my %hash = map {$gp1[$_] => $gp2[$_]} 0 .. $#gp1;

#13488050:c183911-182727     57165207:6809301-6810488

##</code><code>##


foreach my $line (@blast)       {
        if ($line =~ /gi\|(\d+.{1,2}\d+\-.{0,1}\d+)\s+gi\|(\d+.{1,2}\d+\-.{0,1}\d+)\s+(\d{0,2}.{0,2}\d{0,2}.{0,2}\d{0,3})\s+\d+\s+(\d+.{0,3}\d+)\s+\d+\s+\d+\s+\d+\/\d+\s+(\d+)/)       {
                ###print "$1\t$2\t$5\n";
                my $n1 = $1;
                push @id1, "$1 ";
                push @id2, "$2 ";
                push @percent_id, "$5 ";
             
                # need to here check whether $1 eq key and $2 eq value but am stuck!

  }
}