aoc2021/day21.py
2021-12-21 08:54:59 +01:00

57 lines
1.9 KiB
Python

from tools.aoc import AOCDay
from typing import Any
class Day(AOCDay):
test_solutions_p1 = [739785]
test_solutions_p2 = [444356092776315]
def part1(self) -> Any:
pos = list(map(int, [x.split(": ")[1] for x in self.getInput()]))
scores = [0, 0]
target_score = 1000
rolls = 0
dice_roll = 0
while scores[0] < target_score and scores[1] < target_score:
for player in [0, 1]:
this_roll = 0
rolls += 3
for _ in range(3):
dice_roll = 1 + (dice_roll % 100)
this_roll += dice_roll
pos[player] = 1 + (this_roll + pos[player] - 1) % 10
scores[player] += pos[player]
if scores[player] >= target_score:
break
return min(scores) * rolls
def roll_dirac(self, pos1, pos2, score1, score2, cache):
if (pos1, pos2, score1, score2) in cache:
return cache[(pos1, pos2, score1, score2)]
p1wins = 0
p2wins = 0
target_score = 21
for roll1 in range(3, 10):
tpos1 = 1 + (roll1 + pos1 - 1) % 10
if score1 + tpos1 >= target_score:
p1wins += 27
else:
for roll2 in range(3, 10):
tpos2 = 1 + (roll2 + pos2 - 1) % 10
if score2 + tpos2 >= target_score:
p2wins += 27
else:
sub_p1wins, sub_p2wins = self.roll_dirac(tpos1, tpos2, score1 + tpos1, score2 + tpos2, cache)
p1wins += sub_p1wins
p2wins += sub_p2wins
cache[(pos1, pos2, score1, score2)] = p1wins, p2wins
return p1wins, p2wins
def part2(self) -> Any:
pos = list(map(int, [x.split(": ")[1] for x in self.getInput()]))
wins1, wins2 = self.roll_dirac(pos[0], pos[1], 0, 0, {})
return wins1, wins2