#!/usr/lib/perl
use strict;
use warnings;

my $kPoolSize = 2;
my %hash = (
    3 => [ 1 .. 2 ],
    4 => [ 2 .. 2 ],
    6 => [ 4 .. 5 ],
    7 => [ 2 .. 6 ],
    8 => [ 1 .. 3 ],
   11 => [ 5 .. 10 ],
);
my @indexes = sort {$a <=> $b} keys %hash;
my @pool = splice @indexes, 0, $kPoolSize;

while (@pool == $kPoolSize) {
    my $poolSum;
    
    for my $poolEntry (@pool) {
        $poolSum += $_ for @{$hash{$poolEntry}};
    }
    
    print "Pool @pool sum: $poolSum\n";
    shift @pool;
    push @pool, shift @indexes if @indexes;
}