Cool, I've checked your code and it's not zero suppressed BDDs, although it might not be a performance gain if you used ZDDs. (zero supressed BDDs are very good

Cool, I've checked your code and it's not zero suppressed BDDs, although it might not be a performance gain if you used ZDDs. (zero supressed BDDs are very good at representing sets of permutations/combinations etc. but as far as I understand you have all the possible permutations encoded in the BDD, not a subset of all possible permutations).