That's what I meant so I've edited my comment to hopefully make that a bit clearer. Having actually tested it, because in C++ I use true/false, it is 0 that equals false and anything else is true. You'll have to forgive my lack of clarity. It's 03:02 and I've had about 2 hours sleep tonight and won't be getting any more. Time for a coffee.
Assuming yes and no means true and false, c has numbers (1, 0) for yes and no and c++ can use those numbers for yes and no because it is a superset of c.
Technically, it's 0 and non-0 but I always use 1. They are integers rather than keywords.
Clinger not cancer. I hope.