Raymond Hettinger <[EMAIL PROTECTED]> wrote: > [EMAIL PROTECTED] ]
>>> OK, so I need to be more precise. >>> Given a list of sets, output the largest list of sets (from this list, >>> order does not matter) such that: >>> 1) there is no set that is a PROPER subset of another set in this list >>> 2) no two sets have exactly the same members (100% overlap) > [Bengt Richter] >> two from the above come out length 5: > With multiple outputs satisfying the constraints, I would suspect > that there is something wrong with the original spec (not as a > stand-alone problem, but as component of a real application). I don't know what the application is trying to do, but if I understand it correctly, he is asking for something called a "maximal anti-chain". For any partial order (e.g., subset relation), a chain is a set of elements which are all comparable (and hence there is a linear or total order on this set). In a similar way, an anti-chain is a set of elements consisting of elements that are incomparable to each other. Anti-chains themselves can be ordered by subset inclusion, and thefore maximal ("largest") anti-chains can be found, but in general there is no unique "greatest" anti-chain. So the spec is perfectly ok and makes a lot of sense mathematically, it's just that there is no unique solution. Maybe googling for "maximal anti-chain" digs up some more information (I haven't tried). - Dirk -- http://mail.python.org/mailman/listinfo/python-list