This may help you. The code below generates a array list that eliminates redundant data.

my @set = qw(A B C D A);

my @list;

my $elm;

my $count=0;

foreach my $one (@set) {

foreach my $two (@set) {

$elm ="$one"."$two";

foreach $list(@list){$count++ if ($list eq elm);}

push @list,"$one$two" if($count eq 0);

}

}

Cheers!!!!

Anandatirtha