Strawberry Perl: "out of memory!" - perl

Question

trying to run the following code:
$combs = combinations(\#set,$k);
while (my $c = $combs->next)
{
$nrc=1;
}
Gives me "out of memory!" when I hit Ctrl+C (because its taking too long and it should not) if I pass a set from, for example, (0..450) and numbers to combine ($k) of 6. This issue does not occur with, lets say, a set of 0..45 and $k=6.
Note that the while loop seems to do nothing, in the original script it printed out the combination and incremented a counter that will hold the total number of combinations. But since I was not sure what the problem was, I decided to eliminate that.
I've read the Algorithm:Combinatorics on CPAN and it states that memory usage is minimal, so I don't know what's happening.
I am using Strawberry Perl 32bit on a Windows 10 machine.
Thanks.
--------------------- COMPLETE CODE
#!/usr/bin/perl
use List::MoreUtils "uniq";
use Algorithm::Combinatorics "combinations";
my $argc = $#ARGV+1;
my #set;
if ($argc == 0)
{
print STDERR "Valor minimo de rango: "; # range min
my $minrange = int <STDIN>;
print STDERR "Valor maximo de rango: "; #range max
my $maxrange = int <STDIN>;
#set = uniq sort { $a <=> $b }($minrange...$maxrange);
}
elsif ($argc == 1)
{
open(SETFROMFILE,"<$ARGV[0]") or die "No se puedo abrir el fichero, $!";
chomp(#set = <SETFROMFILE>);
close(SETFROMFILE);
#set = uniq sort { $a <=> $b } #set;
}
else
{
print STDERR "Uso: $0 [file]\n";
exit;
}
my $nrc = 0;
print STDERR "\n";
print STDERR "Numeros a combinar: "; # get subset
my $k = <STDIN>;
if ($k == 0) { exit; }
$combs = combinations(\#set,$k);
print STDERR "\n";
while (my $c = $combs->next)
{
print join(";",#$c) . "\n";
$nrc++;
}
print STDERR "\n";
print STDERR "numero total de combinaciones: $nrc\n";

Answer 1

It works for me.
use strict;
use warnings;
use Algorithm::Combinatorics qw( combinations );
sub show_mem { system('ps', '--no-heading', '-o', 'rss', $$); }
my #set = (0..450);
my $k = 6;
my $count = 0;
#show_mem();
my $combs = combinations(\#set, $k);
#show_mem();
while (my $c = $combs->next) {
++$count;
if (($count % 100_000) == 0) {
print("$count\n");
#show_mem();
}
}
Output:
784
784
100000
776
200000
784
300000
788
400000
776
500000
780
600000
784
700000
768
800000
784
900000
784
1000000
776
...
Of course, it will take forever to go through all C(451, 6) = 11,303,769,578,640 combinations! (We're talking about 251 days on my machine[1].)
(Note that 11,303,769,578,640 is too large for a 32-bit integer. Fortunately, Perl will switching to using a double-precision floating-point number, and those are large enough to hold that all numbers up to and including that one.)
By the way, if you just need the number of combinations, you can use
my $count = 1; $count *= ( #set - $_ + 1 ) / $_ for 1..$k;
How I timed it:
use Algorithm::Combinatorics qw( combinations );
use Time::HiRes qw( time );
my #set = (0..450);
my $k = 6;
my $count = 0;
my $combs = combinations(\#set, $k);
my $s = time;
while (my $c = $combs->next) {
++$count;
last if $count == 1_000_000;
}
my $e = time;
print($e-$s, "\n");

Answer 2

There are 11.1 trillion combinations of six items out of 450. I'm not surprised it ran out of memory!