my @arrays = ([...], [...], [...]);
my %tmp_int;

# assume intersection is entirety of first array
# and set each "frequency" to the number of arrays
@tmp_int{@{ $arrays[0] }) = (@arrays+0) x @{ $arrays[0] };

# then check the other arrays against it
for my $set (@arrays[1..$#arrays]) {
  my %seen;
  $tmp_int{$_}-- for grep { !$seen{$_} } @$set;
}

# the ACTUAL intersection is all the
# keys in the hash whose value is 1
my @intersection = grep { $tmp_int{$_} == 1 } keys %tmp_int;