Resolving; almost certainly not a kata issue.

There are plenty of working C++ solutions and I've just written another to double-check - the random tests do not seem to have any issues, and I attempted them many times to be sure.

You can attach your code here as long as you're using spoiler tags. I suggest however that you're probably just mishandling floats; it would be easy to do so on this kata and the solution as described in the instructions works otherwise.