From eb233235c876600bafa39a538d18ce11cfc72b39 Mon Sep 17 00:00:00 2001
From: Sebastiano Tronto <sebastiano@tronto.net>
Date: Sun, 7 Dec 2025 09:14:27 +0100
Subject: Clean up and alternative solution to day 7

---
 2025/07/a.py  |  2 +-
 2025/07/b.py  |  2 +-
 2025/07/b2.py | 17 +++++++++++++++++
 3 files changed, 19 insertions(+), 2 deletions(-)
 create mode 100644 2025/07/b2.py

(limited to '2025/07')

diff --git a/2025/07/a.py b/2025/07/a.py
index 0e13b75..53ff68c 100644
--- a/2025/07/a.py
+++ b/2025/07/a.py
@@ -2,9 +2,9 @@ import fileinput
 
 with fileinput.input() as lines:
 	rows = [line[:-1] for line in lines]
-	pos = [rows[0].find('S')]
 
 s = 0
+pos = [rows[0].find('S')]
 for row in rows[1:]:
 	newpos = set()
 	for p in pos:
diff --git a/2025/07/b.py b/2025/07/b.py
index 41c0db0..4457654 100644
--- a/2025/07/b.py
+++ b/2025/07/b.py
@@ -2,8 +2,8 @@ import fileinput
 
 with fileinput.input() as lines:
 	rows = [line[:-1] for line in lines]
-	pos = {rows[0].find('S'): 1}
 
+pos = {rows[0].find('S'): 1}
 for row in rows[1:]:
 	newpos = {}
 	for p, w in pos.items():
diff --git a/2025/07/b2.py b/2025/07/b2.py
new file mode 100644
index 0000000..b77188c
--- /dev/null
+++ b/2025/07/b2.py
@@ -0,0 +1,17 @@
+import fileinput
+
+with fileinput.input() as lines:
+	rows = [line[:-1] for line in lines]
+
+t = [1 if x == 'S' else 0 for x in rows[0]]
+for row in rows[1:]:
+	next = [0] * len(row)
+	for i in range(len(row)):
+		if row[i] == '^':
+			next[i-1] += t[i]
+			next[i+1] += t[i]
+		else:
+			next[i] += t[i]
+	t = next
+
+print(sum(t))
-- 
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