doing the wheel

This commit is contained in:
maoake
2026-04-01 22:31:08 +02:00
parent be997c5d17
commit 2edf61affa
13 changed files with 58 additions and 55 deletions
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from dataclasses import dataclass
@dataclass
class Cell:
"""Represent a maze cell encoded as a bitmask of surrounding walls.
The cell value is stored as an integer where each bit represents the
presence of a wall in one cardinal direction:
- bit 0 (1): north wall
- bit 1 (2): east wall
- bit 2 (4): south wall
- bit 3 (8): west wall
"""
def __init__(self, value: int) -> None:
"""Initialize a cell with its encoded wall value.
Args:
value: Integer bitmask representing the cell walls.
"""
self.value = value
def __str__(self) -> str:
"""Return the hexadecimal representation of the cell value.
Returns:
The uppercase hexadecimal form of the cell value without the
``0x`` prefix.
"""
return hex(self.value).removeprefix("0x").upper()
def set_value(self, value: int) -> None:
"""Set the encoded value of the cell.
Args:
value: Integer bitmask representing the cell walls.
"""
self.value = value
def get_value(self) -> int:
"""Return the encoded value of the cell.
Returns:
The integer bitmask representing the cell walls.
"""
return self.value
def set_north(self, is_wall: bool) -> None:
"""Set or clear the north wall.
Args:
is_wall: ``True`` to add the north wall, ``False`` to remove it.
"""
if (not is_wall and self.value | 14 == 15) or (
is_wall and self.value | 14 != 15
):
self.value = self.value ^ (1)
def get_north(self) -> bool:
"""Return whether the north wall is present.
Returns:
``True`` if the north wall is set, otherwise ``False``.
"""
return self.value & 1 == 1
def set_est(self, is_wall: bool) -> None:
"""Set or clear the east wall.
Args:
is_wall: ``True`` to add the east wall, ``False`` to remove it.
"""
if (not is_wall and self.value | 13 == 15) or (
is_wall and self.value | 13 != 15
):
self.value = self.value ^ (2)
def get_est(self) -> bool:
"""Return whether the east wall is present.
Returns:
``True`` if the east wall is set, otherwise ``False``.
"""
return self.value & 2 == 2
def set_south(self, is_wall: bool) -> None:
"""Set or clear the south wall.
Args:
is_wall: ``True`` to add the south wall, ``False`` to remove it.
"""
if (not is_wall and self.value | 11 == 15) or (
is_wall and self.value | 11 != 15
):
self.value = self.value ^ (4)
def get_south(self) -> bool:
"""Return whether the south wall is present.
Returns:
``True`` if the south wall is set, otherwise ``False``.
"""
return self.value & 4 == 4
def set_west(self, is_wall: bool) -> None:
"""Set or clear the west wall.
Args:
is_wall: ``True`` to add the west wall, ``False`` to remove it.
"""
if (not is_wall and self.value | 7 == 15) or (
is_wall and self.value | 7 != 15
):
self.value = self.value ^ (8)
def get_west(self) -> bool:
"""Return whether the west wall is present.
Returns:
``True`` if the west wall is set, otherwise ``False``.
"""
return self.value & 8 == 8
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from dataclasses import dataclass
from numpy.typing import NDArray
from typing import Optional, Any
@dataclass
class Maze:
"""Represent a maze as a two-dimensional array of cells."""
maze: Optional[NDArray[Any]] = None
def get_maze(self) -> Optional[NDArray[Any]]:
"""Return the underlying maze array.
Returns:
The two-dimensional array representing the maze, or ``None`` if no
maze has been set.
"""
return self.maze
def set_maze(self, new_maze: NDArray[Any]) -> None:
"""Set the maze array.
Args:
new_maze: A two-dimensional array containing the maze cells.
"""
self.maze = new_maze
def __str__(self) -> str:
"""Return a string representation of the maze.
Each cell is converted to its string representation and concatenated
line by line.
Returns:
A multiline string representation of the maze, or ``"None"`` if the
maze is not set.
"""
if self.maze is None:
return "None"
res = ""
for line in self.maze:
for cell in line:
res += cell.__str__()
res += "\n"
return res
def ascii_print(self) -> None:
"""Print an ASCII representation of the maze.
The maze is rendered using underscores and vertical bars to show the
walls of each cell. If no maze is set, ``"None"`` is printed.
