Comment by torginus

I'd say I'd decompose this into 2 'units'

- iterate through the array arr,

- sum its elements

of course, since C is a low level language, implementation details seep in there but those are the 2 major logical concepts that mentally can be quickly parsed as a single unit each.

Some languages allow reductions on collections, so the actual iteration becomes logically part of that single unit, so it might count as one, but I'd say that's the absolute upper bound of complexity you should stuff into a singlwe line.

The goal here is to make every statement conform to a template so that your brain quickly recognizes it and you can move on, rather than you having to break it apart bit by bit to figure out the goal.