#!/usr/bin/perl -w
use strict;

my @array = ("11 12","11 13", "9 8 7", "3 4", "11 4") ;
my %gs_grp;
#print join("\n",(@array));

#recording index of the array for each shared number
    my $count =0;
    for my $key (@array){
        my @gs = split(/ /,$key);
        for my $gs(@gs){
               push (@{$gs_grp{$gs}},$count);
        }
        $count++;
    }

#combine index with shared number
    my @sp = @array;
    for my $gs(keys %gs_grp) {
        my @tmp=();
        for my $grp ( @{ $gs_grp{$gs} } ) {
        next if(scalar @{ $gs_grp{$gs} }==1);
        push(@tmp,split(/ /, ($array[$grp])));
            splice(@sp,$grp,"");
        }
        my %duplicate   = map { $_ => 1 } @tmp;
        my @unique = keys %duplicate;
        push(@sp,join(" ",@unique));

    }
    print join("\n", @sp);
    print "\n";
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The output from the above code is Not correct

The output I want is this:

3 4 11 12 13
9 8 7
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Could anyone please help me here? Thanks