"""
if self.maze is None:
print("None")
return
for cell in self.maze[0]:
print("_", end="")
if cell.get_north():
print("__", end="")
else:
print(" ", end="")
print("_")
for line in self.maze:
for cell in line:
if cell is line[0] and cell.get_west():
print("|", end="")
if cell.get_south() is True:
print("__", end="")
else:
print(" ", end="")
if cell.get_est() is True:
print("|", end="")
else:
print("_", end="")
print()
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from abc import ABC, abstractmethod
from typing import Generator, Any
import numpy as np
from numpy.typing import NDArray
from .Cell import Cell
import math
import random
class MazeGenerator(ABC):
"""Define the common interface and helpers for maze generators."""
def __init__(
self, start: tuple[int, int], end: tuple[int, int], perfect: bool
) -> None:
"""Initialize the maze generator.
Args:
start: Starting cell coordinates, using 1-based indexing.
end: Ending cell coordinates, using 1-based indexing.
perfect: Whether to generate a perfect maze with no loops.
"""
self.start = (start[0] - 1, start[1] - 1)
self.end = (end[0] - 1, end[1] - 1)
self.perfect = perfect
@abstractmethod
def generator(
self, height: int, width: int, seed: int | None = None
) -> Generator[NDArray[Any], None, NDArray[Any]]:
"""Generate a maze step by step.
Args:
height: Number of rows in the maze.
width: Number of columns in the maze.
seed: Optional random seed for reproducibility.
Yields:
Intermediate maze states during generation.
Returns:
The final generated maze.
"""
...
@staticmethod
def get_cell_ft(width: int, height: int) -> set[tuple[int, int]]:
"""Return the coordinates used to reserve the '42' pattern.
Args:
width: Number of columns in the maze.
height: Number of rows in the maze.
Returns:
A set of cell coordinates belonging to the reserved pattern.
"""
forty_two = set()
y, x = (int(height / 2), int(width / 2))
forty_two.add((y, x - 1))
forty_two.add((y, x - 2))
forty_two.add((y, x - 3))
forty_two.add((y - 1, x - 3))
forty_two.add((y - 2, x - 3))
forty_two.add((y + 1, x - 1))
forty_two.add((y + 2, x - 1))
forty_two.add((y, x + 1))
forty_two.add((y, x + 2))
forty_two.add((y, x + 3))
forty_two.add((y - 1, x + 3))
forty_two.add((y - 2, x + 3))
forty_two.add((y - 2, x + 2))
forty_two.add((y - 2, x + 1))
forty_two.add((y + 1, x + 1))
forty_two.add((y + 2, x + 1))
forty_two.add((y + 2, x + 2))
forty_two.add((y + 2, x + 3))
return forty_two
@staticmethod
def unperfect_maze(
width: int,
height: int,
maze: NDArray[Any],
forty_two: set[tuple[int, int]] | None,
prob: float = 0.1,
) -> Generator[NDArray[Any], None, NDArray[Any]]:
"""Add extra openings to transform a perfect maze into an imperfect
one.
Random walls are removed while optionally preserving the reserved
``forty_two`` area.
Args:
width: Number of columns in the maze.
height: Number of rows in the maze.
maze: The maze to modify.
forty_two: Optional set of reserved coordinates that must not be
altered.
prob: Probability of breaking an eligible wall.
Yields:
Intermediate maze states after each wall removal.
Returns:
The modified maze.
"""
directions = {"N": (0, -1), "S": (0, 1), "W": (-1, 0), "E": (1, 0)}
reverse = {"N": "S", "S": "N", "W": "E", "E": "W"}
min_break = 2
while True:
count = 0
for y in range(height):
for x in range(width):
if forty_two and (x, y) in forty_two:
continue
for direc, (dx, dy) in directions.items():
nx, ny = x + dx, y + dy
if forty_two and (
(y, x) in forty_two or (ny, nx) in forty_two
):
continue
if not (0 <= nx < width and 0 < ny < height):
continue
if direc in ["S", "E"]:
continue
if np.random.random() < prob:
count += 1
cell = maze[y][x]
cell_n = maze[ny][nx]
cell = DepthFirstSearch.broken_wall(cell, direc)
cell_n = DepthFirstSearch.broken_wall(
cell_n,
reverse[direc],
)
maze[y][x] = cell
maze[ny][nx] = cell_n
yield maze
if count > min_break:
break
return maze
class Kruskal(MazeGenerator):
"""Generate a maze using a Kruskal-based algorithm."""
class KruskalSet:
"""Represent a connected component of maze cells."""
def __init__(self, cells: list[int]) -> None:
"""Initialize a set of connected cells.
