From a82498c4141728069d80418e26196193c451a1cd Mon Sep 17 00:00:00 2001
From: Thomas Voss <mail@thomasvoss.com>
Date: Sun, 22 Dec 2024 19:52:17 +0100
Subject: Add 2024 day 22 solutions

---
 2024/22/puzzles.py | 60 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)
 create mode 100644 2024/22/puzzles.py

(limited to '2024/22/puzzles.py')

diff --git a/2024/22/puzzles.py b/2024/22/puzzles.py
new file mode 100644
index 0000000..dff825f
--- /dev/null
+++ b/2024/22/puzzles.py
@@ -0,0 +1,60 @@
+#!/usr/bin/python3
+
+import collections
+from typing import Deque, Iterable
+
+
+type Diff = tuple[int, int, int, int]
+
+
+def main() -> None:
+	with open("input", "r") as f:
+		xs = map(int, f.readlines())
+
+	# START PART 1
+	print(sum(map(lastfrom, map(secrets, xs))))
+	# END PART 1 START PART 2
+	sums = collections.defaultdict(int)
+	for x in xs:
+		seen: set[Diff] = set()
+		dq: Deque[int] = collections.deque(maxlen=4)
+
+		gen = map(lastdigit, secrets(x))
+		last = next(gen)
+
+		for _ in range(3):
+			n = next(gen)
+			dq.append(n - last)
+			last = n
+
+		for n in gen:
+			dq.append(n - last)
+			if (t := tuple(dq)) not in seen:
+				seen.add(t)
+				sums[t] += n
+			last = n
+			dq.popleft()
+
+	print(max(sums.values()))
+	# END PART 2
+
+
+def secrets(n: int) -> int:
+	for _ in range(2000):
+		n = (n ^ n<<6)	& 0xFFFFFF
+		n = (n ^ n>>5)	& 0xFFFFFF
+		n = (n ^ n<<11) & 0xFFFFFF
+		yield n
+
+
+def lastdigit(n: int) -> int:
+	return n % 10
+
+
+def lastfrom[T](xs: Iterable[T]) -> T:
+	*_, x = xs
+	return x
+
+
+if __name__ == "__main__":
+	main()
-- 
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