2015 day 9.

src/holt59/aoc/2015/day9.py

@@ -0,0 +1,26 @@
+import itertools
+import sys
+from collections import defaultdict
+from typing import cast
+
+import parse  # type: ignore
+
+lines = sys.stdin.read().splitlines()
+
+distances: dict[str, dict[str, int]] = defaultdict(dict)
+for line in lines:
+    origin, destination, length = cast(
+        tuple[str, str, int], parse.parse("{} to {} = {:d}", line)  # type: ignore
+    )
+    distances[origin][destination] = distances[destination][origin] = length
+
+distance_of_routes = {
+    route: sum(distances[o][d] for o, d in zip(route[:-1], route[1:]))
+    for route in map(tuple, itertools.permutations(distances))
+}
+
+answer_1 = min(distance_of_routes.values())
+print(f"answer 1 is {answer_1}")
+
+answer_2 = max(distance_of_routes.values())
+print(f"answer 2 is {answer_2}")