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advent-of-code-2k23/day7/day7.py
2023-12-13 13:37:00 +01:00

71 lines
2.1 KiB
Python

from collections import Counter
def calculate_rank(hand, part2=False):
card_ranks = {'2': 1, '3': 2, '4': 3, '5': 4, '6': 5, '7': 6, '8': 7, '9': 8, 'T': 9, 'J': 10, 'Q': 11, 'K': 12, 'A': 13}
if part2:
# in part2, jokers are the weakest card
card_ranks['J'] = 0
# substitute cards with their ranks to make them sortable
hand = [card_ranks[c] for c in hand]
cnt = Counter(hand)
if part2 and cnt[0] != 5: # edge case if hand == 'JJJJJ'
# substitute jokers with the most common card that isn't a joker
most_common_card = cnt.most_common(2)[0][0] if cnt.most_common(2)[0][0] != 0 else cnt.most_common(2)[1][0]
new_hand = [most_common_card if c == 0 else c for c in hand]
cnt = Counter(new_hand)
rank = 0
match sorted(cnt.values()):
case [5]: rank = 7
case [1, 4]: rank = 6
case [2, 3]: rank = 5
case [1, 1, 3]: rank = 4
case [1, 2, 2]: rank = 3
case [1, 1, 1, 2]: rank = 2
case [1, 1, 1, 1, 1]: rank = 1
# return rank, and hand as a tiebreaker
return (rank, hand)
def parse_input(inp):
hands = [l.strip().split() for l in inp.strip().split("\n")]
return hands
def calculate_wins(hands, part2=False):
total = 0
hands = sorted(hands, key=lambda hb: calculate_rank(hb[0], part2=part2))
for rank, hand in enumerate(hands):
hand, bid = hand
total += (rank + 1) * int(bid)
return total
if __name__ == "__main__":
sample_input = """
32T3K 765
T55J5 684
KK677 28
KTJJT 220
QQQJA 483
"""
res = calculate_wins(parse_input(sample_input))
print(f"part 1 example: {res}")
assert res == 6440
res = calculate_wins(parse_input(sample_input), part2=True)
print(f"part 2 example: {res}")
assert res == 5905
import sys
if len(sys.argv) == 2:
with open(sys.argv[1]) as f:
inp = parse_input(f.read())
res = calculate_wins(inp)
print(f"Part 1, res={res}")
res = calculate_wins(inp, part2=True)
print(f"Part 2, res={res}")