#!/usr/bin/perl
use Benchmark;
my $count = 100;
 
my $end = 30;
sub ref {
  my $a = [1];
 
  for(1..$end){
#    print "@$a\n";
 
    my @na;
    ($na[-1] == $_ ? $na[-2]++ : push @na, (1, $_)) for @$a;
    $a = \@na;
  }
}
 
sub no_ref {
  my @a = (1);
 
  my @na;
  for (1..$end){
#    print "@a\n";
 
    @na = ();
    ($na[-1] == $_ ? $na[-2]++ : push @na, (1, $_)) for @a;
 
    @a = @na;
  }
}
timethese($count, { 'no_ref' => \&no_ref , 'ref' => \&ref} );