UPC: Difference between revisions

=={{header|Perl}}==

{{trans|Perl 6}}

<lang perl>use strict;

use warnings;

use feature 'say';

sub decode_UPC {

my($line) = @_;

my(%pattern_to_digit_1,%pattern_to_digit_2,@digits,$sum);

my @patterns1 = (' ## #', ' ## #', ' # ##', ' #### #', ' # ##',

' ## #', ' # ####', ' ### ##', ' ## ###', ' # ##');

my @patterns2 = @patterns1;

$patterns2[$_] =~ tr/# / #/ for 0..$#patterns2;

$pattern_to_digit_1{$patterns1[$_]} = $_ for 0..$#patterns1;

$pattern_to_digit_2{$patterns2[$_]} = $_ for 0..$#patterns2;

my $re = '\s*# #\s*((?:' . join('|',@patterns1) . '){6})\s*# #\s*((?:' . join('|',@patterns2) . '){6})\s*# #\s*';

$line =~ /^$re$/g || return;

my($match1,$match2) = ($1,$2);

push @digits, $pattern_to_digit_1{$_} for $match1 =~ /(.......)/g;

push @digits, $pattern_to_digit_2{$_} for $match2 =~ /(.......)/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';

}

</lang>

{{out}}

<pre>924773271019

403944441050

834999676706

939825158811

Invalid

316313718717

214575875608

818778841813

706466743030

653483540435</pre>