use List::MoreUtils qw/any/;

my @a = ( 1, 2, 3 );
my @b = ( 2, 3, 1 );
my @c = ( 1, 2, 4 );

print "(@a) and (@b) are equal sets.\n" if identical( \@a, \@b );
print "(@a) and (@c) are equal sets.\n" if identical( \@a, \@c );
print "(@b) and (@c) are equal sets.\n" if identical( \@b, \@c );

sub identical {
    my( $left, $right ) = @_;
    return 0 if scalar @$left != scalar @$right;
    my( %bag );
    $bag{$_}++  for @$left;
    $bag{$_}-- for @$right;
    return 0 if any{ $bag{$_} } keys %bag;
    return 1;
}