2023: d07: ex1: add solution

2023/d07/ex1/ex1.py

@@ -0,0 +1,56 @@
+#!/usr/bin/env python
+
+import functools
+import sys
+from collections import Counter
+
+Play = tuple[str, int]
+
+ORDER = "23456789TJQKA"
+
+
+def solve(input: list[str]) -> int:
+    def parse(input: list[str]) -> list[Play]:
+        return [(hand, int(bid)) for hand, bid in map(str.split, input)]
+
+    # Stronger hands compare higher than weaker hands
+    def cmp_hand(lhs: str, rhs: str) -> int:
+        def to_type(hand: str) -> list[int]:
+            return [count for _, count in Counter(hand).most_common()]
+
+        def cmp_type(lhs: list[int], rhs: list[int]) -> int:
+            for left, right in zip(lhs, rhs):
+                if (cmp := left - right) != 0:
+                    return cmp
+            return 0
+
+        def cmp_card(lhs: str, rhs: str) -> int:
+            assert lhs in ORDER and rhs in ORDER  # Sanity check
+            assert len(lhs) == 1 and len(rhs) == 1  # Sanity check
+            return ORDER.find(lhs) - ORDER.find(rhs)
+
+        if (cmp := cmp_type(to_type(lhs), to_type(rhs))) != 0:
+            return cmp
+
+        for left, right in zip(lhs, rhs):
+            if (cmp := cmp_card(left, right)) != 0:
+                return cmp
+
+        return 0
+
+    def cmp_play(lhs: Play, rhs: Play) -> int:
+        return cmp_hand(lhs[0], rhs[0])
+
+    plays = parse(input)
+    plays = sorted(plays, key=functools.cmp_to_key(cmp_play))
+
+    return sum(rank * bid for rank, (_, bid) in enumerate(plays, start=1))
+
+
+def main() -> None:
+    input = sys.stdin.read().splitlines()
+    print(solve(input))
+
+
+if __name__ == "__main__":
+    main()