a simple ftp server, in the language of your choice. With your first solution, I asked you implement a SSL library and add it to the ftp server to make it sftp. Based on that I can judge how good of a programmer you really are. Sorry for being sarcastic, but I think most interviewers are on a power trip. They ask questions that if they heard for the first time, they couldn't come up with answers either. I think your better off really talking about and going in depth with the programmers experience. If your experienced yourself, you should have no problem.
- eropple 15y ago
  His first question is very straightforward if you've ever encountered permutations in a math class (and you should have, if you're a programmer). Even if you haven't, it shouldn't be that difficult. His second is trickier, but solvable. And, no, I've never seen that (particular) question before.
  - pp13 15y ago
    My point was, his questions, doesn't really indicate if the candidate is a good programmer or not. It could be the person studied up on all sorts of puzzles and famous algorithms online but hasn't really written or programmed anything. Not all jobs require that much expertise. You could be doing some really simple programming work. I think most interviewers ask these type of questions 1.) make themselves feel smart 2.) they get a kick out it
    - eropple 15y ago
      That wasn't much of a point, on your part. The second question in particular requires some not-entirely-simple breaking down into subproblems. The first one can be handled in such a way if you're unfamiliar with the mathematics behind it; it's easier, as are many things, if you remember combinations and permutations from math class but not at all unsolvable if you don't. His questions aren't bad at demonstrating important aspects of a programmer's problem-solving approach. And your complaining that "not all jobs require that much expertise" is unfounded. I consider those to be novice questions, personally--and even if they weren't, you don't know what he's hiring for. He's not being unreasonable. You, on the other hand, seem to be, and seem to be doing so in a rather defensive manner.
    - pp13 15y ago
      @eropple So do you have data to back up your claims that; answering those questions determine if your a good programmer. Yes, there are tons of programming jobs out there, that don't require much of those skills. Not all jobs are that innovative. Most of the development jobs I have seen require you to come up to speed with the code base fast. So it's that code reading comprehension that I think is most prevalent.
      - eropple 15y ago
        I did not in any way, shape, or form claim that such questions determine whether or not a candidate is a good programmer. If you are going to respond to my posts, please respond to my posts and not what you think or wish I said in those posts. No interview or interview question can determine conclusively that you are a good programmer. But they reduce the likelihood that you're not, and comments like your strident and hysterical analogy drawn between these really very simple problems and "write a SSL library!" are doing little to change my mind.
- unshift 15y ago
  couldn't agree more. if i had to come up with a permutation algorithm as part of writing code, you'd better believe i'd look one up so that i'm sure i'm doing things optimally. i wouldn't trust myself to come up with the exactly right algorithm on the first try. if i had to deal with some weird half-sorted array, i assume i'd be working in the same context as the problem and wouldn't have to make up a solution on the spot with limited details. why do you have a weird-ass data structure like that to begin with? that's the first question i'd ask. personally i always ask a couple of simple questions (like FizzBuzz) and then talk experience. if you want to see a code sample, ask for one -- written on a computer, without someone hovering over the candidate's shoulder. coding solutions to weird questions on a whiteboard doesn't help anybody.
  - aplusbi 15y ago
    These questions aren't about "real world" situations, they are about problem solving and basic coding. Questions are good, as is a discussion on how and why these things should be implemented. For the split array problem I rarely ask for code (only when I think it will actually help the candidate), it's just a discussion. It usually goes something like this: Candidate: Well I can sort it first, then do a binary search. Me: How would you sort it? C: I'd use quicksort. M: Can you do better than an nlogn algorithm? C: Well I suppose since it's two pieces that are both already sorted, I can just find where they are split and then rearrange them. M: How would you find the split? C: I can go through each number until they stop increasing. And so forth. The "best" solution (that I've come up with, anyway) is to find the split using a modified binary search, and then use a regular binary search on the piece that might contain your query. Not everyone gets that and that's okay. In addition to asking coding questions I always ask candidates about previous experience and projects they've worked on. Sometimes the answers to these questions are more important. Most of the people I have been interviewing, however, are recent graduates or students who are just finishing college and may not have much experience or many projects that really engaged them. I spend a lot of time thinking about how I can improve interviews within the confines of how my company conducts them. I've stopped asking the permutations question as I feel that it has too much of the "aha!" factor in that either the programmer goes "aha!" and solves it or they don't.
- ig1 15y ago
  The problem with that is that there are plenty of programmers who can talk the talk without being good programmers.
- aplusbi 15y ago
  Like I said, 80-90% of candidates can answer my questions. I am also very generous with what I accept as an answer and how much help I give. My interview is as much a discussion about the question as it is the solution. As for what I get out of the interview - you're right, it's not going to tell me how good of a programmer the candidate is. But it will tell if they can code, and will give me some idea of their problem solving abilities. (I've also personally solved both questions without help in under 15 minutes each, though not under stressful interview conditions).

