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Comment by mquander | Hacker News Reader

This is getting to be a really silly off-topic discussion, but I have to admit, I would be totally curious to hear if you could identify what is difficult for you about this task:

A) Pressure of an interview situation makes it hard to think straight?

B) Absence of familiar IDE, environment, REPL/compile-run cycle makes it hard to work or think effectively?

C) Something else?

I just don't see how it could be difficult for someone who understands loops and pointers (as I assume you certainly do.) I would have filed "reversing a linked list" under the Fizzbuzz category of things-that-anyone-who-has-ever-actually-programmed-can-do.

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I am not a stupid copy/paste programmer who doesn't know what the fuck she's doing. Trust me on that. As my blogpost said, I thoroughly understand the concepts. But if you read my blogpost comments, you'll notice that many people sympathize -- and I doubt that these people are incompetent. Some people will impress at whiteboard coding, others will not. That's it.

When I first started programming I was doing VBA on spreadsheets. I thought entirely in terms of simple commands, variables, events, if statements and the occasional loop. I could vaguely remember what an array was from highschool but never needed one (although, to be fair, I had a spreadsheet to work with).

I did not have a clue about objects, classes, pointers (Pass By Val vs Pass By Ref was like flipping a coin), never mind linked lists. But despite this, I managed to get a lot done. Of course since I've taken the time to educate myself I understand now, but my point is in some settings you can go quite far without ever engaging the fundamentals of computer science.

I know the OP said she does understand all that stuff but it's also possible she barely needs to use it.

Maybe it's the "computer scienciness" of the term. I'm a practical programmer with a tiny bit of industry experience, and have only just started attending university. And I'm intimidated by it all. Memory allocation! Pointers! My brain shuts down and I imagine anything I say will put McCarthy in the grave and cause Dijkstra to rise from it.

But the first time I read some blogger ragging on interviewees who didn't know how to reverse a linked list, I read the first sentence of the wikipedia article and realized it would be easy to do (albeit probably not elegantly): just loop over the list doing push/pop operations.

It's a pretty easy solution, and already runs in O(n) time, so I'm not sure why I doubt myself. It's probably that although I'm used to devising solutions for complex problems, I'm unused to problems that are formally defined.

I think that sounds like probably a big component. I do know what you mean -- something about the words "linked list" seems complicated, even though there's nothing much simpler than an actual linked list.

I wonder if people who would freeze at a question about reversing a linked list could answer that and similar questions if they were turned into "word problems" somehow; e.g. evilduck in another comment compared it to reversing the order of charms on a bracelet. Although I can't think of any examples that doesn't sound terribly contrived.

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