aoc/2023/07/07.py

from collections import defaultdict, Counter

with open("input.txt") as f:
	hands = f.read().split("\n")
	hands = [(hand.split()[0], int(hand.split()[1])) for hand in hands]
	

def rank(hands):
	ranked = defaultdict(list)
	for hand in hands:
		r = get_rank(hand)
		ranked[r].append(hand)
	return ranked

def get_rank(hand):
	c = Counter(hand[0])
	counts = c.most_common(2)
	# extract counts
	first = counts[0][1]
	second = counts[1][1] if len(counts) == 2 else 0
	# discriminate based on counts
	d = (first, second)
	match d:
		case (1,1):
			return "HC" # high card
		case (2,1):
			return "1P" # one pair
		case (2,2):
			return "2P" # two pair
		case (3,1):
			return "3K" # three of a kind
		case (3,2):
			return "FH" # full house
		case (4,1):
			return "4K" # four of a kind
		case (5,0):
			return "5K" # five of a kind

def order(hand: str):
	"""
	Convert to base-15 for proper sorting
	"""
	# A = ten
	# B = jack
	# C = queen
	# D = king
	# E = ace
	return hand.replace(
		"A", "E"
	).replace(
		"K", "D"
	).replace(
		"Q", "C"
	).replace(
		"J", "B"
	).replace(
		"T", "A"
	)

def part1(hands):
	ranked = rank(hands)
	ranked_hands = []
	ranked_hands += sorted(ranked["HC"], key=lambda hand: order(hand[0]))
	ranked_hands += sorted(ranked["1P"], key=lambda hand: order(hand[0]))
	ranked_hands += sorted(ranked["2P"], key=lambda hand: order(hand[0]))
	ranked_hands += sorted(ranked["3K"], key=lambda hand: order(hand[0]))
	ranked_hands += sorted(ranked["FH"], key=lambda hand: order(hand[0]))
	ranked_hands += sorted(ranked["4K"], key=lambda hand: order(hand[0]))
	ranked_hands += sorted(ranked["5K"], key=lambda hand: order(hand[0]))
	answer = sum(
		[
			hand[1] * (rank + 1)
			for rank, hand in enumerate(ranked_hands)
		]
	)
	print(answer)

part1(hands)

### Part 2

def order2(hand: str):
	"""
	Convert to base-15 for proper sorting
	"""
	# A = ten
	# B = jack
	# C = queen
	# D = king
	# E = ace
	return hand.replace(
		"A", "E"
	).replace(
		"K", "D"
	).replace(
		"Q", "C"
	).replace(
		"J", "1"  # jokers are worth less than 2
	).replace(
		"T", "A"
	)

def get_rank2(hand):
	c1 = Counter(hand[0])
	c2 = Counter(hand[0].replace("J", ""))
	jokers_count = c1.get("J") or 0
	counts = c2.most_common(2)
	if not counts:
		counts = [('', 0),('', 0)]  # prevent index error when 5 jokers
	# extract counts
	first = counts[0][1] + jokers_count  # convert jokers to highest-scoring card
	second = counts[1][1] if len(counts) == 2 else 0
	# discriminate based on counts
	d = (first, second)
	match d:
		case (1,1):
			return "HC" # high card
		case (2,1):
			return "1P" # one pair
		case (2,2):
			return "2P" # two pair
		case (3,1):
			return "3K" # three of a kind
		case (3,2):
			return "FH" # full house
		case (4,1):
			return "4K" # four of a kind
		case (5,0):
			return "5K" # five of a kind
		
def rank2(hands):
	ranked = defaultdict(list)
	for hand in hands:
		r = get_rank2(hand)
		ranked[r].append(hand)
	return ranked

def part2(hands):
	ranked = rank2(hands)
	ranked_hands = []
	ranked_hands += sorted(ranked["HC"], key=lambda hand: order2(hand[0]))
	ranked_hands += sorted(ranked["1P"], key=lambda hand: order2(hand[0]))
	ranked_hands += sorted(ranked["2P"], key=lambda hand: order2(hand[0]))
	ranked_hands += sorted(ranked["3K"], key=lambda hand: order2(hand[0]))
	ranked_hands += sorted(ranked["FH"], key=lambda hand: order2(hand[0]))
	ranked_hands += sorted(ranked["4K"], key=lambda hand: order2(hand[0]))
	ranked_hands += sorted(ranked["5K"], key=lambda hand: order2(hand[0]))
	answer = sum(
		[
			hand[1] * (rank + 1)
			for rank, hand in enumerate(ranked_hands)
		]
	)
	print(answer)

part2(hands)