Re: Zeller's Algorithm

[Robert A Duff <bobduff@shell01.TheWorld.com>]

"Frank J. Lhota" <NOSPAM.lhota.adarose@verizon.net> writes:

> > This may be a problem in languages
> > such as C, where e.g. -30 % 7 = -2.
> 
> Actually, the C standard does not require that (-30) % 7 == (-2). The
> standard has somewhat loose requirements here that would allow the C "%"
> operator to behave either like the Ada "rem" operator, or like the Ada "mod"
> operator. The drive to standardize C, unfortunately, came after there were
> many divergent implementations of the language. The need to validate
> existing implementations tied the hands of the standards committee.

Doesn't this make the % operator totally useless for negative numbers?
I mean, how do you write code that gets some useful "right" answer,
if you're doing % on negative numbers?

- Bob