advent/2018/09.py

from collections import deque, Counter
import re


def simulate(num_players, last_marble):
    circle = deque([0])
    players = Counter()
    current_turn = 1
    while current_turn <= last_marble:
        current_player = (current_turn % num_players) - 1
        
        if current_turn % 23 == 0:
            players[current_player] += current_turn
            circle.rotate(7)
            players[current_player] += circle.popleft()
        else:
            circle.rotate(-2)
            circle.appendleft(current_turn)
        current_turn += 1
    return players.most_common()[0][1]


with open('data/09.txt') as f:
    m = re.match(r'(\d+) players; last marble is worth (\d+) points', f.read())
    num_players = int(m.groups()[0])
    last_marble = int(m.groups()[1])

print(f'Part 1: {simulate(num_players, last_marble)}\n')
print(f'Part 2: {simulate(num_players, last_marble * 100)}\n')