Permutations and derangements

4 Responses to Permutations and derangements

1. Anonymous says:

   2005/04/04 at 20:42

   I think you meant “the total number of derangements is 44”. You have 4, not 44.
2. Gustavo Niemeyer says:

   2005/04/06 at 14:43

   Right! Thanks!
3. Anonymous says:

   2005/04/07 at 06:35

   hi, I really like your algorithm. did you come up with this yourself or is it based on some permutation theorem?
4. Gustavo Niemeyer says:

   2005/04/07 at 11:06

   It’s my own child. :-)

   The original intent was not producing only permutation sets, but all possible contained groups and order of elements on the given list (e.g. [1,2,3] would also produce [2,3], [3,2], [3], etc). To achieve that just remove the constraint on the queue size before yielding the value.