[TUHS] Unix v7 icheck dup problem

[Bakul Shah]

On Mar 1, 2023, at 5:36 PM, Noel Chiappa <jnc at mercury.lcs.mit.edu> wrote:
> 
> Steve Ward told another oral story which I'm pretty sure _is_ true, though.
> They ask the candidate to design a state machine (or digital logic, I forget
> which) which can tell if a number is divisible by three (I think I have the
> details correct, but I'm not absolutely certain). So they describe one - and
> then point out that you can feed the number in from either end (most or least
> significant end first) - and proves that it will work either way! The
> committee was blown away.

Doesn't everyone know that a number is divisible by 3 if the one digit
result after casting out 9s is divisible by 3?