Add 2025 day 11 solutions

1 files changed, 37 insertions, 0 deletions

diff --git a/2025/11/puzzle-2.py b/2025/11/puzzle-2.py
new file mode 100755
index 0000000..629c10c
--- /dev/null
+++ b/2025/11/puzzle-2.py
@@ -0,0 +1,37 @@
+#!/usr/bin/python3
+
+import functools
+
+
+paths: dict[str, list[str]] = {}
+
+def main() -> None:
+	with open('input', 'r') as f:
+		for line in f.readlines():
+			x, *xs = line.split()
+			paths[x[:-1]] = xs
+
+	print(npaths('svr', 'out'))
+
+
+@functools.cache
+def npaths(
+	src: str,
+	dst: str,
+	dacp: bool = False,
+	fftp: bool = False,
+) -> bool | int:
+	return (
+		dacp and fftp
+		if src == dst else
+		sum(npaths(
+			nsrc,
+			dst,
+			dacp or src == 'dac',
+			fftp or src == 'fft',
+		) for nsrc in paths[src])
+	)
+
+
+if __name__ == '__main__':
+	main()