Create ch-1.pl

1 files changed, 23 insertions, 0 deletions

diff --git a/challenge-199/james-smith/perl/ch-1.pl b/challenge-199/james-smith/perl/ch-1.pl
new file mode 100644
index 0000000000..2dbeb6a090
--- /dev/null
+++ b/challenge-199/james-smith/perl/ch-1.pl
@@ -0,0 +1,23 @@
+#!/usr/local/bin/perl
+
+use strict;
+use warnings;
+use feature qw(say);
+use Test::More;
+use Benchmark qw(cmpthese timethis);
+
+my @TESTS = (
+  [ [1,2,3,1,1,3],4 ],
+  [ [1,2,3],      0 ],
+  [ [1,1,1,1],    6 ],
+);
+
+is( good_pairs(@{$_->[0]}), $_->[1] ) foreach @TESTS;
+
+sub good_pairs {
+  my($c,%f);
+  $f{$_}++ for @_;
+  $c+=$_*($_-1) for values %f;
+  $c/2;
+}
+done_testing();