So it looks like you're shifting the highest bit up by one, then the next highest bit, then the next, until you've run out of empty bits. How about something like (untested): 

  use Bit::Vector;

  my $joins  = 2;
  my $splits = 3;
  my $length = $joins+$splits;
  my $start  = '0'x$joins . '1'x$splits;

  my $vector = Bit::Vector->new_Bin($length, $start);
  my @combinations = ();

  for my $pos ($joins-1..$length-1) { # 0-based, right?
    for my $bit ($splits-1..0) {
      $vector->bit_flip($pos+$bit);
      $vector->bit_flip($pos+$bit-1);
      push @combinations, $vector->to_Bin();
    }
  }

[download]

--
The hell with paco, vote for Erudil!
:wq

In reply to Re(3): Puzzle: need a more general algorithm by FoxtrotUniform
in thread Puzzle: need a more general algorithm by Ovid

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