50 lines
1.7 KiB
Python
50 lines
1.7 KiB
Python
# SPDX-License-Identifier: MIT
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# Copyright (c) 2021 Akumatic
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#
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# https://adventofcode.com/2021/day/21
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def read_file(filename: str = "input.txt") -> tuple:
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with open(f"{__file__.rstrip('code.py')}{filename}", "r") as f:
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return [int(line[28:]) for line in f.read().strip().split("\n")]
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def game_deterministic(positions: list) -> tuple:
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pos = positions[:]
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player, rolls, die = 0, 0, 0
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scores = [0, 0]
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while max(scores) < 1000:
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for _ in range(3):
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die = (die + 1) % 100 or 100
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rolls += 1
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pos[player] = (pos[player] + die) % 10 or 10
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scores[player] += pos[player]
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player = (player + 1) % 2
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return rolls, scores
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def game_dirac(move_frequency: dict, wins: list, positions: list,
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scores: list = [0, 0], player: int = 0, win_mult: int = 1) -> None:
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next_player = (player + 1) % 2
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for moves in move_frequency:
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pos, scr = positions[:], scores[:]
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pos[player] = (pos[player] + moves) % 10 or 10
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scr[player] += pos[player]
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next_mult = move_frequency[moves] * win_mult
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if scr[player] < 21:
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game_dirac(move_frequency, wins, pos, scr, next_player, next_mult)
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else:
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wins[player] += next_mult
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def part1(start_positions: list) -> int:
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rolls, scores = game_deterministic(start_positions)
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return rolls * min(scores)
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def part2(start_positions: list) -> int:
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move_frequency = {3: 1, 4: 3, 5: 6, 6: 7, 7: 6, 8: 3, 9: 1}
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wins = [0, 0]
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game_dirac(move_frequency, wins, start_positions)
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return max(wins)
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if __name__ == "__main__":
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vals = read_file()
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print(f"Part 1: {part1(vals)}")
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print(f"Part 2: {part2(vals)}")
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