You don't know how to transform the string "12345" to "12346" in a mainstream PL?
I don't think "valid applicant" and "doesn't really grok strings/types" are compatible, outside of intern/maybe junior positions. The filter works.
I don't think "valid applicant" and "doesn't really grok strings/types" are compatible, outside of intern/maybe junior positions. The filter works.
Another possibility is nerves. Early in my career I was very nervous in interviews and I have sympathy. I have fucked up the most basic search algorithms completely and spewed gibberish when asked to explain the complexity of my solution.
I have sympathy for that, but the only way to get through interview nerves is exposure therapy. At least in my experience.
You’re given `99999`. Increment it. A naive approach would turn this into `9999:`. Making this work is a bit complicated and involves memory reallocation if you’re in a C-like language and you need to increase the length of the string in order to increment it. You’ll probably want a system where the caller passes a buffer of sufficient size to use for rewriting the string, in case you overflow. Make sure to have a way for the caller to pass the buffer length. You don’t want to allocate because that’s not the way it should be done in C, callers should generally allocate. You could use atoi, increment, and itoa to go back again, but that’s probably “cheating” from the perspective of a leetcode advocate, they likely want you to do this without the stdlib conversion functions.
There’s a bazillion reasons why this sucks as an interview question. There’s no way a correct answer is just something you’ll “get in 15 seconds”.
If you're not allowed to use atoi and itoa, it's still not all that difficult to do in C. Incrementing ASCII characters and handling carries is really trivial.
I'd be kind of worried if I was hiring a C developer who didn't know the basic things you described above. I'm not sure why you think those are esoteric concepts that we shouldn't expect developers to know.
This actually does seem like a great icebreaker-type question for a C developer. I'm less convinced every developer should be able to go into that level of detail if they are doing Javascript or Python or whatever. Ideally they'd be able to at least reason through some of this and demonstrate some understanding of some of this, but I'm not sure it is a great icebreaker question for all developer roles.
An O(1) in-place solution with a sane API exists in C++ and the form of it is also a handy indicator of whether candidate who proposes solving this in C++ is familiar with more recent standards or not.
Are you starting to see why this is a good icebreaker? It has all kinds of discussion potential.
That baffled me for a moment, then I realized you were talking about the general case of a uniform random input where a carry for the 1s digit has probability 0.1, a carry for the 10s digit 0.01, etc., and all 9s is the pathological worst case, right? That's what I get for coming into the discussion sideways.
Of course there is a trivial solution in pretty much any language, for example something like str(Decimal(x) + 1) in python. That's dead-simple and anyone should be able to do at least that.
The later addendum that they want someone to know how data is store by the computer seems to imply that they want an answer that doesn't use these conversions, which gets a lot trickier depending on the context. I think you'd still expect someone who does C/C++ work to get there pretty quickly, but it is more than 15 seconds - you have to think about some corner cases and how you handle the string having to be resized in some situations.
But in some languages, it isn't obvious to me how you'd do it (especially since strings are immutable in many languages) and I think it is maybe a bit unfair to ask someone who does Java or Python or whatever to do it off the top of their head.
Problem solving isn't orthogonal to having genuine expertise. Loads of awful, brittle, hard-to-read, but working, code gets written every day by people who are good at finding a solution but haven't RTFM, so to speak.
for example, if you are using strings to do addition, why the fuck aren't you allows to to atoi? also, why are you using strings to hold numbers?
everything to do with that question is something that you'd insta-reject in a diff/pr/mr.
Surely converting from string to int, validating it, catching errors and generally making it nice, is a much better test?
Its like going to an interview for a copywriter(someone who writes text) for safety sign company, and they ask you to make a riddle in English, but you can't use any words that are derived from Latin. Sure it shows an impressive command of both etymology and english, but its totally opposite to making clear, easy to understand text.