From cc916af0b7d81bc6c03d24dcf71d6ffcae220718 Mon Sep 17 00:00:00 2001
From: Bruno BELANYI <bruno@belanyi.fr>
Date: Sun, 11 May 2025 23:14:23 +0100
Subject: [PATCH] 2017: d23: ex2: add solution

---
 2017/d23/ex2/ex2.py | 55 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)
 create mode 100755 2017/d23/ex2/ex2.py

diff --git a/2017/d23/ex2/ex2.py b/2017/d23/ex2/ex2.py
new file mode 100755
index 0000000..cf18a89
--- /dev/null
+++ b/2017/d23/ex2/ex2.py
@@ -0,0 +1,55 @@
+#!/usr/bin/env python
+
+import enum
+import math
+import sys
+from typing import NamedTuple
+
+
+class Op(enum.StrEnum):
+    SET = "set"
+    SUB = "sub"
+    MUL = "mul"
+    JNZ = "jnz"
+
+
+class Instruction(NamedTuple):
+    op: Op
+    x: str
+    y: str
+
+    @classmethod
+    def from_str(cls, input: str) -> "Instruction":
+        op, *rest = input.split()
+        return cls(Op(op), *rest)
+
+
+def solve(input: str) -> int:
+    def parse(input: str) -> list[Instruction]:
+        return [Instruction.from_str(line) for line in input.splitlines()]
+
+    def is_prime(n: int) -> bool:
+        if n % 2 == 0:
+            return False
+        for i in range(3, math.isqrt(n), 2):
+            if n % i == 0:
+                return False
+        return True
+
+    instructions = parse(input)
+    start = int(instructions[0].y) * 100 + 100000
+    end = start + 17000
+
+    total = 0
+    for n in range(start, end + 1, 17):
+        total += not is_prime(n)
+    return total
+
+
+def main() -> None:
+    input = sys.stdin.read()
+    print(solve(input))
+
+
+if __name__ == "__main__":
+    main()