Day4 2024 finished

2024/src/day4.py

@@ -0,0 +1,83 @@
+from common import *
+
+DAY_NUMBER = 4
+USE_EXAMPLE = False
+
+ALL_DIRECTIONS = [
+    (0, 1),
+    (1, 0),
+    (1, 1),
+    (1, -1),
+    (-1, 1),
+    (-1, -1),
+    (0, -1),
+    (-1, 0),
+]
+XMAS_SHAPES = [
+    "MMASS",
+    "MSAMS",
+    "SMASM",
+    "SSAMM",
+]
+WORD = "XMAS"
+
+with get_data(DAY_NUMBER, USE_EXAMPLE) as f:
+    board = [l.strip() for l in f.readlines()]
+
+
+def get_value_if_exists(x, y):
+    if x < 0 or y < 0 or x >= len(board) or y >= len(board[0]):
+        return None
+
+    return board[y][x]
+
+
+def part_one():
+    count = 0
+    for x in range(len(board)):
+        for y in range(len(board[0])):
+            if board[y][x] != WORD[0]:
+                continue
+
+            for direction in ALL_DIRECTIONS:
+                created_word = WORD[0]
+                for i in range(1, len(WORD)):
+                    next_value = get_value_if_exists(
+                        x + i * direction[0], y + i * direction[1]
+                    )
+                    if next_value != WORD[i]:
+                        break
+
+                    created_word += next_value
+
+                if created_word == WORD:
+                    count += 1
+
+    return count
+
+
+def get_x_shape(x, y):
+    return (
+        board[y][x]
+        + board[y][x + 2]
+        + board[y + 1][x + 1]
+        + board[y + 2][x]
+        + board[y + 2][x + 2]
+    )
+
+
+def is_a_xmas_shape(shape):
+    return any(shape == xmas_shape for xmas_shape in XMAS_SHAPES)
+
+
+def part_two():
+    count = 0
+    for y in range(len(board[0]) - 2):
+        for x in range(len(board) - 2):
+            if is_a_xmas_shape(get_x_shape(x, y)):
+                count += 1
+    return count
+
+
+print_result(DAY_NUMBER, 1, part_one())
+print_result(DAY_NUMBER, 2, part_two())