#!/bin/perl

=pod

The Weekly Challenge - 277
- https://theweeklychallenge.org/blog/perl-weekly-challenge-277

Author: Niels 'PerlBoy' van Dijke

Task 1: Count Common
Submitted by: Mohammad Sajid Anwar

You are given two array of strings, @words1 and @words2.

Write a script to return the count of words that appears in both
arrays exactly once.

=cut

use v5.32;
use feature qw(signatures);
use common::sense;

use Test2::V0 qw(-no_srand);

use List::AllUtils qw(singleton);

sub countCommon {
  my %f;
  $f{$_}++ for (singleton(@{$_[0]}),singleton(@{$_[1]}));
  grep { $_ == 2 } values %f;
}

is(countCommon([qw{Perl is my friend}],
               [qw{Perl and Raku are friend}]),2);
is(countCommon([qw{Perl and Python are very similar}],
               [qw{Python is top in guest languages}]),1);
is(countCommon([qw{Perl is imperative Lisp is functional}],
               [qw{Crystal is similar to Ruby}]),0);

done_testing;