#!/usr/bin/perl

use strict;
use Algorithm::Loops qw(NestedLoops);

  my ($rs_ref,$key,$value,$sum,$count,%matches);
  my $amount = 16;
  my $depth = 6;

  $rs_ref->{'A'}->{'amount'} = 10;
  $rs_ref->{'B'}->{'amount'} = 5;
  $rs_ref->{'C'}->{'amount'} = 13;
  $rs_ref->{'D'}->{'amount'} = 3;
  $rs_ref->{'E'}->{'amount'} = 15;
  $rs_ref->{'F'}->{'amount'} = 1;

  my $start_time = time();

  $count = NestedLoops(
    [ ( [keys %{$rs_ref}] ) x $depth ],
    { OnlyWhen => sub {
        @_ == keys %{{@_,reverse@_}};
      }
    },
    sub {
      $sum = 0;
      foreach $key(@_) {
        $value = $rs_ref->{$key}->{'amount'};
        $sum += $value;
      }
      if ($sum == $amount) {
        $matches{join ' ', sort { $a cmp $b} @_} = 1;
      }
    },
  );

  print "Searched $count combinations...\n";

  foreach $key (keys %matches) {
    print "MATCH: $key\n";
  }

  my $end_time = time();

  print "Finished in " . ($end_time - $start_time)/60 . " minutes.\n";