#!/usr/bin/perl -w
use strict;
use Data::Dumper;
use List::Compare;

# The hash which I want to filter, which I manually 'ordered'
# according to 2nd element of the array (184..etc), 
# for better visualization

my %hash = (
 'GTGATCTTAGGACAAGGATAGAAATTAA' => ['1','184',7,'GACAAGG'],
 'TGATCTTAGGACAAGGATAGAAATTAAG' => ['1','185',7,'GACAAGG'],
 'GATCTTAGGACAAGGATAGAAATTAAGA' => ['1','186',7,'GACAAGG'],
 'ACAAGGATAGAAATTAAGATGATCGTCA' => ['1','195',7,'ATCGTCA'],
 'CAAGGATAGAAATTAAGATGATCGTCAT' => ['1','196',7,'ATCGTCA'],
 'CAACATGCGATTACGATTACGAGTGGCG' => ['1','240',13,'GATTACG','GATTACG'],
 'AACATGCGATTACGATTACGAGTGGCGC' => ['1','241',13,'GATTACG','GATTACG'],
 'ATGCGATTACGATTACGAGTGGCGCTCG' => ['1','244',20,'GATTACG','GATTACG','GCGCTCG'],
);


my %filtered_hash = filter(%hash);
print Dumper \%filtered_hash;


sub filter
{
        my %hoa = @_;
        my %filtered_hoa;
        my @key = (sort {$hoa{$a}[1] <=> $hoa{$b}[1] } keys %hoa);


        foreach my $key (@key)
        {
            my @submt_only = @{$hoa{$key}}[3..$#{$hoa{$key}}];

            my @flag = @submt_only;

            #Check if the current array is equiv. with *one* before
            my $lc = List::Compare->new(\@flag,\@submt_only);
            my $eq = $lc->is_LeqvlntR;

            if ($eq == 0 )
            {  #if they are not equivalent, assign them to a hash
                $filtered_hoa{$key} = $hoa{$key};
            }
            else
            {   #otherwise skip them
                next;
            }
        }

        return %filtered_hoa;
}

##</code><code>##

my %filtered_hash = (
 'GTGATCTTAGGACAAGGATAGAAATTAA' => ['1','184',7,'GACAAGG'],
 'ACAAGGATAGAAATTAAGATGATCGTCA' => ['1','195',7,'ATCGTCA'],
 'CAACATGCGATTACGATTACGAGTGGCG' => ['1','240',13,'GATTACG','GATTACG'],
 'ATGCGATTACGATTACGAGTGGCGCTCG' => ['1','244',20,'GATTACG','GATTACG','GCGCTCG'],
);