Args:
cells: List of cell indices belonging to the set.
"""
self.cells: list[int] = cells
class Sets:
"""Store all connected components used during generation."""
def __init__(self, sets: list["Kruskal.KruskalSet"]) -> None:
"""Initialize the collection of connected components.
Args:
sets: List of disjoint cell sets.
"""
self.sets = sets
@staticmethod
def walls_to_maze(
walls: list[tuple[int, int]], height: int, width: int
) -> NDArray[Any]:
"""Convert a list of remaining walls into a maze grid.
Args:
walls: Collection of wall pairs between adjacent cells.
height: Number of rows in the maze.
width: Number of columns in the maze.
Returns:
A two-dimensional array of :class:`Cell` instances representing the
maze.
"""
maze: NDArray[Any] = np.array(
[[Cell(value=0) for _ in range(width)] for _ in range(height)]
)
for wall in walls:
x, y = wall
match y - x:
case 1:
maze[math.trunc((x / width))][x % width].set_est(True)
maze[math.trunc((y / width))][y % width].set_west(True)
case width:
maze[math.trunc((x / width))][x % width].set_south(True)
maze[math.trunc((y / width))][y % width].set_north(True)
for x in range(height):
for y in range(width):
if x == 0:
maze[x][y].set_north(True)
if x == height - 1:
maze[x][y].set_south(True)
if y == 0:
maze[x][y].set_west(True)
if y == width - 1:
maze[x][y].set_est(True)
return maze
@staticmethod
def is_in_same_set(sets: Sets, wall: tuple[int, int]) -> bool:
"""Check whether both cells connected by a wall are in the same set.
Args:
sets: Current collection of connected components.
wall: Pair of adjacent cell indices.
Returns:
``True`` if both cells belong to the same set, otherwise ``False``.
"""
a, b = wall
for set in sets.sets:
if a in set.cells and b in set.cells:
return True
elif a in set.cells or b in set.cells:
return False
return False
@staticmethod
def merge_sets(sets: Sets, wall: tuple[int, int]) -> None:
"""Merge the two sets connected by the given wall.
Args:
sets: Current collection of connected components.
wall: Pair of adjacent cell indices.
Raises:
Exception: If the two corresponding sets cannot be found.
"""
a, b = wall
base_set = None
for i in range(len(sets.sets)):
if base_set is None and (
a in sets.sets[i].cells or b in sets.sets[i].cells
):
base_set = sets.sets[i]
elif base_set and (
a in sets.sets[i].cells or b in sets.sets[i].cells
):
base_set.cells += sets.sets[i].cells
sets.sets.pop(i)
return
raise Exception("two sets not found")
@staticmethod
def touch_ft(
width: int,
wall: tuple[int, int],
cells_ft: None | set[tuple[int, int]],
) -> bool:
"""Check whether a wall touches the reserved '42' pattern.
Args:
width: Number of columns in the maze.
wall: Pair of adjacent cell indices.
cells_ft: Reserved coordinates, or ``None``.
Returns:
``True`` if either endpoint of the wall belongs to the reserved
pattern, otherwise ``False``.
"""
if cells_ft is None:
return False
s1 = (math.trunc(wall[0] / width), wall[0] % width)
s2 = (math.trunc(wall[1] / width), wall[1] % width)
return s1 in cells_ft or s2 in cells_ft
def generator(
self, height: int, width: int, seed: int | None = None
) -> Generator[NDArray[Any], None, NDArray[Any]]:
"""Generate a maze using a Kruskal-based approach.
Args:
height: Number of rows in the maze.
width: Number of columns in the maze.
seed: Optional random seed for reproducibility.
Yields:
Intermediate maze states during generation.
Returns:
The final generated maze.
