I'd say it's the opposite. I've never heard quicksort referred to as a O(n^2) algorithm for example, always as an O(n log n) algorithm with O(n^2) worst-case. M

I'd say it's the opposite. I've never heard quicksort referred to as a O(n^2) algorithm for example, always as an O(n log n) algorithm with O(n^2) worst-case. Maybe in an interview you would explicitly say average-case, but I think that's more to show the interviewers that you realize that a single algorithm can have multiple big-Os.