[dahart]

Ugh.

The “worst case” is the part referring to the upper bound. Big-O is referring to the “order” of the run time, meaning the largest term in the formula for large n.

Again, everyone knows this if they know Big-O at all. I am intentionally not being picky and pedantic with my words, because the context of this thread was people complaining about unnecessary formality and unnecessary and unhelpful over-concern about academic correctness rather than practicality. There is no widespread misconception, but there are people who like to wax philosophical and try to demonstrate their superior knowledge...

My side intention was to detail why @rafiki6 might have been incorrect without knowing it, since they claimed correctness and complained about downvotes.