I do that too. It seems more in the spirit of the problem. For an alternate problem, in which you are asked to print strings a, b and c (!= a concat b) if the n

I do that too. It seems more in the spirit of the problem. For an alternate problem, in which you are asked to print strings a, b and c (!= a concat b) if the number is divisible by 3, 5 and 15 respectively, it makes sense to special case 15.