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| -rw-r--r-- | challenge-019/randy-lauen/ch-1.p6 | 70 |
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diff --git a/challenge-019/randy-lauen/ch-1.p6 b/challenge-019/randy-lauen/ch-1.p6 new file mode 100644 index 0000000000..121f603290 --- /dev/null +++ b/challenge-019/randy-lauen/ch-1.p6 @@ -0,0 +1,70 @@ +#!/usr/bin/env perl6 + +=begin SYNOPSIS + +Write a script to display months from the year 1900 to 2019 where you find 5 weekends +i.e. 5 Friday, 5 Saturday and 5 Sunday. + +Usage: + $ perl6 ch-1.p6 --from=YYYY --to=YYYY + +Example output: + $ perl6 ch-1.p6 --from=1900 --to=2019 + Found 119 months with 5 full weekends + 1901: Mar + 1902: Aug + 1903: May + 1904: Jan, Jul + ... + 2017: Dec + 2019: Mar + +=end SYNOPSIS + +role MonthRole { + method has-five-full-weekends { + # The month must have 31 days. + return False unless self.days-in-month == 31; + # The month must begin on a Friday. + my $date = self.day == 1 ?? self !! Date.new( self.year, self.month, 1 ); + return $date.day-of-week == 5; + } + + method month-name-short { + given self.month { + when 1 { 'Jan' } + when 2 { 'Feb' } + when 3 { 'Mar' } + when 4 { 'Apr' } + when 5 { 'May' } + when 6 { 'Jun' } + when 7 { 'Jul' } + when 8 { 'Aug' } + when 9 { 'Sep' } + when 10 { 'Oct' } + when 11 { 'Nov' } + when 12 { 'Dec' } + } + } +} + +sub find-months( $from, $to ) { + my @matches; + for $from .. $to -> $year { + for 1 .. 12 -> $month { + my $date = Date.new($year,$month,1) but MonthRole; + push @matches, $date if $date.has-five-full-weekends; + } + } + return @matches; +} + +sub MAIN( :$from!, :$to! ) { + my @matches = find-months( $from, $to ); + say "Found @matches.elems() months with 5 full weekends"; + for @matches.classify( { .year } ).pairs.sort({ .key }) -> $pair { + say "{$pair.key}: { $pair.value>>.month-name-short.join(', ') }"; + } +} + + |