"""
cells_ft = None
if height > 10 and width > 10:
cells_ft = self.get_cell_ft(width, height)
if cells_ft and (self.start in cells_ft or self.end in cells_ft):
cells_ft = None
if seed is not None:
np.random.seed(seed)
sets = self.Sets([self.KruskalSet([i]) for i in range(height * width)])
walls = []
for h in range(height):
for w in range(width - 1):
walls += [(w + (width * h), w + (width * h) + 1)]
for h in range(height - 1):
for w in range(width):
walls += [(w + (width * h), w + (width * (h + 1)))]
np.random.shuffle(walls)
yield self.walls_to_maze(walls, height, width)
while (len(sets.sets) != 1 and cells_ft is None) or (
len(sets.sets) != 19 and cells_ft is not None
):
for wall in walls:
if not self.is_in_same_set(sets, wall) and not self.touch_ft(
width, wall, cells_ft
):
self.merge_sets(sets, wall)
walls.remove(wall)
yield self.walls_to_maze(walls, height, width)
if (len(sets.sets) == 1 and cells_ft is None) or (
len(sets.sets) == 19 and cells_ft is not None
):
break
print(f"nb sets: {len(sets.sets)}")
maze = self.walls_to_maze(walls, height, width)
if self.perfect is False:
gen = Kruskal.unperfect_maze(width, height, maze, cells_ft)
for res in gen:
maze = res
yield maze
return maze
class DepthFirstSearch(MazeGenerator):
"""Generate a maze using a depth-first search backtracking algorithm."""
def __init__(
self, start: tuple[int, int], end: tuple[int, int], perfect: bool
) -> None:
"""Initialize the depth-first search generator.
Args:
start: Starting cell coordinates, using 1-based indexing.
end: Ending cell coordinates, using 1-based indexing.
perfect: Whether to generate a perfect maze with no loops.
"""
self.start = (start[0] - 1, start[1] - 1)
self.end = (end[0] - 1, end[1] - 1)
self.perfect = perfect
self.forty_two: set[tuple[int, int]] | None = None
def generator(
self, height: int, width: int, seed: int | None = None
) -> Generator[NDArray[Any], None, NDArray[Any]]:
"""Generate a maze using depth-first search.
Args:
height: Number of rows in the maze.
width: Number of columns in the maze.
seed: Optional random seed for reproducibility.
Yields:
Intermediate maze states during generation.
Returns:
The final generated maze.
"""
if seed is not None:
np.random.seed(seed)
maze = self.init_maze(width, height)
if width > 9 and height > 9:
self.forty_two = self.get_cell_ft(width, height)
visited: NDArray[np.object_] = np.zeros((height, width), dtype=bool)
if (
self.forty_two
and self.start not in self.forty_two
and self.end not in self.forty_two
):
visited = self.lock_cell_ft(visited, self.forty_two)
path: list[tuple[int, int]] = list()
w_h = (width, height)
coord = (0, 0)
x, y = coord
first_iteration = True
while path or first_iteration:
first_iteration = False
visited[y, x] = True
path = self.add_cell_visited(coord, path)
random_c = self.random_cells(visited, coord, w_h)
if not random_c:
path = self.back_on_step(path, w_h, visited)
if not path:
break
coord = path[-1]
random_c = self.random_cells(visited, coord, w_h)
x, y = coord
wall = self.next_step(random_c)
maze[y][x] = self.broken_wall(maze[y][x], wall)
coord = self.next_cell(x, y, wall)
wall_r = self.reverse_path(wall)
x, y = coord
maze[y][x] = self.broken_wall(maze[y][x], wall_r)
yield maze
if self.perfect is False:
gen = DepthFirstSearch.unperfect_maze(
width,
height,
maze,
self.forty_two,
)
for res in gen:
maze = res
yield maze
return maze
@staticmethod
def init_maze(width: int, height: int) -> NDArray[Any]:
"""Create a fully walled maze grid.
Args:
width: Number of columns in the maze.
height: Number of rows in the maze.
Returns:
A two-dimensional array of cells initialized with all
walls present.
"""
maze = np.array(
[[Cell(value=15) for _ in range(width)] for _ in range(height)]
)
return maze
@staticmethod
def add_cell_visited(
coord: tuple[int, int], path: list[tuple[int, int]]
) -> list[tuple[int, int]]:
"""Append a visited coordinate to the current traversal path.
Args:
coord: Coordinate of the visited cell.
path: Current traversal path.
Returns:
The updated path.
"""
path.append(coord)
return path
@staticmethod
def random_cells(
visited: NDArray[Any], coord: tuple[int, int], w_h: tuple[int, int]
) -> list[str]:
"""Return the list of unvisited neighboring directions.
Args:
visited: Boolean array marking visited cells.
coord: Current cell coordinate.
w_h: Tuple containing maze width and height.
