sgreen solutions to challenge 135

4 files changed, 68 insertions, 2 deletions

diff --git a/challenge-135/sgreen/README.md b/challenge-135/sgreen/README.md
index 298af3387e..12939a8bf5 100644
--- a/challenge-135/sgreen/README.md
+++ b/challenge-135/sgreen/README.md
@@ -1,3 +1,3 @@
-# The Weekly Challenge 133
+# The Weekly Challenge 135
 
-Solution by Simon Green. [Blog](https://dev.to/simongreennet/weekly-challenge-133-7gi)
+Solution by Simon Green. [Blog](https://dev.to/simongreennet/weekly-challenge-135-g0o)
diff --git a/challenge-135/sgreen/blog.txt b/challenge-135/sgreen/blog.txt
new file mode 100644
index 0000000000..5f1dbb024e
--- /dev/null
+++ b/challenge-135/sgreen/blog.txt
@@ -0,0 +1 @@
+https://dev.to/simongreennet/weekly-challenge-135-g0o
diff --git a/challenge-135/sgreen/perl/ch-1.pl b/challenge-135/sgreen/perl/ch-1.pl
new file mode 100755
index 0000000000..e667b28205
--- /dev/null
+++ b/challenge-135/sgreen/perl/ch-1.pl
@@ -0,0 +1,24 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use feature 'say';
+
+sub main {
+    my $n = shift;
+
+    # Check the input is valid
+    die "You must enter an integer\n"               unless $n;
+    die "The input does not look like an integer\n" unless $n =~ /^-?[1-9][0-9]*$/;
+
+    # If it's a negative number, treat it like a positive from now onwards
+    $n = abs($n);
+    my $l = length( $n // '' );
+    die "even numbers of digits\n" unless $l % 2 == 1;
+    die "too short\n"              unless $l >= 3;
+
+    # Display the middle three digits
+    say substr( $n, ( $l - 3 ) / 2, 3 );
+}
+
+main(@ARGV);
diff --git a/challenge-135/sgreen/perl/ch-2.pl b/challenge-135/sgreen/perl/ch-2.pl
new file mode 100755
index 0000000000..1b0e850aeb
--- /dev/null
+++ b/challenge-135/sgreen/perl/ch-2.pl
@@ -0,0 +1,41 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use feature 'say';
+
+sub _is_sedol {
+    my $input  = shift;
+    my @weight = qw(1 3 1 7 3 9 1);
+
+    # Check that valid characters are used. The first six
+    #  characters are letters (not vowels) or numbers. The last
+    #  character must be a digit.
+    return 0 unless $input =~ /^[B-DF-HJ-NP-TV-Z0-9]{6}[0-9]$/;
+
+    # Start with the last digit
+    my $sum = substr( $input, 6 );
+    for my $i ( 0 .. 5 ) {
+        # Get the character, and work out its value.
+        my $c = substr( $input, $i, 1 );
+        my $v = $c =~ /[0-9]/ ? $c : ord($c) - 55;
+
+        # Add the value to the sum multiplied by the weight
+        $sum += $v * $weight[$i];
+    }
+
+    # This is a SEDOL value if it ends in a zero
+    return $sum % 10 ? 0 : 1;
+}
+
+sub main {
+    my $input = shift;
+
+    # Sanity check
+    die "You must enter a value\n"             unless defined $input;
+    die "The value must be seven characters\n" unless length($input) == 7;
+
+    say _is_sedol($input);
+}
+
+main(@ARGV);