2015 day 9.

src/holt59/aoc/2015/day9.py

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+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}")

src/holt59/aoc/inputs/holt59/2015/day9.txt

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+Faerun to Tristram = 65
+Faerun to Tambi = 129
+Faerun to Norrath = 144
+Faerun to Snowdin = 71
+Faerun to Straylight = 137
+Faerun to AlphaCentauri = 3
+Faerun to Arbre = 149
+Tristram to Tambi = 63
+Tristram to Norrath = 4
+Tristram to Snowdin = 105
+Tristram to Straylight = 125
+Tristram to AlphaCentauri = 55
+Tristram to Arbre = 14
+Tambi to Norrath = 68
+Tambi to Snowdin = 52
+Tambi to Straylight = 65
+Tambi to AlphaCentauri = 22
+Tambi to Arbre = 143
+Norrath to Snowdin = 8
+Norrath to Straylight = 23
+Norrath to AlphaCentauri = 136
+Norrath to Arbre = 115
+Snowdin to Straylight = 101
+Snowdin to AlphaCentauri = 84
+Snowdin to Arbre = 96
+Straylight to AlphaCentauri = 107
+Straylight to Arbre = 14
+AlphaCentauri to Arbre = 46

src/holt59/aoc/inputs/tests/2015/day9.txt

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+London to Dublin = 464
+London to Belfast = 518
+Dublin to Belfast = 141