solve day 4 part 2

day_04/program.py

@@ -47,11 +47,32 @@ def get_xmas_appearances(grid: list) -> int:
         for col in range(len(grid[0])):
             for direction in directions:
                 if check_xmas_from_pos(grid, row, col, direction, xmas_letters):
-                    print(f"Found XMAS at position ({row}, {col}) in direction {direction}")
+                    # print(f"Found XMAS at position ({row}, {col}) in direction {direction}")
                     xmas_appearances += 1
     return xmas_appearances
 
 
+def check_cross(grid: list, row: int, col: int) -> bool:
+    a1 = grid[row - 1][col - 1]
+    a2 = grid[row + 1][col + 1]
+    b1 = grid[row - 1][col + 1]
+    b2 = grid[row + 1][col - 1]
+    if (a1 == "M" and a2 == "S") or (a1 == "S" and a2 == "M"):
+        if (b1 == "M" and b2 == "S") or (b1 == "S" and b2 == "M"):
+            return True
+    return False
+
+
+def get_cross_mas_appearances(grid: list) -> int:
+    cross_mas_appearances = 0
+    for row in range(1, len(grid) - 1):
+        for col in range(1, len(grid[0]) - 1):
+            if grid[row][col] == "A":
+                if check_cross(grid, row, col):
+                    cross_mas_appearances += 1
+    return cross_mas_appearances
+
+
 def main():
     # lines = get_lines("sample-input.txt")
     lines = get_lines("input.txt")
@@ -59,6 +80,9 @@ def main():
     grid = get_grid(lines)
     xmas_appearances = get_xmas_appearances(grid)
     print(f"Part 1: The word XMAS appears {xmas_appearances} times.")
+    cross_mas_appearances = get_cross_mas_appearances(grid)
+    print(f"Part 2: The cross-MAS pattern appears {cross_mas_appearances} times.")
+
 
 if __name__ == '__main__':
     main()