Day 7

aoc_cas/aoc2023/day7.py

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+import dataclasses
+from collections import Counter
+from functools import cache
+from typing import Iterator
+
+HIGH_CARD_A: dict[str, int] = {
+    c: i for i, c in enumerate(["A", "K", "Q", "J", "T", "9", "8", "7", "6", "5", "4", "3", "2"])
+}
+HIGH_CARD_B: dict[str, int] = {
+    c: i for i, c in enumerate(["A", "K", "Q", "T", "9", "8", "7", "6", "5", "4", "3", "2", "J"])
+}
+
+
+def hand_strength(matching_label_count: list[int, ...]) -> int:
+    match matching_label_count:
+        case [5]:
+            return 0
+        case [1, 4]:
+            return 1
+        case [2, 3]:
+            return 2
+        case [1, 1, 3]:
+            return 3
+        case [1, 2, 2]:
+            return 4
+        case [1, 1, 1, 2]:
+            return 5
+        case [1, 1, 1, 1, 1]:
+            return 6
+    raise ValueError(matching_label_count)
+
+
+@dataclasses.dataclass(frozen=True)
+class Hand:
+    cards: tuple[str]
+    bid: int
+
+    @cache
+    def part_a_cmp(self) -> tuple[int, tuple[int, ...]]:
+        matching_label_count = sorted(Counter(self.cards).values())
+        strength = hand_strength(matching_label_count)
+        high_card = tuple(HIGH_CARD_A[c] for c in self.cards)
+        return strength, high_card
+
+    @cache
+    def part_b_cmp(self) -> tuple[int, tuple[int, ...]]:
+        count = Counter(self.cards)
+        joker_count = count.pop("J", 0)
+        matching_label_count = sorted(count.values())
+        if joker_count == 5:
+            matching_label_count = [5]
+        else:
+            matching_label_count[-1] += joker_count
+        strength = hand_strength(matching_label_count)
+        high_card = tuple(HIGH_CARD_B[c] for c in self.cards)
+        return strength, high_card
+
+
+def parse(data: str) -> Iterator[Hand]:
+    for line in data.splitlines():
+        cards, bid = line.split(" ")
+        yield Hand(cards=tuple(cards), bid=int(bid))
+
+
+def part_a(data: str) -> int:
+    hands = sorted(parse(data), key=Hand.part_a_cmp, reverse=True)
+    result = 0
+    for rank, hand in enumerate(hands, start=1):
+        result += rank * hand.bid
+    return result
+
+
+def part_b(data: str) -> int:
+    hands = sorted(parse(data), key=Hand.part_b_cmp, reverse=True)
+    result = 0
+    for rank, hand in enumerate(hands, start=1):
+        result += rank * hand.bid
+    return result
+
+
+if __name__ == "__main__":
+    from aoc_cas.util import solve_with_examples
+
+    solve_with_examples(year=2023, day=7)

tests/fixtures/2023/7.txt

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+32T3K 765
+T55J5 684
+KK677 28
+KTJJT 220
+QQQJA 483
+6440
+5905