Which is better coding style?

Is better to code
1. In a way can be readable easily on first sight but maybe inefficient
or
2. That is very efficient and short but more complicated to read and understand

My instructor (a very scary prof) always tells us to go to option #1. Yes you can still do option #2 if you provider enough comments to explain.

But if you do option #1, you will not need to comment alot about your code because your code will speak for itself because of its easy readability.

What do you think?

>>9
Signed as well.

I grade a lot of C++ homework for my uni, and I usually see a bunch of failed attempts at #2. (like >>10 said - overkill)

I also do freelance programming and I have to work with a ton of poorly written attempts at #2 (with no comments and variables in fucking german) and I feel like stabbing the hell out of the previous developer. Seriously, do your fellow programmer a favor and just stick to neatness. *twitch*