DEV Community

Discussion on: Big-O Cheat Sheet

Collapse
 
deciduously profile image
Ben Lovy • Edited

This is a good point, of course rote memorization will not replace actual understanding, and one would hope any decent interviewer would be able to instantly tell the difference. I don't think the point of charts like these is to cheat at interviews.

That said:

I've never had an interview where someone asked me about any of these CS algorithms/data structures.

This likely varies by job domain/region/experience/whatever - I've only had one interview where I wasn't asked some arbitrary academic question about a data structure I'd never need to know in practice. Technical interviews are pretty varied, and usually broken, but this sort of thing has definitely been a theme for me. Usually in the context of a challenge problem, like you said, but I've been asked to cough up and compare and contrast options to fit a problem. A huge theme of my interview experience is "okay, tell me what the Big-O of your current solution is, and then improve it given the data is constrained by whatever". Studying a chart like this helps me, at least, even though I do understand conceptually why the values are what they are.

Collapse
 
aleksandrhovhannisyan profile image
Aleksandr Hovhannisyan

and usually broken

You can say that again.

I once had a phone screen where I was asked to estimate how many feathers would fit inside the volume of your typical brick.

That was my biggest WTF interview to date.

Fortunately, my other interviews have been pretty pleasant (so far).

Thread Thread
 
deciduously profile image
Ben Lovy

So, yeah, I agree, that's ridiculous. I do sorta see what they're getting at though - they want to hear you talk it through. My similar example is "how many gas stations are there in the Continental US?". Who knows or cares about the answer, but a dev employer would care about how you approach the problem.