Solution to challenge #1

1 files changed, 43 insertions, 0 deletions

diff --git a/challenge-069/brtastic/perl/ch-1.pl b/challenge-069/brtastic/perl/ch-1.pl
new file mode 100644
index 0000000000..f892b6ad7c
--- /dev/null
+++ b/challenge-069/brtastic/perl/ch-1.pl
@@ -0,0 +1,43 @@
+use v5.32;
+use warnings;
+
+use feature qw(signatures);
+no warnings qw(experimental::signatures);
+
+use constant MIRRORED => {qw(
+	6 9
+	9 6
+	0 0
+	8 8
+)};
+
+my $tr_search = join "", keys MIRRORED->%*;
+my $tr_replace = join "", values MIRRORED->%*;
+
+sub is_strobogrammatic($number = $_) {
+	my sub flip($string) {
+		my $count;
+		eval "\$count = \$string =~ tr/$tr_search/$tr_replace/";
+		return $count == length $string ? scalar reverse $string : undef;
+	}
+
+	my $flipped = flip($number);
+	return !!0 unless defined $flipped;
+	return $number eq $flipped;
+}
+
+sub find_strobogrammatic_in_range($from, $to) {
+	return [
+		grep is_strobogrammatic,
+		grep { /^[$tr_search]+$/ }
+		$from .. $to
+	];
+}
+
+use Test::More;
+
+is_deeply find_strobogrammatic_in_range(50, 100), [69, 88, 96];
+is_deeply find_strobogrammatic_in_range(0, 10), [0, 8];
+is_deeply find_strobogrammatic_in_range(100, 1000), [609, 689, 808, 888, 906, 986];
+
+done_testing;