From bf55c705754eae73a1863aca6a9a7d4f06ca6df0 Mon Sep 17 00:00:00 2001
From: Bruno BELANYI <bruno@belanyi.fr>
Date: Wed, 11 Dec 2024 09:16:17 -0500
Subject: [PATCH] 2024: d11: ex2: add solution

---
 2024/d11/ex2/ex2.py | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)
 create mode 100755 2024/d11/ex2/ex2.py

diff --git a/2024/d11/ex2/ex2.py b/2024/d11/ex2/ex2.py
new file mode 100755
index 0000000..e9c5900
--- /dev/null
+++ b/2024/d11/ex2/ex2.py
@@ -0,0 +1,37 @@
+#!/usr/bin/env python
+
+import sys
+from collections import Counter
+
+
+def solve(input: str) -> int:
+    def parse(input: str) -> Counter[int]:
+        return Counter(int(n) for n in input.split())
+
+    def blink(stones: Counter[int]) -> Counter[int]:
+        res: Counter[int] = Counter()
+        for n, count in stones.items():
+            if n == 0:
+                res[1] += count
+            elif len(str(n)) % 2 == 0:
+                s = str(n)
+                lhs, rhs = s[: len(s) // 2], s[len(s) // 2 :]
+                res[int(lhs)] += count
+                res[int(rhs)] += count
+            else:
+                res[n * 2024] += count
+        return res
+
+    stones = parse(input)
+    for _ in range(75):
+        stones = blink(stones)
+    return sum(stones.values())
+
+
+def main() -> None:
+    input = sys.stdin.read()
+    print(solve(input))
+
+
+if __name__ == "__main__":
+    main()