some more solutions

2025/day04.py

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+"""Day X: Advent of Code 2025."""
+
+import time
+from aoc import read_lines, read_input, read_grid, read_ints
+import numpy as np
+
+from aoc.helpers import DIRS_8
+
+def neighbors(grid, row, col, dirs=DIRS_8):
+    """Yield (row, col, value) for valid neighbors."""
+    rows, cols = grid.shape
+    for dr, dc in dirs:
+        nr, nc = row + dr, col + dc
+        if 0 <= nr < rows and 0 <= nc < cols:
+            yield nr, nc, grid[nr, nc]
+
+
+def part1(data: np.ndarray):
+    sum = 0
+    for row, col in np.ndindex(data.shape):
+        if data[row, col] != '@':
+            continue
+        l = list(neighbors(data, row, col))
+        ats = len(list(filter(lambda x: x[2] == '@', l)))
+        if ats < 4:
+           sum += 1
+            
+
+    return sum
+
+def part2(data: np.ndarray):
+    sum = 0
+    past_array = np.array([['']*data.shape[1]]*data.shape[0])
+    
+    while not np.equal(data, past_array).all():
+        past_array = data.copy()
+        for row, col in np.ndindex(data.shape):
+            if data[row, col] != '@':
+                continue
+            l = list(neighbors(data, row, col))
+            ats = len(list(filter(lambda x: x[2] == '@', l)))
+            if ats < 4:
+                sum += 1
+                data[row, col] = '-'
+                print(data)
+
+    return sum
+
+if __name__ == "__main__":
+    DAY = 4
+    data = read_grid(DAY)
+
+    t0 = time.perf_counter()
+    p1 = part1(data)
+    t1 = time.perf_counter()
+    print(f"Part 1: {p1}  ({(t1-t0)*1000:.2f} ms)")
+
+    t0 = time.perf_counter()
+    p2 = part2(data)
+    t1 = time.perf_counter()
+    print(f"Part 2: {p2}  ({(t1-t0)*1000:.2f} ms)")