cause why not

1 files changed, 39 insertions, 0 deletions

diff --git a/challenge-053/markus-holzer/perl/ch-2.pl b/challenge-053/markus-holzer/perl/ch-2.pl
new file mode 100644
index 0000000000..f2973a3da7
--- /dev/null
+++ b/challenge-053/markus-holzer/perl/ch-2.pl
@@ -0,0 +1,39 @@
+use Modern::Perl;
+use feature qw( signatures postderef switch );
+no warnings qw(experimental);
+
+my %rules = (
+    a => [ 'e', 'i'           ],
+    e => [ 'i'                ],
+    i => [ 'a', 'e', 'o', 'u' ],
+    o => [ 'a', 'u'           ],
+    u => [ 'e', 'o'           ],
+);
+
+main( shift @ARGV || 2 );
+
+sub main( $n )
+{
+    my @r;
+
+    build_str( $_, $n, \@r )
+        for ( sort keys %rules );
+
+    print join "\n", @r;
+}
+
+sub build_str( $current, $n, $result )
+{
+    my $last = substr( $current,  -1 );
+
+    for ( $rules{ $last }->@* )
+    {
+        given ( $current . $_ )
+        {
+            push $result->@*, $_ and next
+                if length($_) == $n;
+
+            build_str( $_, $n, $result );
+        }
+    }
+}
\ No newline at end of file