#!/usr/bin/perl --

use strict;
use warnings;


my(@list ) = sort qw[
abcpwbln08
abcpwbln07
abcpwbnn10
abcpwbnn06

adesicln09
adesicln08
adesicln01
adesicnn05

];

use Data::Dumper;

my $len = length 'abcpwbnn';
my $ret = floyd( \@list, $len, ) ;
print Dumper($ret),"\n";

for my $ar( @$ret ){
    if($#{$ar} > 0){
        print substr $ar->[0], 0, $len;
        print "*\n";
    } else {
        print $ar->[0],"\n";
    }
}


sub floyd
{
    my ( $input, $len ) = @_;
    my %output;
    keys %output = scalar @$input; #presize %output, max possible
    my @keys;
    my $num_keys_l = 0;
    for my $i( @$input ){
        my $ikey = substr $i, 0, $len;
        push @{$output{$ikey}}, $i;
        my $nkeys = 0+ keys %output;
        if( $nkeys > $num_keys_l ){
            $num_keys_l = $nkeys;
            push @keys, $ikey;
        }
    }
    return [ @output{@keys} ];
}


__END__
$VAR1 = [
          [
            'abcpwbln07',
            'abcpwbln08'
          ],
          [
            'abcpwbnn06',
            'abcpwbnn10'
          ],
          [
            'adesicln01',
            'adesicln08',
            'adesicln09'
          ],
          [
            'adesicnn05'
          ]
        ];

abcpwbln*
abcpwbnn*
adesicln*
adesicnn05
[download]