another solution

1 files changed, 37 insertions, 0 deletions

diff --git a/LEXV.pl b/LEXV.pl
new file mode 100644
index 0000000..e19a913
--- /dev/null
+++ b/LEXV.pl
@@ -0,0 +1,37 @@
+#!/usr/bin/env perl
+use strict;
+use warnings;
+use 5.016;
+
+my @string = split ' ', scalar(<>);
+chomp(my $length = <>);
+
+unshift @string, undef;
+my $base = @string;
+
+for my $num (0..$base ** $length - 1) {
+    my @digits;
+    my $remainder = $num;
+    for my $digit (1..$length) {
+        my $exponent = $length - $digit;
+        push @digits, int($remainder / $base ** $exponent);
+        $remainder -= $digits[-1] * $base ** $exponent;
+    }
+    @digits = map { $string[$_] } @digits;
+    next unless valid(@digits);
+    say join('', grep { defined } @digits);
+}
+
+sub valid {
+    my @digits = @_;
+
+    return unless grep { defined } @digits;
+
+    my $seen_undef;
+    for my $digit (@digits) {
+        return if $seen_undef && defined($digit);
+        $seen_undef = 1 if !defined($digit);
+    }
+
+    return 1;
+}