Day 6: Guard Gallivant
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
- What is this?: Here is a post with a large amount of details: https://programming.dev/post/6637268
- Where do I participate?: https://adventofcode.com/
- Is there a leaderboard for the community?: We have a programming.dev leaderboard with the info on how to join in this post: https://programming.dev/post/6631465
C
Got super stumped on part 2. I’d add an obstacle for every tile on the path of part 1 but I kept getting wrong results, even after fixing some edge cases. Spent too much time looking at terminal dumps and mp4 visualisations.
Eventually I gave up and wrote a for(y) for(x) loop, trying an obstacle in every possible tile, and that gave the correct answer. Even that brute force took only 2.5 ish seconds on my 2015 PC! But having that solution allowed me to narrow it down again to a reasonably efficient version similar to what I had before. Still I don’t know where I went wrong the first time.
Code