Not sure if possible, but you could perhaps #define while cheat_detection(); while
It doesn't matter that that turns it into two statements, just as long as the cheat_detection() is called you will (silently) fail the test. Be sure to VERY CLEARLY state that 'while' is not allowed to be used ;).

If people know you do this they can work around it, of course.

I am not happy. I spent a lot of time on writing a solution that is O(log(n)) because the description said it was necessary to write an efficient algorithm (and it should be); then I find out that everyone else wrote a simplistic O(n) "solution" and got away with it. :/ That is not right.

The program of Complex #2 jumps passed the end of the program.
It ends with:

...
jnz 5 10
mov c a

So, that DOES jump - because it jumps when 5 != 0, and
advances 10 places, which is way behond the end of the program.

I'm a speed freak, so I always try to write a solution that is fast - but you beat me with this solution lol. You're totally right though: since the answer had to fit in a long long, there are only a very limited number of possibilities. I think you cracked/invalidated this kata!