Op 09-12-13 12:49, Johannes Bauer schreef: > Hi group, > > it's somewhat OT here, but I have a puzzle to which I would like a > solution -- but I'm unsure how I should tackle the problem with Python. > But it's a fun puzzle, so maybe it'll be appreciated here. > > The question is: How do you design a boolean circuit that contains at > most 2 NOT gates, but may contain as many AND or OR gates that inverts > three inputs? IOW: Build three inverters by using only two inverters > (and an infinite amount of AND/OR). > > Surprisingly, this is possible (and I even know the solution, but won't > give it away just yet). > > I found this puzzle again and was thinking about: How would I code a > brute-force approach to this problem in Python? And to my surprise, it > isn't as easy as I thought. So I'm looking for some advice from you guys > (never huts to improve ones coding skills).
Well I would make some kind of connecter type, that would have a binary vector associated with it. How do we calculate bit n of a connector? Take the three input signals, i0, i1, i2, these can be seen as a binary digits. So suppose we have input 0, 1, 0 then bit 2 of the connector would be the value of that connector with these input signals. The original three connectors would have the following values: 01010101, 00110011, 00001111. What you can do now is make new connectors by combining them with an or, and or not port and search for those whose value is 10101010, 11001100 and 11110000. -- Antoon Pardon -- https://mail.python.org/mailman/listinfo/python-list
