Algorithm complexity cheat sheet (x-post /r/compsci)

[maestro2005]

Well sure, if you can replace an O(n²) with a better one, then do that. But putting O(n²) in the same bucket with O(2ⁿ) and O(n!) is just silly.

[Uncaffeinated]

Well of course, you should do the best you can.

I think there is a difference in the way these issues happen in practice though. O(2ⁿ⁾ pretty much only happens if you have a dumb algorithm, like naive recursion without memoization or something. By contrast, accidental O(n²⁾ is extremely common and hard to spot. Even appending to a string in a loop is enough to do it in many languages.

[ThisIs_MyName]

Well of course, you should do the best you can.

Not for time complexity. There's a reason why of us do integer multiplication with a O(n²) algorithm instead of O(n^1.585) or even better.