Solve 2025 day 4 pt 1-2

Had a bug in my aoc lib, that lost me an hour for pt 1:
The ADJ dict has SW twice, and lacks NE.

The bug is at least 2 years old. It was introduced in 661f18dca4
and apparently has never worked. I guess it has not been used
up until now.

That being said, it was straight-forward. A new helper for
grid was used the first time, as well as an improved vdbg()
function.

2025-python/aoc.py

@@ -114,5 +114,5 @@ for i in [str(n).zfill(2) for n in range(1, 26)]:
             pass
 if not day_no:
     print(f"\nStars: {stars}")
-    print("".join("*" if n < stars else "•" for n in range(50)))
+    print("".join("*" if n < stars else "•" for n in range(24)))
 print("")

2025-python/output/__init__.py

@@ -34,7 +34,7 @@ DDa = {
 ADJ = [
     (-1, -1),
     (-1, 0),
-    (1, -1),
+    (-1, 1),
     (0, -1),
     (0, 1),
     (1, 1),
@@ -60,6 +60,12 @@ def mhd(a, b):
     return abs(ar - br) + abs(ac - bc)
 
 
+def grid(d, o="#"):
+    """Transform a string into an iterable matrix. Returns the matrix, row count and col count"""
+    m = [tuple(r) for r in d.split()]
+    return set([(r, c) for c in range(len(m[0])) for r in range(len(m)) if m[r][c] == o])
+
+
 def matrix(d):
     """Transform a string into an iterable matrix. Returns the matrix, row count and col count"""
     m = [tuple(r) for r in d.split()]
@@ -72,10 +78,12 @@ def mdbg(m):
         print("".join(r))
 
 
-def vdbg(seen, h, w):
+def vdbg(seen, h, w, C="#", M=None):
     """Print-debug visited positions of a matrix"""
+    def _m(r, c):
+        return M[r][c] if M else "."
     for r in range(h):
-        print("".join(["#" if (r, c) in seen else " " for c in range(w)]))
+        print("".join([C if (r, c) in seen else _m(r, c) for c in range(w)]))
 
 
 def vvdbg(seen, h, w):

2025-python/output/day_04.py

@@ -0,0 +1,31 @@
+from output import grid, ADJ
+
+
+def solve(data):
+    p1 = 0
+    p2 = set()
+    G = grid(data, o="@")
+    while True:
+        for r, c in G:
+            if sum((r + dy, c + dx) in G for dy, dx in ADJ) < 4:
+                p2.add((r, c))
+        if p1 == 0:
+            p1 = len(p2)
+        if not G & p2:
+            break
+        G = G - p2
+    p2 = len(p2)
+    return p1, p2
+
+
+if __name__ == "__main__":
+    with open("./input/04.txt", "r") as f:
+        inp = f.read().strip()
+
+    p1, p2 = solve(inp)
+
+    print(p1)
+    print(p2)
+
+    assert p1 == 1493
+    assert p2 == 9194