Jake Pullen
66 lines
1.9 KiB
Python
66 lines
1.9 KiB
Python
testing = 0
|
|
if not testing:
|
|
with open(r"2024/06\input.txt", "r") as file:
|
|
input = file.read()
|
|
else:
|
|
input = """....#.....
|
|
.........#
|
|
..........
|
|
..#.......
|
|
.......#..
|
|
..........
|
|
.#..^.....
|
|
........#.
|
|
#.........
|
|
......#..."""
|
|
|
|
OBSTACLE = "#"
|
|
# first we should turn the input into a list of lists so we can use grid references
|
|
|
|
input = input.split("\n")
|
|
grid = [list(x) for x in input]
|
|
|
|
# for x in grid:
|
|
# print(x)
|
|
|
|
# we need to find the starting position
|
|
# our starting position is the only '^' in the grid
|
|
for x in range(len(grid)):
|
|
for y in range(len(grid[x])):
|
|
if grid[x][y] == "^":
|
|
position = (x, y)
|
|
break
|
|
print('start at',position)
|
|
|
|
# We start by travelling north until we hit an obstacle '#'
|
|
# then we turn right and travel east until we hit an obstacle
|
|
# we keep turning right and travelling until we hit an obstacle
|
|
# once we make it off the grid we stop
|
|
# count how many unique squares we visit
|
|
|
|
def count_unique_squares(grid, start):
|
|
directions = [(-1, 0), (0, 1), (1, 0), (0, -1)] # North, East, South, West
|
|
direction_index = 0 # Start by moving north
|
|
x, y = start
|
|
visited = set()
|
|
|
|
while True:
|
|
visited.add((x, y))
|
|
dx, dy = directions[direction_index]
|
|
new_x, new_y = x + dx, y + dy
|
|
# if new position is off the grid, we stop
|
|
if (new_x < 0 or new_x >= len(grid) or new_y < 0 or new_y >= len(grid[0])):
|
|
print(f"Moved off the grid to ({new_x}, {new_y}), stopping")
|
|
break
|
|
# if we hit an obstacle, we turn right
|
|
elif grid[new_x][new_y] == OBSTACLE:
|
|
direction_index = (direction_index + 1) % 4 # Turn right
|
|
print(f"Hit obstacle at ({new_x}, {new_y}), turning right to direction {directions[direction_index]}")
|
|
|
|
else:
|
|
x, y = new_x, new_y
|
|
print(f"Moved to ({x}, {y})")
|
|
|
|
return len(visited)
|
|
|
|
print(count_unique_squares(grid, position)) |