This is true - there are some people who can make C++ sing even for these kinds of problems, however most people who attempt to use C++ in an interview situatio

This is true - there are some people who can make C++ sing even for these kinds of problems, however most people who attempt to use C++ in an interview situation to solve toy interview problems do poorly. For most people, it takes them longer to solve the problem, to find and correct bugs and to provide tests that prove that they've solved the problem correctly than someone solving the same problem in a different language. I've noticed this in my own interviews, and this article mentions it too. It seems to me that the most natural explanations for this are either that the pool of C++ programmers has more bad programmers in it than other languages (which I don't believe) or the language and tools themselves are not as well suited to solving interview questions in interview situations. As to penalising people who switch languages for problems, if you give guidance that you want to see a solution in a particular language, that's fair enough, in any other case it seems unfair and misguided. Perhaps you don't really agree with 'right tool for the right job' when it comes to languages?