Add day 9 solutions

4 files changed, 69 insertions, 0 deletions

diff --git a/2015/09/.gitignore b/2015/09/.gitignore
new file mode 100644
index 0000000..ffc46fe
--- /dev/null
+++ b/2015/09/.gitignore
@@ -0,0 +1 @@
+puzzle-[12].py
diff --git a/2015/09/Makefile b/2015/09/Makefile
new file mode 100644
index 0000000..247194a
--- /dev/null
+++ b/2015/09/Makefile
@@ -0,0 +1,8 @@
+all:
+	sed '/START PART 2/,/END PART 2/d' puzzles.py >puzzle-1.py
+	sed '/START PART 1/,/END PART 1/d' puzzles.py >puzzle-2.py
+	chmod +x puzzle-[12].py
+
+.PHONY: clean
+clean:
+	rm -f puzzle-[12].py
diff --git a/2015/09/input b/2015/09/input
new file mode 100644
index 0000000..97a6b63
--- /dev/null
+++ b/2015/09/input
@@ -0,0 +1,28 @@
+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
diff --git a/2015/09/puzzles.py b/2015/09/puzzles.py
new file mode 100644
index 0000000..e0d33b7
--- /dev/null
+++ b/2015/09/puzzles.py
@@ -0,0 +1,32 @@
+#!/usr/bin/env python3
+
+import itertools
+import re
+
+
+def main() -> None:
+	towns: set[str] = set()
+	distances: list[tuple[str, str, int]] = []
+	with open("input", "r", encoding="utf-8") as f:
+		for line in f.readlines():
+			f, t, d = re.match(r"(\w+) to (\w+) = (\d+)", line).groups()
+			towns.update({f, t})
+			distances.append((f, t, int(d)))
+
+	print(
+		# START PART 1
+		min(
+		# END PART 1 START PART 2
+		max(
+		# END PART 2
+			sum(
+				[d[2] for d in distances if part[0] in d and part[1] in d][0]
+				for part in zip(perm, perm[1:])
+			)
+			for perm in itertools.permutations(towns)
+		)
+	)
+
+
+if __name__ == "__main__":
+	main()