7.md

Day 7

A very fun puzzle!

	Part 1	Part 2	Total
Time	15:44	17:25	33:09

Part 1

It was super fun to come up with a hand classifier for poker cards. I'm proud of the way I did it too, and using custom sorting functions for ordering the matching cards. I suppose I could have done the whole thing in a single sorting function too, that might've been cool.

from helpers.datagetter import aocd_data_in
from collections import defaultdict

din, aocd_submit = aocd_data_in(split=True, numbers=False)
ans = 0

cards = ["2", "3", "4", "5", "6", "7", "8", "9", "T", "J", "Q", "K", "A"]


def classify(hand):
    hand_set = list(set(hand))
    if len(hand_set) == 1:
        return 6
    elif len(hand_set) == 2:
        if hand.count(hand[0]) in [2, 3]:
            return 4
        else: 
            return 5
    elif len(hand_set) == 3:
        if 3 in [hand.count(hand_set[0]), hand.count(hand_set[1]), hand.count(hand_set[2])]:
            return 3
        else:
            return 2
    elif len(hand_set) == 4:
        return 1
    return 0


games = defaultdict(list)
games_score = {}

for game in din:
    hand = game.split(" ")[0]
    bid = game.split(" ")[1]

    games[classify([*hand])].append(hand)
    games_score[hand] = bid

rank = 0
for i in range(7):
    games[i].sort(key=lambda x: [cards.index(c) for c in x])
    for item in games[i]:
        rank += 1
        ans += rank * int(games_score[item])


aocd_submit(ans)

Part 2

My immediate plan was to try all the permutations of joker replacements, since it wouldn't be that many per hand. But... I should have tried all products first and that ended up biting me because I did all the work to replace the jokers and then kept failing since the permutations would naturally not try putting in the same two or more characters for replacement jokers.

from helpers.datagetter import aocd_data_in
from collections import defaultdict
from itertools import product

din, aocd_submit = aocd_data_in(split=True, numbers=False)
ans = 0

cards = ["J", "2", "3", "4", "5", "6", "7", "8", "9", "T", "Q", "K", "A"]


def classify_old(hand):
    hand_set = list(set(hand))
    if len(hand_set) == 1:
        return 6
    elif len(hand_set) == 2:
        if hand.count(hand[0]) in [2, 3]:
            return 4
        else:
            return 5
    elif len(hand_set) == 3:
        if 3 in [hand.count(hand_set[0]), hand.count(hand_set[1]), hand.count(hand_set[2])]:
            return 3
        else:
            return 2
    elif len(hand_set) == 4:
        return 1
    return 0

def classify(hand):
    num_jokers = hand.count("J")
    jokers_locations = [i for i in range(len(hand)) if hand[i] == "J"]
    best = 0
    if num_jokers == 0:
        return classify_old(hand)
    for new_hand in product(cards[1:], repeat=num_jokers):
        j_hand = ""
        j = 0
        for i in range(len(hand)):
            if i in jokers_locations:
                j_hand += new_hand[j]
                j += 1
            else:
                j_hand += hand[i]
        best = max(classify_old(j_hand), best)
    return best


games = defaultdict(list)
games_score = {}

for game in din:
    hand = game.split(" ")[0]
    bid = game.split(" ")[1]

    games[classify([*hand])].append(hand)
    games_score[hand] = bid

rank = 0
for i in range(7):
    games[i].sort(key=lambda x: [cards.index(c) for c in x])
    for item in games[i]:
        rank += 1
        ans += rank * int(games_score[item])


aocd_submit(ans)