Select Code to Download

Use a hash. Here's code to do both and more. It assumes that each elem
+ent is unique in a given array:

...
        push @{ $count{$element} > 1 ? \@intersection : \@difference }
+, $element;
    }
Note that this is the symmetric difference, that is, all elements in e
+ither A or in B but not in both. Think of it as an xor operation.

$_=$,=q,\,@4O,,s,^$,$\,,s,s,^,b9,s,
$_^=q,$\^-]!,,print