by aplusbi 15y ago

pp13 15y ago

@aplusbi Let's say I interviewed you. I had asked to implement the fastest algorithm to give back the largest palindrome of words in English dictionary and compare it the largest palindrome of the french language. What the best solution you can come up with in 45 minutes. After, that I asked you, write a simple ftp server, in the language of your choice. With your first solution, I asked you implement a SSL library and add it to the ftp server to make it sftp. Based on that I can judge how good of a programmer you really are. Sorry for being sarcastic, but I think most interviewers are on a power trip. They ask questions that if they heard for the first time, they couldn't come up with answers either. I think your better off really talking about and going in depth with the programmers experience. If your experienced yourself, you should have no problem.

eropple 15y ago
His first question is very straightforward if you've ever encountered permutations in a math class (and you should have, if you're a programmer). Even if you haven't, it shouldn't be that difficult. His second is trickier, but solvable. And, no, I've never seen that (particular) question before.
- pp13 15y ago
  My point was, his questions, doesn't really indicate if the candidate is a good programmer or not. It could be the person studied up on all sorts of puzzles and famous algorithms online but hasn't really written or programmed anything. Not all jobs require that much expertise. You could be doing some really simple programming work. I think most interviewers ask these type of questions 1.) make themselves feel smart 2.) they get a kick out it
  - eropple 15y ago
    That wasn't much of a point, on your part. The second question in particular requires some not-entirely-simple breaking down into subproblems. The first one can be handled in such a way if you're unfamiliar with the mathematics behind it; it's easier, as are many things, if you remember combinations and permutations from math class but not at all unsolvable if you don't. His questions aren't bad at demonstrating important aspects of a programmer's problem-solving approach. And your complaining that "not all jobs require that much expertise" is unfounded. I consider those to be novice questions, personally--and even if they weren't, you don't know what he's hiring for. He's not being unreasonable. You, on the other hand, seem to be, and seem to be doing so in a rather defensive manner.
  - pp13 15y ago
    @eropple So do you have data to back up your claims that; answering those questions determine if your a good programmer. Yes, there are tons of programming jobs out there, that don't require much of those skills. Not all jobs are that innovative. Most of the development jobs I have seen require you to come up to speed with the code base fast. So it's that code reading comprehension that I think is most prevalent.
    - eropple 15y ago
      I did not in any way, shape, or form claim that such questions determine whether or not a candidate is a good programmer. If you are going to respond to my posts, please respond to my posts and not what you think or wish I said in those posts. No interview or interview question can determine conclusively that you are a good programmer. But they reduce the likelihood that you're not, and comments like your strident and hysterical analogy drawn between these really very simple problems and "write a SSL library!" are doing little to change my mind.
unshift 15y ago
couldn't agree more. if i had to come up with a permutation algorithm as part of writing code, you'd better believe i'd look one up so that i'm sure i'm doing things optimally. i wouldn't trust myself to come up with the exactly right algorithm on the first try. if i had to deal with some weird half-sorted array, i assume i'd be working in the same context as the problem and wouldn't have to make up a solution on the spot with limited details. why do you have a weird-ass data structure like that to begin with? that's the first question i'd ask. personally i always ask a couple of simple questions (like FizzBuzz) and then talk experience. if you want to see a code sample, ask for one -- written on a computer, without someone hovering over the candidate's shoulder. coding solutions to weird questions on a whiteboard doesn't help anybody.
- aplusbi 15y ago
  These questions aren't about "real world" situations, they are about problem solving and basic coding. Questions are good, as is a discussion on how and why these things should be implemented. For the split array problem I rarely ask for code (only when I think it will actually help the candidate), it's just a discussion. It usually goes something like this: Candidate: Well I can sort it first, then do a binary search. Me: How would you sort it? C: I'd use quicksort. M: Can you do better than an nlogn algorithm? C: Well I suppose since it's two pieces that are both already sorted, I can just find where they are split and then rearrange them. M: How would you find the split? C: I can go through each number until they stop increasing. And so forth. The "best" solution (that I've come up with, anyway) is to find the split using a modified binary search, and then use a regular binary search on the piece that might contain your query. Not everyone gets that and that's okay. In addition to asking coding questions I always ask candidates about previous experience and projects they've worked on. Sometimes the answers to these questions are more important. Most of the people I have been interviewing, however, are recent graduates or students who are just finishing college and may not have much experience or many projects that really engaged them. I spend a lot of time thinking about how I can improve interviews within the confines of how my company conducts them. I've stopped asking the permutations question as I feel that it has too much of the "aha!" factor in that either the programmer goes "aha!" and solves it or they don't.
ig1 15y ago
The problem with that is that there are plenty of programmers who can talk the talk without being good programmers.
aplusbi 15y ago
Like I said, 80-90% of candidates can answer my questions. I am also very generous with what I accept as an answer and how much help I give. My interview is as much a discussion about the question as it is the solution. As for what I get out of the interview - you're right, it's not going to tell me how good of a programmer the candidate is. But it will tell if they can code, and will give me some idea of their problem solving abilities. (I've also personally solved both questions without help in under 15 minutes each, though not under stressful interview conditions).