Ah, that's beautiful! ...and pure evil! I love it!

went full IOCCC on this one

unless you are counting whitespace

At this point, I'm not sure there are any more optimizations unless there is a "Martingale" instruction in the x86-64 architecture...

insidious laughter

Then the plan is working... (͠≖ ͜ʖ͠≖)

How about this?

Ah, you sorcerer you!

Is there any way to get this smaller? I can't think of anything else. You can change 100 to 1, then multiply the result by 100, but that seems to make it bigger overall (since you have to initially divide bank (b) by 100 as well).

I should have listened when the description said "this kata is not about coding skills..."

O( f(n) + g(n) ) due to calculating strlen every iteration

Very helpful error output! Clear, detailed, and insightful for the programmer. This should be more common!

Here strings :)

IMHO, if you don't want to complete the kata in a low-level language like C/C++ or assembly, then you can easily just complete it in Ruby/C#/Python. I agree this kata seems to be conceptualized more from a higher-level (scripting language) vantage point, but that shouldn't preclude someone from doing the harder work of completing those tasks (e.g., converting from string to double, simple validity checking for such a string, converting back to a string afterward) in a language like C, which in my opinion is still well-suited for the task, if you are familiar with the stdlib.

tl;dr: it seems like the critique is mostly that C has more complexity than C#, but I think unfortunately that if we remove the 'error checking' portion of the kata, it becomes more of an interpretation rather than a 'translation'. I appreciate the discourse.

C translation kumited. Please scrootinize and aproov!

Sorry, I started this, worked on it for about 5 minutes, and forgot about it (actually I didn't realize it was public). Feel free to do whatever you wish.

because clearly only someone who cares about the code would do this