Simply by mistake.
:D

P.S. I'm sorry.

Hint: try counting braces.

Approved!

Approved!

There is one more test group: super_input.
The input is randomly generated and is 10 times larger than large_input.

Timeout may be caused by string operations.

Kept in both cases.

N.B. I don't like C++ assertion library used on Codewars...

Anyway, I've fixed that part.

It must be caused by the solution validation assertion. Some of the tests are quite large and can't possibly be written to STDOUT.
I'm currently looking for some assertion documentation to rewrite that part (remove standard assertion output).

It works!

Yes, I agree. But there is no point in using that expression in programm.

If so, C version should be corrected.

Is it guaranteed that there won't be any input which results in negative discriminant?

What precision is required?
The difference between my solution's output and expected value is about 10^-17. Should it be considered as an error?
Input: 0.11.

@simonvpe:
It makes heavy use of the cache and the complexity is O(1) in best case, and O(n) in case there are only nested "bogus" sequences like [[<>]].

Do you mean, O(n) iterations through the source_code string? That gives you O(n²).

UPD. My bad, I've got your idea just now. It seems to be optimal enough, but there may be small hateful bug, which makes you suffer.

P.S. Finally there is one solution (except mine), so I believe that kata is solvable.