#!/usr/bin/perl
use Benchmark "cmpthese";

my $len      = shift @ARGV || 12;
my $max_reps = shift @ARGV || 2;

sub almut {
    my @set = qw( A B C D E F );
    for (1..100) {
        my $result = '';
        while (length($result) < $len) {
             my $char = $set[ rand @set ];
             next if substr($result, -$max_reps) eq $char x $max_reps;
             $result .= $char;
        }
    }
}

sub salva {
    my $set = [ qw( A B C D E F ) ];
    for (1..100) {
        my $out = '';
        my $last_ix = -1;
        my $reps = 0;
        for (1..$len) {
          my $ix;
          if ($reps >= $max_reps) {
            $ix = int rand(@$set - 1);
            $ix++ if $ix >= $last_ix;
          }
          else {
            $ix = int rand(@$set);
          }
          if ($ix == $last_ix) {
            $reps++;
          }
          else {
            $last_ix = $ix;
            $reps = 1;
          }
          $out .= $set->[$ix];
        }
    }
}

cmpthese(-1, {
    almut => \&almut,
    salva => \&salva,
});