Returns:
A list of direction strings among ``"N"``, ``"S"``, ``"W"``, and
``"E"``.
"""
rand_cell: list[str] = []
x, y = coord
width, height = w_h
if y - 1 >= 0 and not visited[y - 1][x]:
rand_cell.append("N")
if y + 1 < height and not visited[y + 1][x]:
rand_cell.append("S")
if x - 1 >= 0 and not visited[y][x - 1]:
rand_cell.append("W")
if x + 1 < width and not visited[y][x + 1]:
rand_cell.append("E")
return rand_cell
@staticmethod
def next_step(rand_cell: list[str]) -> str:
"""Select the next direction at random.
Args:
rand_cell: List of candidate directions.
Returns:
A randomly selected direction.
"""
return random.choice(rand_cell)
@staticmethod
def broken_wall(cell: Cell, wall: str) -> Cell:
"""Remove the specified wall from a cell.
Args:
cell: The cell to modify.
wall: Direction of the wall to remove.
Returns:
The modified cell.
"""
if wall == "N":
cell.set_north(False)
elif wall == "S":
cell.set_south(False)
elif wall == "W":
cell.set_west(False)
elif wall == "E":
cell.set_est(False)
return cell
@staticmethod
def next_cell(x: int, y: int, next: str) -> tuple[int, int]:
"""Return the coordinates of the adjacent cell in the given direction.
Args:
x: Current column index.
y: Current row index.
next: Direction to move.
Returns:
The coordinates of the next cell.
"""
next_step = {"N": (0, -1), "S": (0, 1), "W": (-1, 0), "E": (1, 0)}
add_x, add_y = next_step[next]
return (x + add_x, y + add_y)
@staticmethod
def reverse_path(direction: str) -> str:
"""Return the opposite cardinal direction.
Args:
direction: Input direction.
Returns:
The opposite direction.
"""
return {"N": "S", "S": "N", "W": "E", "E": "W"}[direction]
@staticmethod
def back_on_step(
path: list[tuple[int, int]],
w_h: tuple[int, int],
visited: NDArray[Any],
) -> list[tuple[int, int]]:
"""Backtrack through the path until a cell with unvisited neighbors
is found.
Args:
path: Current traversal path.
w_h: Tuple containing maze width and height.
visited: Boolean array marking visited cells.
Returns:
The truncated path after backtracking.
"""
while path:
last = path[-1]
if DepthFirstSearch.random_cells(visited, last, w_h):
break
path.pop()
return path
@staticmethod
def lock_cell_ft(
visited: NDArray[Any], forty_two: set[tuple[int, int]]
) -> NDArray[Any]:
"""Mark the reserved '42' pattern cells as already visited.
Args:
visited: Boolean array marking visited cells.
forty_two: Set of reserved cell coordinates.
Returns:
The updated visited array.
"""
tab = [cell for cell in forty_two]
for cell in tab:
visited[cell] = True
return visited
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from abc import ABC, abstractmethod
from .Maze import Maze
from typing import Any
import numpy as np
from numpy.typing import NDArray
import random
class MazeSolver(ABC):
"""Define the common interface for maze-solving algorithms."""
def __init__(self, start: tuple[int, int], end: tuple[int, int]) -> None:
"""Initialize the maze solver.
Args:
start: Start coordinates using 1-based indexing.
end: End coordinates using 1-based indexing.
"""
self.start = (start[1] - 1, start[0] - 1)
self.end = (end[1] - 1, end[0] - 1)
@abstractmethod
def solve(
self, maze: Maze, height: int | None = None, width: int | None = None
) -> str:
"""Solve the maze and return the path as direction letters.
Args:
maze: The maze to solve.
height: Optional maze height.
width: Optional maze width.
Returns:
A string representing the path using cardinal directions.
"""
...
class AStar(MazeSolver):
"""Solve a maze using the A* pathfinding algorithm."""
class Node:
"""Represent a node used during A* exploration."""
def __init__(
self,
coordinate: tuple[int, int],
g: int,
h: int,
f: int,
parent: Any,
) -> None:
"""Initialize a search node.
Args:
coordinate: Coordinates of the node.
g: Cost from the start node.
h: Heuristic cost to the goal.
f: Total estimated cost.
parent: Parent node in the reconstructed path.
