zlacker

This particular problem (number of digits in a number) is actually monumentally important for performance reasons for e.g. json generation. See https://m.facebook.com/notes/facebook-engineering/three-opti... for details.

That said, I do agree that as stated the problem is a toy. The problem statement could at least motivate the lack of string operations - i.e. pretend you’re the language designer and you’re tasked with implementing str(int) in C. Just saying “don’t do that” isn’t helpful. Gaining an understanding that nothing is magical is useful though.

>>NightM+(OP)
That link has a very insightful discussion (and incidentally provides a nice fast correct solution, and use case, for the initial problem!).

>>NightM+(OP)
Probably the students do not know about big O notation at this point, but requiring a solution that uses at most O(1) additional space would be enough. Then again, automatic bignums in python make it hard to evaluate the space complexity.