RosettaCodeData/Task/UPC/Perl/upc.pl

49 lines
2.3 KiB
Perl

use strict;
use warnings;
use feature 'say';
sub decode_UPC {
my($line) = @_;
my(%pattern_to_digit_1,%pattern_to_digit_2,@patterns1,@patterns2,@digits,$sum);
for my $p (' ## #', ' ## #', ' # ##', ' #### #', ' # ##', ' ## #', ' # ####', ' ### ##', ' ## ###', ' # ##') {
push @patterns1, $p;
push @patterns2, $p =~ tr/# / #/r;
}
$pattern_to_digit_1{$patterns1[$_]} = $_ for 0..$#patterns1;
$pattern_to_digit_2{$patterns2[$_]} = $_ for 0..$#patterns2;
my $re = '\s*# #\s*' .
"(?<match1>(?:@{[join '|', @patterns1]}){6})" .
'\s*# #\s*' .
"(?<match2>(?:@{[join '|', @patterns2]}){6})" .
'\s*# #\s*';
$line =~ /^$re$/g || return;
my($match1,$match2) = ($+{match1}, $+{match2});
push @digits, $pattern_to_digit_1{$_} for $match1 =~ /(.{7})/g;
push @digits, $pattern_to_digit_2{$_} for $match2 =~ /(.{7})/g;
$sum += (3,1)[$_%2] * $digits[$_] for 0..11;
$sum % 10 ? '' : join '', @digits;
}
my @lines = (
' # # # ## # ## # ## ### ## ### ## #### # # # ## ## # # ## ## ### # ## ## ### # # # ',
' # # # ## ## # #### # # ## # ## # ## # # # ### # ### ## ## ### # # ### ### # # # ',
' # # # # # ### # # # # # # # # # # ## # ## # ## # ## # # #### ### ## # # ',
' # # ## ## ## ## # # # # ### # ## ## # # # ## ## # ### ## ## # # #### ## # # # ',
' # # ### ## # ## ## ### ## # ## # # ## # # ### # ## ## # # ### # ## ## # # # ',
' # # # # ## ## # # # # ## ## # # # # # #### # ## # #### #### # # ## # #### # # ',
' # # # ## ## # # ## ## # ### ## ## # # # # # # # # ### # # ### # # # # # ',
' # # # # ## ## # # ## ## ### # # # # # ### ## ## ### ## ### ### ## # ## ### ## # # ',
' # # ### ## ## # # #### # ## # #### # #### # # # # # ### # # ### # # # ### # # # ',
' # # # #### ## # #### # # ## ## ### #### # # # # ### # ### ### # # ### # # # ### # # ',
);
for my $line (@lines) {
say decode_UPC($line)
// decode_UPC(join '', reverse split '', $line)
// 'Invalid';
}