Day 11: Cosmic Expansion

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)
  • Code block support is not fully rolled out yet but likely will be in the middle of the event. Try to share solutions as both code blocks and using something such as https://topaz.github.io/paste/ , pastebin, or github (code blocks to future proof it for when 0.19 comes out and since code blocks currently function in some apps and some instances as well if they are running a 0.19 beta)

FAQ

🔒 Thread is locked until there’s at least 100 2 star entries on the global leaderboard

🔓 Unlocked after 9 mins

  • @to_urcite_ty_kokosEnglish
    2•6 months ago

    Kotlin

    Github

    Was lazy at the beginning, so I started to do actual expansion in memory, then decided to do it properly. And it paid off in the second part.

    • find galaxy coordinates + hold few bit masks to find unused rows and columns → convert to indexes
    • transform original galaxies coordinates considering number of previous empty lines (time for simple binary search)
    • use the Manhattan distance