From aa7ddad8c6949b5dfb7a4c77b49c5e65ae5aa782 Mon Sep 17 00:00:00 2001
From: Sebastiano Tronto <sebastiano@tronto.net>
Date: Sun, 7 Dec 2025 06:34:41 +0100
Subject: Day 7 2025

---
 2025/07/a.py | 17 +++++++++++++++--
 2025/07/b.py | 15 +++++++++++++++
 2 files changed, 30 insertions(+), 2 deletions(-)
 create mode 100644 2025/07/b.py

(limited to '2025/07')

diff --git a/2025/07/a.py b/2025/07/a.py
index 5fdb11b..0e13b75 100644
--- a/2025/07/a.py
+++ b/2025/07/a.py
@@ -1,6 +1,19 @@
 import fileinput
 
 with fileinput.input() as lines:
-	for line in lines:
-		...
+	rows = [line[:-1] for line in lines]
+	pos = [rows[0].find('S')]
 
+s = 0
+for row in rows[1:]:
+	newpos = set()
+	for p in pos:
+		if row[p] == '^':
+			s += 1
+			newpos.add(p-1)
+			newpos.add(p+1)
+		else:
+			newpos.add(p)
+	pos = list(newpos)
+
+print(s)
diff --git a/2025/07/b.py b/2025/07/b.py
new file mode 100644
index 0000000..41c0db0
--- /dev/null
+++ b/2025/07/b.py
@@ -0,0 +1,15 @@
+import fileinput
+
+with fileinput.input() as lines:
+	rows = [line[:-1] for line in lines]
+	pos = {rows[0].find('S'): 1}
+
+for row in rows[1:]:
+	newpos = {}
+	for p, w in pos.items():
+		for pp in [p-1,p+1] if row[p] == '^' else [p]:
+			t = newpos.get(pp, 0)
+			newpos[pp] = t + w
+	pos = dict(newpos)
+
+print(sum(pos.values()))
-- 
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