Day 14: Parabolic Reflector Dish

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  • janAkaliEnglish
    3•7 months ago

    Nim

    Part 1: I made the only procedure - to roll rocks to the right. First, I rotate input 90 degrees clockwise. Then roll rocks in each row. To roll a row of rocks - I scan from right to left, until I find a rock and try to find the most right available position for it. Not the best approach, but not the worst either.
    Part 2: To do a cycle I use the same principle as part 1: (rotate clockwise + roll rocks right) x 4 = 1 cycle. A trillion cycles would obviously take too long. Instead, I cycle the input and add every configuration to a hashTable and once we reach a full copy of one of previous cycles - it means we’re in a loop. And then finding out in what configuration rocks will be after trillion steps is easy with use of a modulo.

    Total Runtime: 60ms relatively slow today =(
    Puzzle rating: 7/10
    Code: day_14/solution.nim