Problem 43, Perl 5.

043.pl

@@ -0,0 +1,67 @@
+#!/usr/bin/env perl
+use strict;
+use warnings;
+use 5.010;
+use List::MoreUtils qw(uniq);
+
+sub is_pandigital {
+    my ($n) = @_;
+
+    foreach my $d ( 0 .. 9 ) {
+        return 0 unless $n =~ /$d/;
+    }
+
+    return 1;
+}
+
+sub has_unique_digits {
+    my ($n) = @_;
+
+    my @d = split( //, $n );
+
+    return scalar @d == scalar uniq @d;
+}
+
+sub chains {
+    my ( $n, @chunks ) = @_;
+
+    return ($n) unless @chunks;
+
+    my $head = substr( $n, 0, 2 );
+    my $end = pop @chunks;
+    my @chains;
+    foreach my $e (@$end) {
+        if ( $head eq substr( $e, 1, 2 ) ) {
+            push @chains, chains( substr( $e, 0, 1 ) . $n, @chunks );
+        }
+    }
+    return @chains;
+}
+
+my @divisors = qw(2 3 5 7 11 13 17);
+my @chunks;
+foreach my $d (@divisors) {
+    my @c;
+    my $n = 0;
+    while ( ( my $c = sprintf( '%03d', $d * $n ) ) < 1000 ) {
+        if ( has_unique_digits($c) ) {
+            push @c, $c;
+        }
+        $n++;
+    }
+    push @chunks, \@c;
+}
+
+my $sum;
+my $end = pop @chunks;
+foreach my $x (@$end) {
+    foreach my $n ( chains( $x, @chunks ) ) {
+        foreach my $a ( 1 .. 9 ) {
+            my $b = $a . $n;
+            if ( is_pandigital($b) ) {
+                $sum += $b;
+            }
+        }
+    }
+}
+say $sum;