To compare any two groups, you'd do something like: 
sub is_ok
{
    my ($x, $y) = @_;
    my (%x, %y);

    @x{@$x} = 1;
    @y{@$y} = 1;

    foreach my $k (keys %x)
    {
        return 0 if exists $y{$k};
    }

    return 1;
}

[download]
Put in a loop, as necessary. Lather, rinse, repeat. A few notes:
  1. This will work with groups of arbitrary size and will also work with groups of different sizes.
  2. It will also work with groups that contain arbitrary data.
  3. It will throw warnings if any of the elements are undef.
  4. It does string comparisons, so 2, 4, 6 and 1.0, 2.0, 3.0 may or may not be ok. I will leave numeric comparisons as an exercise for the reader.

------
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Don't go borrowing trouble. For programmers, this means Worry only about what you need to implement.

Please remember that I'm crufty and crochety. All opinions are purely mine and all code is untested, unless otherwise specified.

In reply to Re: Pair of items by dragonchild
in thread Pair of items by artist

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