From f0fdbb6161528b1af75479a7833251713fd4ea9b Mon Sep 17 00:00:00 2001
From: Armin Friedl <dev@friedl.net>
Date: Sat, 7 Dec 2024 07:58:09 +0100
Subject: [PATCH] Day07

---
 day07.py | 41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 day07.py

diff --git a/day07.py b/day07.py
new file mode 100644
index 0000000..f0967af
--- /dev/null
+++ b/day07.py
@@ -0,0 +1,41 @@
+#!/usr/bin/env python3
+from copy import copy
+
+puzzle = []
+with open("day07") as f:
+    for l in f:
+        (res, n) = l.split(':')
+        ns = list(map(int, n.strip().split(' ')))
+        puzzle.append((int(res), ns))
+
+# 1
+def calc(res, ns, cur):
+    if cur == res: return True
+    if cur > res: return False
+    if len(ns) == 0: return False
+
+    n = ns.pop(0)
+    return calc(res, copy(ns), cur+n) or calc(res, copy(ns), cur*n)
+
+res = 0
+for p in puzzle:
+    if calc(p[0], copy(p[1][1:]), p[1][0]):
+        res += p[0]
+print(res)
+
+# 2
+def calc2(res, ns, cur):
+    if len(ns) == 0 and res == cur: return True
+    if cur > res: return False
+    if len(ns) == 0: return False
+
+    n = ns[0]
+    return (calc2(res, copy(ns[1:]), cur+n)
+            or calc2(res, copy(ns[1:]), cur*n)
+            or calc2(res, copy(ns[1:]), int(str(cur)+str(n))))
+
+res = 0
+for p in puzzle:
+    if calc2(p[0], copy(p[1][1:]), p[1][0]):
+        res += p[0]
+print(res)