2022 - Day 22 (part 1)

Author: Benbb96

python/2022/day22/day22.py

@@ -0,0 +1,122 @@
+import re
+
+from python.download_input import get_input_content
+
+
+turn_right = {
+    'R': 'D',
+    'D': 'L',
+    'L': 'U',
+    'U': 'R'
+}
+
+turn_left = {
+    'R': 'U',
+    'U': 'L',
+    'L': 'D',
+    'D': 'R'
+}
+
+
+def first(board, path):
+    pos_x = pos_y = None
+    direction = 'R'
+    tiles = []
+    walls = []
+
+    for y, line in enumerate(board):
+        for x, cell in enumerate(line):
+            if cell == ' ':
+                continue
+            tiles.append((x, y))
+            if cell == '.':
+                # Set starting position at first tiles seen
+                if pos_x is None and pos_y is None:
+                    pos_x = x
+                    pos_y = y
+            if cell == '#':
+                walls.append((x, y))
+
+    # Read path
+    for instruction in re.findall(r'(\d+|[RL])', path):
+        try:
+            steps = int(instruction)
+        except ValueError:
+            match instruction:
+                case 'R': direction = turn_right[direction]
+                case 'L': direction = turn_left[direction]
+                case _: raise ValueError(f'{instruction} not recognized')
+        else:
+            for i in range(steps):
+                # Find next_position
+                next_x = pos_x
+                next_y = pos_y
+                match direction:
+                    case 'R':
+                        next_x += 1
+                        if (next_x, next_y) not in tiles:
+                            next_x = 0
+                            while (next_x, next_y) not in tiles:
+                                next_x += 1
+                    case 'D':
+                        next_y += 1
+                        if (next_x, next_y) not in tiles:
+                            next_y = 0
+                            while (next_x, next_y) not in tiles:
+                                next_y += 1
+                    case 'L':
+                        next_x -= 1
+                        if (next_x, next_y) not in tiles:
+                            next_x = len(board[0])
+                            while (next_x, next_y) not in tiles:
+                                next_x -= 1
+                    case 'U':
+                        next_y -= 1
+                        if (next_x, next_y) not in tiles:
+                            next_y = len(board)
+                            while (next_x, next_y) not in tiles:
+                                next_y -= 1
+
+                # Check if it is a wall
+                if (next_x, next_y) in walls:
+                    # Stop here
+                    break
+
+                # Check if it is a tile
+                if (next_x, next_y) in tiles:
+                    # Go forward
+                    pos_x = next_x
+                    pos_y = next_y
+
+    return 1000 * (pos_y + 1) + 4 * (pos_x + 1) + 'RDLU'.index(direction)
+
+
+def second(board, path):
+    return 2
+
+
+if __name__ == "__main__":
+    content = get_input_content(__file__, split_by_lines=False)
+    test_input = '''        ...#
+        .#..
+        #...
+        ....
+...#.......#
+........#...
+..#....#....
+..........#.
+        ...#....
+        .....#..
+        .#......
+        ......#.
+
+10R5L5R10L4R5L5'''
+    # if test_input:
+    #     content = test_input\
+
+    board, path = content.split('\n\n')
+    board = board.split('\n')
+
+    print(f'Le résultat de la première partie est :\n{first(board, path)}')
+
+    print(f'Le résultat de la deuxième partie est :\n{second(board, path)}')