On Thu, Feb 07, 2002 at 09:16:55AM -0000, Lars Henrik Mathiesen wrote: > [EMAIL PROTECTED] (Bill -OSX- Jones) writes: > >I was asked recently if I could write a Perl program that > >would find out when the next time Christmas day would > >actually be on a Sunday. > > You could try golfing on this algorithm (left relatively readable): > > #!perl -l > $y=4-16*shift;$y+=(6,11,6,5)[$x++%4]until$y>(localtime)[5];print$y+1900 > > This takes a day number argument (0=Sunday to 7=Sunday); just remove > '-16*shift' to get a Sunday-only version. It won't print the current > year even if it fits, and it's only valid if run between 1900-01-01 > and 2089-12-31 (2094-12-31 for Sundays only).
Or this: #!perl -l $_=shift;1while++$_,/(.+)(..)/,(8+$2*5/4-2*($1%4))%7;print This doesn't take a day number, but does work for all years from 1748 onwards given a year as argument. It won't print the starting year even if it fits. -- Matthew Winn ([EMAIL PROTECTED])
