Day 7 2025

2 files changed, 30 insertions, 2 deletions

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()))