add solution week 135 task 2 in perl

1 files changed, 43 insertions, 0 deletions

diff --git a/challenge-135/steven-wilson/perl/ch-2.pl b/challenge-135/steven-wilson/perl/ch-2.pl
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+++ b/challenge-135/steven-wilson/perl/ch-2.pl
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+#!/usr/bin/env perl
+# Week 135 Task 2
+# Validate SEDOL
+
+use strict;
+use warnings;
+use feature qw/ say /;
+use Test::More;
+use Test::Exception;
+
+ok( validate_sedol('2936921') == 1, "Valid SEDOL" );
+ok( validate_sedol('1234567') == 0, "Invalid SEDOL" );
+ok( validate_sedol('B0YBKL9') == 1, "Valid SEDOL" );
+dies_ok { validate_sedol('B0YBKLA'), } 'Die when check digit not a digit';
+dies_ok { validate_sedol('B0YBKLF9'), } "Die when SEDOL not correct length";
+dies_ok { validate_sedol('#0YDK29'), } "Die when invalid character";
+done_testing();
+
+sub validate_sedol {
+    my $input = shift;
+    length $input == 7 or die "Invalid SEDOL number, not correct length\n";
+    my $code  = substr $input, 0, 6;
+    my $check = substr $input, 6, 1;
+    $check =~ /[0-9]/ or die "Invalid SEDOL number, invalid check digit\n";
+    $check == get_sedol_check_digit($code);
+}
+
+sub get_sedol_check_digit {
+    my $code   = shift;
+    my @weight = qw/ 1 3 1 7 3 9 1 /;
+    $code =~ /[0-9A-Z]{6}/ or die "Invalid SEDOL number, invalid character\n";
+    my @code = split //, $code;
+    my $sum  = 0;
+    for ( my $i = 0; $i < 6; $i++ ) {
+        if ( ord( $code[$i] ) < 58 ) {
+            $sum += ( $code[$i] * $weight[$i] );
+        }
+        else {
+            $sum += ( ( ord( $code[$i] ) - 64 + 9 ) * $weight[$i] );
+        }
+    }
+    return ( ( 10 - ( $sum % 10 ) ) % 10 );
+}