advent-of-code/2023/day7.py

import sys
from collections import Counter, defaultdict


class HandTypes:
    HIGH_CARD = 0
    ONE_PAIR = 1
    TWO_PAIR = 2
    THREE_OF_A_KIND = 3
    FULL_HOUSE = 4
    FOUR_OF_A_KIND = 5
    FIVE_OF_A_KIND = 6


# mapping from number of different cards + highest count of card to the hand type
LEN_LAST_TO_TYPE: dict[int, dict[int, int]] = {
    1: defaultdict(lambda: HandTypes.FIVE_OF_A_KIND),
    2: defaultdict(lambda: HandTypes.FULL_HOUSE, {4: HandTypes.FOUR_OF_A_KIND}),
    3: defaultdict(lambda: HandTypes.TWO_PAIR, {3: HandTypes.THREE_OF_A_KIND}),
    4: defaultdict(lambda: HandTypes.ONE_PAIR),
    5: defaultdict(lambda: HandTypes.HIGH_CARD),
}


def extract_key(hand: str, values: dict[str, int], joker: str = "0") -> tuple[int, ...]:
    # get count of each cards, in increasing count - the 'or' part handles the JJJJJ
    # case when joker is True
    cnt = sorted(Counter(hand.replace(joker, "")).values()) or [0]

    return (LEN_LAST_TO_TYPE[len(cnt)][cnt[-1] + hand.count(joker)],) + tuple(
        values[c] for c in hand
    )


lines = sys.stdin.read().splitlines()
cards = [(t[0], int(t[1])) for line in lines if (t := line.split())]


# part 1
values = {card: value for value, card in enumerate("23456789TJQKA")}
cards.sort(key=lambda cv: extract_key(cv[0], values=values))
answer_1 = sum(rank * value for rank, (_, value) in enumerate(cards, start=1))
print(f"answer 1 is {answer_1}")

# part 2
values = {card: value for value, card in enumerate("J23456789TQKA")}
cards.sort(key=lambda cv: extract_key(cv[0], values=values, joker="J"))
answer_2 = sum(rank * value for rank, (_, value) in enumerate(cards, start=1))
print(f"answer 2 is {answer_2}")