- Added solution by Pete Houston.

2 files changed, 54 insertions, 0 deletions

diff --git a/challenge-057/pete-houston/perl/5702.pm b/challenge-057/pete-houston/perl/5702.pm
new file mode 100644
index 0000000000..3985383f6a
--- /dev/null
+++ b/challenge-057/pete-houston/perl/5702.pm
@@ -0,0 +1,43 @@
+#!/usr/bin/env perl
+use strict;
+use warnings;
+ 
+main () unless caller;
+
+sub shortest_prefs {
+	my $wordlist = shift;
+	my $prefcounts = prefcounts (@$wordlist);
+	return [ map { minpref ($_, $prefcounts) } @$wordlist ];
+}
+
+sub prefcounts {
+	my @wordlist = @_;
+	my %counts;
+	for my $word (@wordlist) {
+		while (length ($word)) {
+			$counts{$word}++;
+			$word =~ s/.$//;
+		}
+	}
+	return \%counts;
+}
+
+sub minpref {
+	my ($word, $counts) = @_;
+	for my $i (1 .. length ($word)) {
+		my $pref = substr $word, 0, $i;
+		return $pref if $counts->{$pref} == 1;
+	}
+	return ''; # If non-unique
+}
+
+sub aref_from_argv {
+	# Sanitise input format
+	my @in = map { s/[",]//g; $_ } grep { ! /^[[\]]$/ } @ARGV;
+	return \@in;
+}
+
+sub main {
+	my $out = shortest_prefs (aref_from_argv ());
+	print '[ ', join (', ', map { qq{"$_"} } @$out), " ]\n";
+}
\ No newline at end of file
diff --git a/challenge-057/pete-houston/perl/ch-2.pl b/challenge-057/pete-houston/perl/ch-2.pl
new file mode 100644
index 0000000000..3d0aa24ea6
--- /dev/null
+++ b/challenge-057/pete-houston/perl/ch-2.pl
@@ -0,0 +1,11 @@
+use strict;
+use warnings;
+
+use Test::More tests => 1;
+use lib '.';
+require '5702.pm';
+
+my $in = [ "alphabet", "book", "carpet", "cadmium", "cadeau", "alpine" ];
+my $want = [ "alph", "b", "car", "cadm", "cade", "alpi" ];
+
+is_deeply shortest_prefs ($in), $want;