In this series, I'll share my progress with the 2023 version of Advent of Code.

Check the first post for a short intro to this series.

You can also follow my progress on GitHub.

## December 7th

The puzzle of day 7 was fun. A bit of sorting and a bit of recursion, not too hard. It did take me more code than I was expecting.

**My pitfall for this puzzle:** The code is not very readable and inelegant at some places, that caused some bugs 🐛

## Solution here, do not click if you want to solve the puzzle first yourself

```
#!/usr/bin/env python3
from collections import Counter
from functools import cmp_to_key
with open('input.txt') as infile:
lines = infile.readlines()
hands = []
for line in lines:
parts = line.strip().split(' ')
hands.append((parts[0], int(parts[1])))
def replace_jokers(cards):
jokers = [c for c in cards if c == 'J']
if len(jokers) == 0:
return [cards]
elif len(jokers) == 5:
return ['AAAAA']
else:
order = ['A', 'K', 'Q', 'T', '9', '8', '7', '6', '5', '4', '3', '2']
result = []
for c in order:
result.extend(replace_jokers(cards.replace('J', c, 1)))
return result
def use_jokers(cards):
combinations = replace_jokers(cards)
return sort_cards_list([(c, c) for c in combinations])[-1]
def rank_cards(cards):
counter = Counter(cards)
counts = [i[1] for i in counter.most_common()]
if counts[0] == 5:
return 7
elif counts[0] == 4:
return 6
elif counts[0] == 3 and counts[1] == 2:
return 5
elif counts[0] == 3:
return 4
elif counts[0] == 2 and counts[1] == 2:
return 3
elif counts[0] == 2:
return 2
else:
return 1
def compare_cards(cards1, cards2):
order = ['A', 'K', 'Q', 'T', '9', '8', '7', '6', '5', '4', '3', '2', \
'J']
result = rank_cards(cards1[1]) - rank_cards(cards2[1])
if result == 0:
for idx, card in enumerate(cards1[0]):
if order.index(card) < order.index(cards2[0][idx]):
return 1
if order.index(card) > order.index(cards2[0][idx]):
return -1
return result
def sort_cards_list(cards_list):
return sorted(cards_list, key=cmp_to_key(compare_cards))
def sort_hands(hands):
def compare(hand1, hand2):
return compare_cards((hand1[0], hand1[2]), (hand2[0], hand2[2]))
return sorted(hands, key=cmp_to_key(compare))
hands_with_strongest = []
for hand in hands:
strongest = use_jokers(hand[0])[0]
hand_with_strongest = (hand[0], hand[1], strongest)
hands_with_strongest.append(hand_with_strongest)
hands_with_strongest = sort_hands(hands_with_strongest)
sum = 0
for index, hand in enumerate(hands_with_strongest):
sum += (index + 1) * hand[1]
print(sum)
```

That's it! See you again tomorrow!

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