From 525c6aa96cd6fc70fb1e0792cf194b309033405e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Anders=20Engl=C3=B6f=20Ytterstr=C3=B6m?= <yttan@fastmail.se>
Date: Wed, 11 Dec 2024 23:25:50 +0100
Subject: [PATCH] Solve 2016:23 p1-2 "Safe Cracking"

Solution cide works, but is slow. According to the
subreddit, pt 2 is meant to be an exercise in
optimization.

Turns out the assembly instructions do a factorial,
i.e 7! and 12! and adds a salt (5840).

Got that spoiled. :)
---
 2016-python2/output/day_23.py | 76 +++++++++++++++++++++++++++++++++++
 1 file changed, 76 insertions(+)
 create mode 100644 2016-python2/output/day_23.py

diff --git a/2016-python2/output/day_23.py b/2016-python2/output/day_23.py
new file mode 100644
index 0000000..d7d3e59
--- /dev/null
+++ b/2016-python2/output/day_23.py
@@ -0,0 +1,76 @@
+def solve(data):
+    p = data.splitlines()
+    # math.factorial(7) + 5840
+    p1 = run(
+        p.copy(),
+        {
+            "a": 7,
+            "b": 0,
+            "c": 0,
+            "d": 0,
+        },
+    )
+    # math.factorial(12) + 5840
+    p2 = run(
+        p.copy(),
+        {
+            "a": 12,
+            "b": 0,
+            "c": 0,
+            "d": 0,
+        },
+    )
+    return p1, p2
+
+
+def run(p, r):
+    i = 0
+    pl = len(p)
+    while i < pl:
+        o, *a = p[i].split()
+        match o:
+            case "cpy":
+                kv, t = a
+                if t in "abcd":
+                    r[t] = int(kv) if kv not in "abcd" else r[kv]
+                i += 1
+            case "jnz":
+                kv, d = a
+                c = int(kv) if kv not in "abcd" else r[kv]
+                d = int(d) if d not in "abcd" else r[d]
+                i += 1 if c == 0 else d
+            case "inc":
+                r[a[0]] += 1
+                i += 1
+            case "dec":
+                r[a[0]] -= 1
+                i += 1
+            case "tgl":
+                kv = a[0]
+                c = int(kv) if kv not in "abcd" else r[kv]
+                if 0 <= i + c < pl:
+                    old, *v = p[i + c].split()
+                    match old:
+                        case "inc":
+                            nw = "dec"
+                        case "dec":
+                            nw = "inc"
+                        case "tgl":
+                            nw = "inc"
+                        case "jnz":
+                            nw = "cpy"
+                        case _:
+                            nw = "jnz"
+                    p[i + c] = " ".join([nw] + v)
+                i += 1
+    return r["a"]
+
+
+if __name__ == "__main__":
+    with open("./input/23.txt", "r") as f:
+        inp = f.read().strip()
+
+    p1, p2 = solve(inp)
+
+    print(p1)
+    print(p2)