1 files changed, 47 insertions, 0 deletions
diff --git a/2024/04/python/main.py b/2024/04/python/main.py
new file mode 100644
index 0000000..a16a943
--- /dev/null
+++ b/2024/04/python/main.py
@@ -0,0 +1,47 @@
+import sys
+
+with open(sys.argv[1], "r") as f:
+    grid = [line.strip() for line in f]
+
+min_x = 0
+min_y = 0
+max_x = len(grid)
+max_y = len(grid[0])
+
+
+def count_xmas(sx, sy):
+    total = 0
+    for dx in [-1, 0, 1]:
+        for dy in [-1, 0, 1]:
+            for n, char in enumerate("XMAS"):
+                x = sx + n * dx
+                y = sy + n * dy
+                if not (min_x <= x < max_x and min_y <= y < max_y):
+                    break
+                if grid[x][y] != char:
+                    break
+            else:
+                total += 1
+    return total
+
+
+def count_x_mas(sx, sy):
+    if sx == min_x or sx == max_x - 1 or sy == min_y or sy == max_y - 1:
+        return 0
+    if grid[sx][sy] != "A":
+        return 0
+    mmss = "".join(
+        (
+            grid[sx - 1][sy - 1],
+            grid[sx - 1][sy + 1],
+            grid[sx + 1][sy + 1],
+            grid[sx + 1][sy - 1],
+        ),
+    )
+    return mmss in {"MMSS", "MSSM", "SSMM", "SMMS"}
+
+
+silver = sum(count_xmas(x, y) for x in range(max_x) for y in range(max_y))
+gold = sum(count_x_mas(x, y) for x in range(max_x) for y in range(max_y))
+print("silver:", silver)
+print("gold:", gold)