use strict;
use warnings;

use Math::Combinatorics qw( permute );
use Test::More;

my @match_wanted = qw( abc bca cab cba bac acb );
my @match_unwanted = qw( aab abbc acc );
my @charset = qw( a b c );

my %valid = map { join( '', @$_ ) => 1 } permute( @charset );

sub match
{
    my $s = shift;
    return( exists $valid{$s} ? 1 : 0 );
}

plan 'tests' => ( scalar @match_wanted + scalar @match_unwanted );

ok(   match( $_ ), "matches '$_'" )        for @match_wanted;
ok( ! match( $_ ), "does not match '$_'" ) for @match_unwanted;

##</code><code>##

1..9
ok 1 - matches 'abc'
ok 2 - matches 'bca'
ok 3 - matches 'cab'
ok 4 - matches 'cba'
ok 5 - matches 'bac'
ok 6 - matches 'acb'
ok 7 - does not match 'aab'
ok 8 - does not match 'abbc'
ok 9 - does not match 'acc'