69 lines
1.8 KiB
Python
69 lines
1.8 KiB
Python
from tools.aoc import AOCDay
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from tools.tools import cache
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from typing import Any
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# 1 way to roll a 3, 3 ways to roll a 4, ...
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ROLLS = [(1, 3), (3, 4), (6, 5), (7, 6), (6, 7), (3, 8), (1, 9)]
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@cache
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def roll(pos1: int, pos2: int, score1: int = 0, score2: int = 0) -> (int, int):
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if score2 >= 21:
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return 0, 1
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p1wins = p2wins = 0
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for sub_universes, pos_inc in ROLLS:
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new_pos1 = 1 + (pos_inc + pos1 - 1) % 10
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# notice the switch-a-roo!
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sub_p2wins, sub_p1wins = roll(pos2, new_pos1, score2, score1 + new_pos1)
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p1wins += sub_p1wins * sub_universes
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p2wins += sub_p2wins * sub_universes
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return p1wins, p2wins
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class Day(AOCDay):
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inputs = [
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[
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(739785, "test_input21"),
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(551901, "input21")
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],
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[
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(444356092776315, "test_input21"),
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(272847859601291, "input21")
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]
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]
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def part1(self) -> Any:
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pos = list(map(int, [x.split(": ")[1] for x in self.getInput()]))
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scores = [0, 0]
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target_score = 1000
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rolls = 0
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dice_roll = 0
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while scores[0] < target_score and scores[1] < target_score:
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for player in range(2):
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this_roll = 0
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rolls += 3
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for _ in range(3):
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dice_roll = 1 + (dice_roll % 100)
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this_roll += dice_roll
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pos[player] = 1 + (this_roll + pos[player] - 1) % 10
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scores[player] += pos[player]
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if scores[player] >= target_score:
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break
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return min(scores) * rolls
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def part2(self) -> Any:
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pos1, pos2 = map(int, [x.split(": ")[1] for x in self.getInput()])
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wins1, wins2 = roll(pos1, pos2)
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return max(wins1, wins2)
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if __name__ == '__main__':
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day = Day(21)
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day.run(verbose=True)
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