#!/usr/bin/perl
use strict;
use warnings 'all';
use Data::Dumper;

my @found = ("10\tdomain-a", "12\tdomain-b", "5\tdomain-c",
             "8\tdomain-a",  "14\tdomain-b", "15\tdomain-c",
             "11\tdomain-a", "13\tdomain-b", "10\tdomain-c");

# get doubles
my %seen;
foreach my$i (0..$#found) {
    my @ele = split("\t", $found[$i]);
    $seen{$ele[-1]} = [] unless $seen{$ele[-1]};
    push(@{$seen{$ele[-1]}}, [$i, $ele[0]]);
}

# delete doubles
foreach my$key (keys %seen) {
    if (@{$seen{$key}} > 1) {
        # sort
        my $top = $seen{$key}->[0];
        foreach my$act (@{$seen{$key}})
        { if ($act->[1] > $top->[1]) { $top = $act } }

        # splice
        foreach my$act (@{$seen{$key}})
        { if ($act->[0] != $top->[0]) { $found[$act->[0]] = undef } }
    }
}
@found = grep { defined($_) } @found;

# output
print "\@FOUND:\n", Dumper(\@found), "\n";