Day 17: Chronospatial Computer

Megathread guidelines

  • Keep top level comments as only solutions, if you want to say something other than a solution put it in a new post. (replies to comments can be whatever)
  • You can send code in code blocks by using three backticks, the code, and then three backticks or use something such as https://topaz.github.io/paste/ if you prefer sending it through a URL

FAQ

  • SteveDinn@lemmy.ca
    3·
    23 hours ago

    I’m confused reading the buildQuine() method. It reads to me that when you call it from the top level with top = true, A0 will be set to 0, and then when we get to the 0 to 8 loop, the ‘A’ register will be 0 * 8 + 0 for the first iteration, and then recurse with top = false, but with a0 still ending up 0, causing infinite recursion.

    Am I missing something?

    I got it to work with a check that avoids the recursion if the last state’s A register value is the same as the new state’s value.

    • mykl@lemmy.world
      3·
      22 hours ago

      Oh, good catch. That’s certainly the case if an initial value of 0 correctly generates the required value of the quine. As I’d already started running some code against the live data that’s what I tested against, and so it’s only when I just tested it against the example data that I saw the problem.

      I have changed the for-loop to read for (var a in (top ? 1 : 0).to(8)) for maximum terseness :-)

      That still works for the example and my live data, and I don’t think there should be a valid solution that relies on the first triplet being 0. Thanks for your reply!