From 137880a94d619fc4d33e9203c119908b0dca5cb0 Mon Sep 17 00:00:00 2001
From: Sebastian Mark <smark@posteo.net>
Date: Wed, 11 Dec 2024 10:33:54 +0100
Subject: [PATCH] add 2024/day11

---
 2024/11/main.py | 51 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)
 create mode 100644 2024/11/main.py

diff --git a/2024/11/main.py b/2024/11/main.py
new file mode 100644
index 0000000..eeb3a88
--- /dev/null
+++ b/2024/11/main.py
@@ -0,0 +1,51 @@
+#!/usr/bin/env python
+# -*- encoding: utf-8; py-indent-offset: 4 -*-
+
+# Author: Sebastian Mark
+# CC-BY-SA (https://creativecommons.org/licenses/by-sa/4.0/deed.de)
+
+# pylint: disable=missing-module-docstring,missing-function-docstring,consider-using-f-string
+
+
+def readinput():
+    with open("input", "r", encoding="utf-8") as file:
+        # initialize with a count of 1 for each number
+        stones = {int(n): 1 for n in file.readline().split()}
+    return stones
+
+
+def blink(stone: str) -> list:
+    if stone == 0:
+        return [1]
+
+    if len(str(stone)) % 2 == 0:
+        middle = len(str(stone)) // 2
+        first = str(stone)[:middle]
+        second = str(stone)[middle:]
+        return [int(first), int(second)]
+
+    return [int(stone) * 2024]
+
+
+def solve(stones: dict) -> dict:
+    new_stones = {}
+
+    for stone, count in stones.items():
+        for num in blink(stone):
+            # count of each number, remember existing occurences
+            new_stones[num] = new_stones.get(num, 0) + count
+
+    return new_stones
+
+
+def main():
+    # part 1 + 2
+    for r in [25, 75]:
+        stones = readinput()
+        for _ in range(r):
+            stones = solve(stones)
+        print("Number of stones (%d blinks): %d" % (r, sum(stones.values())))
+
+
+if __name__ == "__main__":
+    main()