Since the code does not matter, you wouldn’t need or want to phrase it in terms of algorithmic complexity. You surely would have a more real world requirement, like, if the data set has X elements then it should be processed within Y milliseconds. The AI is free to implement that however it likes.
If you have particular performance requirements like that, then include them. Test for them. You still don’t have to actually look at the code. Either the software meets expectations or it doesn’t, and keep having AI work at it until you’re satisfied.
And that is the right assumption. Why would any humans need (or even want) to look at code any more? That’s like saying you want to go manually inspect the oil refinery every time you fill your car up with gas. Absurd.
And there was a time when using libraries and frameworks was the right thing to do, for that very reason. But LLMs have the equivalent of way more experience than any single programmer, and can generate just the bit of code that you actually need, without having to include the whole framework.