2025: d06: ex2: add solution

2025/d06/ex2/ex2.py

@@ -0,0 +1,44 @@
+#!/usr/bin/env python
+
+import enum
+import functools
+import operator
+import sys
+
+
+class Op(enum.StrEnum):
+    ADD = "+"
+    MUL = "*"
+
+
+def solve(input: list[str]) -> int:
+    def from_cephalopod(input: list[str]) -> list[str]:
+        transposed = list(map("".join, zip(*input, strict=True)))
+        # If a value is only spaces, it should become newlines in the transpose
+        transposed = [n if not n.isspace() else "\n" for n in transposed]
+        return " ".join(transposed).splitlines()
+
+    def parse(input: list[str]) -> tuple[list[list[int]], list[Op]]:
+        raw_nums, raw_ops = input[:-1], input[-1]
+        matrix = [[int(n) for n in line.split()] for line in from_cephalopod(raw_nums)]
+        ops = [Op(c) for c in raw_ops.split()]
+        return matrix, ops
+
+    def apply(op: Op, nums: list[int]) -> int:
+        f = {
+            Op.ADD: operator.add,
+            Op.MUL: operator.mul,
+        }[op]
+        return functools.reduce(f, nums)
+
+    matrix, ops = parse(input)
+    return sum(apply(op, nums) for op, nums in zip(ops, matrix, strict=True))
+
+
+def main() -> None:
+    input = sys.stdin.read().splitlines()
+    print(solve(input))
+
+
+if __name__ == "__main__":
+    main()