class Maze():
def __init__(self, filename):
# Read file and set height and width of maze
with open(filename) as f:
contents = f.read()
# Validate start and goal
if contents.count("A") != 1:
raise Exception("maze must have exactly one start point")
if contents.count("B") != 1:
raise Exception("maze must have exactly one goal")
# Determine height and width of maze
contents = contents.splitlines()
self.height = len(contents)
self.width = max(len(line) for line in contents)
# Keep track of walls
self.walls = []
for i in range(self.height):
row = []
for j in range(self.width):
try:
if contents[i][j] == "A":
self.start = (i, j)
row.append(False)
elif contents[i][j] == "B":
self.goal = (i, j)
row.append(False)
elif contents[i][j] == " ":
row.append(False)
else:
row.append(True)
except IndexError:
row.append(False)
self.walls.append(row)
self.solution = None
def print(self):
solution = self.solution[1] if self.solution is not None else None
print()
for i, row in enumerate(self.walls):
for j, col in enumerate(row):
if col:
print("█", end="")
elif (i, j) == self.start:
print("A", end="")
elif (i, j) == self.goal:
print("B", end="")
elif solution is not None and (i, j) in solution:
print("*", end="")
else:
print(" ", end="")
print()
print()
def neighbors(self, state):
row, col = state
candidates = [
("up", (row - 1, col)),
("down", (row + 1, col)),
("left", (row, col - 1)),
("right", (row, col + 1))
]
result = []
for action, (r, c) in candidates:
if 0 <= r < self.height and 0 <= c < self.width and not self.walls[r][c]:
result.append((action, (r, c)))
return result