Please give these guidelines a read. Particularly, try to look at this example as a good idea of how the tests should be formatted: try to avoid using preloaded, as the guidelines state, and instead of std::cout, supply an ExtraMessage argument to Assert::That. Also the if (r > INT_MAX) branch seems redundant to me since the maximum value generated by your tests, (INT_MAX / 1024) + 200000 * 1000 is still less than INT_MAX. Make sure every code snippet begins with any and all headers used in that snippet

c++ translation: https://www.codewars.com/kumite/6641ca9f5b211314c218f362?sel=6641ca9f5b211314c218f362

If my understanding is correct, when the 2nd parameter ("b", in your case) is 2 or 3, the expected value of n3 should be equal to n2, but n3 is actually set to 0 by your code.

Pure maths. It's nice to be able to switch off from programming every now and then and pretend I'm a mathematician ;-)