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

use Data::Dumper;

my @list = (1 .. 5);
my $take = 2;

my @combs = comb_integral(\@list, $take);
for my $comb (@combs) {
  print "@$comb\n";
}

sub comb_integral {
  my ($items, $group, $next) = @_;
  $next ||= 0;

  if ($group == 1) {
    return map [$_], @$items[$next..$#$items];
  } else {
    my @returns;
    for my $i ($next..$#$items) {
      push @returns, map [$$items[$i], @$_], comb_integral($items, $group - 1, $i + 1);
    }
    return @returns;
  }
}