From 714f4b0fdf3eb48eafd1ed22dcb6a8be26b69827 Mon Sep 17 00:00:00 2001
From: Simon Green <mail@simon.green>
Date: Thu, 4 Mar 2021 22:20:15 +1000
Subject: sgreen solution to challenge 102

---
 challenge-102/sgreen/README.md    |  4 ++--
 challenge-102/sgreen/blog.txt     |  1 +
 challenge-102/sgreen/perl/ch-1.pl | 39 +++++++++++++++++++++++++++++++++++++++
 challenge-102/sgreen/perl/ch-2.pl | 26 ++++++++++++++++++++++++++
 4 files changed, 68 insertions(+), 2 deletions(-)
 create mode 100644 challenge-102/sgreen/blog.txt
 create mode 100755 challenge-102/sgreen/perl/ch-1.pl
 create mode 100755 challenge-102/sgreen/perl/ch-2.pl

diff --git a/challenge-102/sgreen/README.md b/challenge-102/sgreen/README.md
index 92b3149288..6fb5a4942c 100644
--- a/challenge-102/sgreen/README.md
+++ b/challenge-102/sgreen/README.md
@@ -1,3 +1,3 @@
-# The Weekly Challenge 101
+# The Weekly Challenge 102
 
-Solution by Simon Green. [Blog](https://dev.to/simongreennet/weekly-challenge-101-jeo)
+Solution by Simon Green. [Blog](https://dev.to/simongreennet/weekly-challenge-102-57jb)
diff --git a/challenge-102/sgreen/blog.txt b/challenge-102/sgreen/blog.txt
new file mode 100644
index 0000000000..b2ec98e7ea
--- /dev/null
+++ b/challenge-102/sgreen/blog.txt
@@ -0,0 +1 @@
+https://dev.to/simongreennet/weekly-challenge-102-57jb
diff --git a/challenge-102/sgreen/perl/ch-1.pl b/challenge-102/sgreen/perl/ch-1.pl
new file mode 100755
index 0000000000..01611cfee7
--- /dev/null
+++ b/challenge-102/sgreen/perl/ch-1.pl
@@ -0,0 +1,39 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use feature 'say';
+
+sub main {
+    my $length = shift;
+
+    # Sanity check
+    die "You must specify a number\n" if not defined $length;
+    die "The number is not a positive integer\n" unless $length =~ /^[1-9][0-9]*$/;
+
+    # Build a hash table with all the possible squares
+    my %squares = ();
+    my $counter = 0;
+    while ( $counter**2 < 2 * 10**$length ) {
+        ++$counter;
+        $squares{ $counter**2 } = $counter;
+    }
+
+    my @solutions = ();
+    my $r         = 10**( $length - 1 );
+    while ( $r < 10**$length ) {
+        my $r1 = reverse($r);
+        push @solutions, $r if ( $r >= $r1 and $squares{ $r - $r1 } and $squares{ $r + $r1 } );
+        ++$r;
+    }
+
+    if ( scalar(@solutions) ) {
+        say join ' ', @solutions;
+    }
+    else {
+        say 'No solutions found';
+    }
+}
+
+main(@ARGV);
+
diff --git a/challenge-102/sgreen/perl/ch-2.pl b/challenge-102/sgreen/perl/ch-2.pl
new file mode 100755
index 0000000000..bb68d3ab49
--- /dev/null
+++ b/challenge-102/sgreen/perl/ch-2.pl
@@ -0,0 +1,26 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use feature 'say';
+
+sub main {
+    my $length = shift;
+
+    # Sanity check
+    die "You must specify a number\n" if not defined $length;
+    die "The number is not a positive integer\n" unless $length =~ /^[1-9][0-9]*$/;
+
+    my $string   = '#' x $length;
+    my $position = $length - 1;     # The last character
+
+    while ( $position - length( $position + 1 ) >= 0 ) {
+        my $char = length( $position + 1 );
+        substr( $string, $position - $char, $char, $position + 1 );
+        $position -= ( $char + 1 );
+    }
+
+    say $string;
+}
+
+main(@ARGV);
-- 
cgit