my %array2 = map(($_ => undef), @array2);
my @delete;

# Traverse array1
foreach (@array1) {
    exists $array2{$_} && push(@delete, $_);
}

my %array1 = map(($_ => undef), @array1);
my @add;

# Traverse array2
foreach (@array2) {
    exists $array1{$_} && push(@add, $_);
}