From 5df7cd60cef6725f8f8c6517af23ccb3d0fbcb4e Mon Sep 17 00:00:00 2001
From: "E. Choroba" <choroba@matfyz.cz>
Date: Fri, 3 Jul 2020 18:44:34 +0200
Subject: Solve 067: Number Combinations & Letter Phone by E. Choroba

---
 challenge-067/e-choroba/perl/ch-1.pl | 19 +++++++++++++++++++
 challenge-067/e-choroba/perl/ch-2.pl | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+)
 create mode 100755 challenge-067/e-choroba/perl/ch-1.pl
 create mode 100755 challenge-067/e-choroba/perl/ch-2.pl

diff --git a/challenge-067/e-choroba/perl/ch-1.pl b/challenge-067/e-choroba/perl/ch-1.pl
new file mode 100755
index 0000000000..0b5c910812
--- /dev/null
+++ b/challenge-067/e-choroba/perl/ch-1.pl
@@ -0,0 +1,19 @@
+#!/usr/bin/perl
+use warnings;
+use strict;
+
+sub combinations {
+    my ($max, $size) = @_;
+    if ($size == 1) {
+        return map [$_], 1 .. $max
+    } else {
+        return map {
+            my @c = @$_;
+            map [@c, $_], $c[-1] + 1 .. $max
+        } combinations($max, $size - 1)
+    }
+}
+
+use Test::More tests => 1;
+is_deeply [combinations(5, 2)],
+    [ [1,2], [1,3], [1,4], [1,5], [2,3], [2,4], [2,5], [3,4], [3,5], [4,5] ];
diff --git a/challenge-067/e-choroba/perl/ch-2.pl b/challenge-067/e-choroba/perl/ch-2.pl
new file mode 100755
index 0000000000..219012e1ac
--- /dev/null
+++ b/challenge-067/e-choroba/perl/ch-2.pl
@@ -0,0 +1,33 @@
+#!/usr/bin/perl
+use warnings;
+use strict;
+
+my %keyboard = (2 => [qw[ a b c   ]],
+                3 => [qw[ d e f   ]],
+                4 => [qw[ g h i   ]],
+                5 => [qw[ j k l   ]],
+                6 => [qw[ m n o   ]],
+                7 => [qw[ p q r s ]],
+                8 => [qw[ t u v   ]],
+                9 => [qw[ w x y z ]]);
+
+sub expand {
+    my (@digits) = @_;
+    if (@digits == 1) {
+        return @{ $keyboard{ $digits[0] } }
+    } else {
+        return map {
+            my $d = $_;
+            map $d . $_, expand(@digits[1 .. $#digits])
+        } @{ $keyboard{ $digits[0] } }
+    }
+}
+
+sub digits2words {
+    my ($number) = @_;
+    return expand(split //, $number)
+}
+
+use Test::More tests => 1;
+is_deeply [digits2words('35')],
+     ["dj", "dk", "dl", "ej", "ek", "el", "fj", "fk", "fl"];
-- 
cgit