day7_part2.py

#!/usr/bin/env python3

from collections import Counter
from enum import IntEnum
from typing import Mapping, Tuple

CARDS: Tuple[str, ...] = ('J', '2', '3', '4', '5', '6', '7', '8', '9', 'T', 'Q', 'K', 'A', )
CARDS_VALUES: Mapping[str, int] = {c: i for i, c in enumerate(CARDS, start=2)}


class HandRank(IntEnum):
    HIGH_CARD = 1
    PAIR = 2
    TWO_PAIRS = 3
    THREE_OF_A_KIND = 4
    FULL_HOUSE = 5
    FOUR_OF_A_KIND = 6
    FIVE_OF_A_KIND = 7


class Hand:
    __slots__ = ('cards', 'bid', 'rank', 'card_values', )

    def __init__(self, cards: str, bid: int):
        c = Counter(cards)

        self.cards = cards
        self.bid = bid

        self.card_values = [CARDS_VALUES[c] for c in cards]

        try:
            value = c.pop('J')
            if not c:
                c['A'] = value
            else:
                c[c.most_common(1)[0][0]] += value
        except KeyError:
            pass
    
        match len(c):
            case 1:
                self.rank = HandRank.FIVE_OF_A_KIND
            case 2:
                self.rank = HandRank.FOUR_OF_A_KIND if 4 in c.values() else HandRank.FULL_HOUSE
            case 3:
                self.rank = HandRank.THREE_OF_A_KIND if 3 in c.values() else HandRank.TWO_PAIRS
            case 4:
                self.rank = HandRank.PAIR
            case _:   
                self.rank = HandRank.HIGH_CARD
    
    def __lt__(self, other: 'Hand') -> bool:
        return (self.rank, self.card_values) < (other.rank, other.card_values)
    
    def __repr__(self) -> str:
        return f"{self.cards} {self.bid}"
    

with open("input.txt") as f:
    hands = []
    for line in f:
        cards, bid = line.strip().split(maxsplit=1)
        hands.append(Hand(cards, int(bid)))

    hands.sort()

    print(sum(i * h.bid for i, h in enumerate(hands, start=1)))