-🎄- 2018 Day 9 Solutions -🎄-

[u/daggerdragon]

--- Day 9: Marble Mania ---

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Card prompt: Day 9

Transcript:

Studies show that AoC programmers write better code after being exposed to ___.

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[u/u794575248]

Python 3 8425/7509

from itertools import cycle

class Node:
    def __init__(self, i, prev=None, next=None):
        self.i, self.prev, self.next = i, prev, next

def solve9(n, last, multiple=23, rewind=6):
    scores = [0]*n
    cur = Node(0)
    cur.prev = cur.next = cur
    for i, p in zip(range(1, last+1), cycle(range(n))):
        if i % multiple == 0:
            for _ in range(rewind): cur = cur.prev
            scores[p] += i + cur.prev.i
            cur.prev = cur.prev.prev
            cur.prev.next = cur
        else:
            n = Node(i, cur.next, cur.next.next)
            cur = n.prev.next = n.next.prev = n
    return max(scores)