2 files changed, 27 insertions, 3 deletions
diff --git a/challenge-057/mark-anderson/perl/ch-2.pl b/challenge-057/mark-anderson/perl/ch-2.pl
new file mode 100644
index 0000000000..eb1ffc2f30
--- /dev/null
+++ b/challenge-057/mark-anderson/perl/ch-2.pl
@@ -0,0 +1,22 @@
+#!/usr/bin/env perl
+use Modern::Perl;
+
+my @words = qw/alphabet book carpet cadmium cadeau alpine/;
+
+my @prefixes;
+
+for my $word (@words) {
+    my $length;
+    my $prefix;
+    my @rest = @words;
+
+    do {
+        $length++;
+        $prefix = substr($word, 0, $length); 
+        @rest = grep { /^$prefix/ } @rest; 
+    } while @rest > 1;
+
+    push (@prefixes, $prefix);
+}
+
+say join(", ", @prefixes);
diff --git a/challenge-057/mark-anderson/raku/ch-2.p6 b/challenge-057/mark-anderson/raku/ch-2.p6
index eb203a884b..bff25c9047 100644
--- a/challenge-057/mark-anderson/raku/ch-2.p6
+++ b/challenge-057/mark-anderson/raku/ch-2.p6
@@ -4,13 +4,15 @@ my @words = <alphabet book carpet cadmium cadeau alpine>;
 
 my @prefixes = gather {
     for @words -> $word {
+        my $length;
         my $prefix;
-        my $length = 0;
+        my @rest = @words;
 
         repeat {
             $length++;
-            $prefix = $word.substr(0, $length);
-        } while @words.grep(* ne $word) ~~ / ^ $prefix /; 
+            $prefix = $word.substr(0, $length); 
+            @rest = @rest.grep(/^$prefix/); 
+        } while @rest > 1;
 
         take $prefix;
     }