Create an article similar to https://docs.codewars.com/languages/python/authoring/ but for C++.

Points needing particular attention:

• includes (missing includes, C includes)
• random utilities
• stringizers
• custom assertion messages (modifications to the testing framework: Add overloads to show additional custom message on failure snowhouse#3 )
• compilation warnings
• input and output values: const ref vs value, replacements for arrays and std::vector
• avoid C: strings, arrays
• input modification, changing the signature of solution function