aoc2020/day22.py
Stefan Harmuth 7f8895c2c1 day22
2020-12-22 08:38:38 +01:00

56 lines
1.7 KiB
Python

import aoclib
DAY = 22
TEST_SOLUTION_PART1 = 306
TEST_SOLUTION_PART2 = 291
def play(player1_cards, player2_cards, recursive_combat=False):
previous_rounds = set()
while player1_cards and player2_cards:
if recursive_combat:
deck_tuple = (tuple(player1_cards), tuple(player2_cards))
if deck_tuple in previous_rounds:
return 1, player1_cards
else:
previous_rounds.add(deck_tuple)
card1 = player1_cards.pop(0)
card2 = player2_cards.pop(0)
if not recursive_combat:
if card1 > card2:
player1_cards.extend([card1, card2])
else:
player2_cards.extend([card2, card1])
else:
if len(player1_cards) >= card1 and len(player2_cards) >= card2:
winner, _ = play(player1_cards.copy()[:card1], player2_cards.copy()[:card2], True)
else:
winner = 1 if card1 > card2 else 2
if winner == 1:
player1_cards.extend([card1, card2])
else:
player2_cards.extend([card2, card1])
winner = (1, player1_cards) if len(player1_cards) else (2, player2_cards)
return winner
def part1(test_mode=False, recursive_combat=False):
my_input = aoclib.getMultiLineInputAsArray(day=DAY, test=test_mode)
player1 = [int(x) for x in my_input[0][1:]]
player2 = [int(x) for x in my_input[1][1:]]
_, winner = play(player1, player2, recursive_combat)
answer = 0
for x, c in enumerate(winner):
answer += (len(winner) - x) * c
return answer
def part2(test_mode=False):
return part1(test_mode, recursive_combat=True)