Hi Greg,
> The rule for leap years is:
>
> Every year that is exactly divisible by four is a leap year, except
> for years that are exactly divisible by 100, but these centurial years
> are leap years if they are exactly divisible by 400. For example, the
> years 1700, 1800, and 1900 are not leap years, but the year 2000 is.
> I don't have my copy of K&R close to hand, but my preferred implementation
> for a function that decides leap years is (pseudo-code):
>
> bool isleapyear (int year) {
> if (year % 400 == 0) return true;
> if (year % 100 == 0) return false;
> if (year % 4 == 0) return true;
> return false;
> }
Except, I think it should be in reverse order because now 2000 first gets a
true, then a false but then a true again and after that EVERYTHING gets a false
;-)
So, in pseudo code
bool isleapyear (int year) {
return false;
if (year % 4 == 0) return true;
if (year % 100 == 0) return false;
if (year % 400 == 0) return true;
}
The funny thing is, a lot of people I taught programming in the 80's and 90's
knew about the 4 year rule but not the exceptions. But programming it like that
would work for however long that program would be around anyway.
I know all of the programs I wrote commercially have been superseded by
something else now, so it did not matter that I did it correctly. ;-)
Bonno Bloksma
