Added initial files for challenge 089.

Added README for first commit.
Created initial script for challenge 1 using binary GCD algorithm.

2 files changed, 64 insertions, 0 deletions

diff --git a/challenge-089/jcrosswh/README b/challenge-089/jcrosswh/README
new file mode 100644
index 0000000000..144afd1a18
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+++ b/challenge-089/jcrosswh/README
@@ -0,0 +1 @@
+Solution by Joel Crosswhite.
\ No newline at end of file
diff --git a/challenge-089/jcrosswh/perl/ch-1.pl b/challenge-089/jcrosswh/perl/ch-1.pl
new file mode 100644
index 0000000000..ff0f0979a0
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+++ b/challenge-089/jcrosswh/perl/ch-1.pl
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+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+
+=head1 NAME
+
+PWC 089 Challenge 1
+
+=head1 SYNOPSIS
+
+  $ ch-1.pl 3
+  3
+  
+  $ ch-1.pl 4
+  7
+
+=head1 DESCRIPTION
+
+Given a positive integer, this script will sum the
+L<GCD|https://en.wikipedia.org/wiki/Greatest_common_divisor> of all possible
+unique pairs between 1 and the inputed positive integer.
+
+=head1 AUTHORS
+
+Joel Crosswhite E<lt>joel.crosswhite@ix.netcom.comE<gt>
+
+=cut
+
+my $input = $ARGV[0];
+if (!defined($input) || $input !~ m/^[1-9]\d*$/) {
+    print "Usage: ch-1.pl <positive integer>\n";
+    exit 1;
+}
+
+my $retval = 0;
+for (my $i = 1; $i < $input; $i++) {
+    for (my $k = $i + 1; $k <= $input; $k++) {
+        $retval += gcd($i, $k);
+    }
+}
+
+print $retval . "\n";
+exit 0;
+
+sub gcd {
+    my ($first, $second, $d) = @_;
+    $d = 0 if !defined($d);
+    
+    if ($first == $second) {
+        return $first * 2 ** $d;
+    } elsif ($first % 2 == 0 && $second % 2 == 0) {
+        return gcd($first / 2, $second / 2, $d + 1);
+    } elsif ($first % 2 == 0) {
+        return gcd($first / 2, $second, $d);
+    } elsif ($second % 2 ==0) {
+        return gcd($first, $second / 2, $d);
+    } else {
+        my $c = abs($first - $second);
+        my $new_second = $first < $second ? $first : $second;
+        return gcd($c / 2, $new_second, $d);
+    }
+}# gcd