On 09.12.2013 14:25, Chris Angelico wrote: >> I found this puzzle again and was thinking about: How would I code a >> brute-force approach to this problem in Python? > > Ooooh interesting!
Ha, I thought so too :-) > Well, here's a start: There's no value in combining the same value in > an AND or an OR, ergo every gate you add must bring together two > different values. > > To start with, you have three values (the three inputs). Every time > you combine two of them, with either type of gate, you create a new > value. You can also combine a single value with a NOT to create its > inverse, but only if you have done so no more than once. > > The goal is to produce something which is provably the opposite of > each of the three inputs. > > I'm not sure if this helps or not, but one thing I learned from > geometry is that setting down everything you know and need to know is > a good basis for the search! Absolutely. > > The hardest part, so far, is proving a result. The algorithm that's > coming to mind is this: > > def find_solution(inputs, not_count): > # TODO: First, see if inputs contains three values that are the inverses > of > # the three values i1,i2,i3. If they are, throw something, that's probably > # the easiest way to unwind the stack. > if not_count < 2: > for val in inputs: > find_solution(inputs + [not val], not_count + 1) > for val1 in inputs: > for val2 in inputs: > if val1 is not val2: > find_solution(inputs + [val1 and val2], not_count) > find_solution(inputs + [val1 or val2], not_count) > > find_solution([i1, i2, i3], 0) I understand your approach, it has given me some ideas too. Thanks for this! > So, here's a crazy idea: Make i1, i2, i3 into objects of a type with > an __eq__ that actually does the verification. Schrodinger's Objects: > they might be True, might be False, and until you call __eq__, they're > in both states. This probably isn't the best way, but I think it's the > most fun! Haha, it surely is a very cool idea! Thanks for the ideas and your very cool approach. I'll try to tackle it myself (I think I have a good point to start) and will post the code once I'm finished. Best regards, Joe -- >> Wo hattest Du das Beben nochmal GENAU vorhergesagt? > Zumindest nicht öffentlich! Ah, der neueste und bis heute genialste Streich unsere großen Kosmologen: Die Geheim-Vorhersage. - Karl Kaos über Rüdiger Thomas in dsa <hidbv3$om2$1...@speranza.aioe.org> -- https://mail.python.org/mailman/listinfo/python-list