"""
self.coordinate = coordinate
self.g = g
self.h = h
self.f = f
self.parent = parent
def __eq__(self, value: object, /) -> bool:
"""Compare a node to a coordinate.
Args:
value: Object to compare with.
Returns:
``True`` if the value equals the node coordinate, otherwise
``False``.
"""
return value == self.coordinate
def __init__(self, start: tuple[int, int], end: tuple[int, int]) -> None:
"""Initialize the A* solver.
Args:
start: Start coordinates using 1-based indexing.
end: End coordinates using 1-based indexing.
"""
super().__init__(start, end)
def h(self, n: tuple[int, int]) -> int:
"""Compute the Manhattan distance heuristic to the goal.
Args:
n: Coordinates of the current node.
Returns:
The heuristic distance to the end coordinate.
"""
return (
max(n[0], self.end[0])
- min(n[0], self.end[0])
+ max(n[1], self.end[1])
- min(n[1], self.end[1])
)
def get_paths(
self,
maze: NDArray[Any],
actual: tuple[int, int],
close: list["Node"],
) -> list[tuple[int, int]]:
"""Return all reachable neighboring coordinates.
Args:
maze: Maze grid to inspect.
actual: Current coordinate.
close: List of already explored nodes.
Returns:
A list of reachable adjacent coordinates not yet closed.
"""
path = [
(
(actual[0], actual[1] - 1)
if not maze[actual[1]][actual[0]].get_north()
and actual[1] > 0
and (actual[0], actual[1] - 1)
not in [n.coordinate for n in close]
else None
),
(
(actual[0] + 1, actual[1])
if not maze[actual[1]][actual[0]].get_est()
and actual[0] < len(maze[0]) - 1
and (actual[0] + 1, actual[1])
not in [n.coordinate for n in close]
else None
),
(
(actual[0], actual[1] + 1)
if not maze[actual[1]][actual[0]].get_south()
and actual[1] < len(maze) - 1
and (actual[0], actual[1] + 1)
not in [n.coordinate for n in close]
else None
),
(
(actual[0] - 1, actual[1])
if not maze[actual[1]][actual[0]].get_west()
and actual[0] > 0
and (actual[0] - 1, actual[1])
not in [n.coordinate for n in close]
else None
),
]
return [p for p in path if p is not None]
def get_path(self, maze: NDArray[Any]) -> list["Node"]:
"""Perform A* exploration until the destination is reached.
Args:
maze: Maze grid to solve.
Returns:
The closed list ending with the goal node.
Raises:
Exception: If no path can be found.
"""
open: list[AStar.Node] = []
close: list[AStar.Node] = []
open.append(
AStar.Node(
self.start,
0,
self.h(self.start),
self.h(self.start),
None,
)
)
while len(open) > 0:
to_check = sorted(open, key=lambda x: x.f)[0]
open.remove(to_check)
close.append(to_check)
if to_check.coordinate == self.end:
return close
paths = self.get_paths(maze, to_check.coordinate, close)
for path in paths:
open.append(
self.Node(
path,
to_check.g + 1,
self.h(path),
self.h(path) + to_check.g + 1,
to_check,
)
)
raise Exception("Path not found")
def get_rev_dir(self, current: Node) -> str:
"""Determine the direction taken from the parent to the current node.
Args:
current: Current node in the reconstructed path.
Returns:
A cardinal direction letter.
Raises:
Exception: If the parent-child relationship cannot be translated.
"""
if current.parent.coordinate == (
current.coordinate[0],
current.coordinate[1] - 1,
):
return "S"
elif current.parent.coordinate == (
current.coordinate[0] + 1,
current.coordinate[1],
):
return "W"
elif current.parent.coordinate == (
current.coordinate[0],
current.coordinate[1] + 1,
):
return "N"
elif current.parent.coordinate == (
current.coordinate[0] - 1,
current.coordinate[1],
):
return "E"
else:
raise Exception("Translate error: AStar path not found")
def translate(self, close: list["Node"]) -> str:
"""Translate a node chain into a path string.
Args:
close: Closed list ending with the goal node.
Returns:
A string of direction letters from start to end.
"""
current = close[-1]
res = ""
while True:
res = self.get_rev_dir(current) + res
current = current.parent
if current.coordinate == self.start:
break
return res
def solve(
self, maze: Maze, height: int | None = None, width: int | None = None
) -> str:
"""Solve the maze using A*.
Args:
maze: The maze to solve.
height: Unused optional maze height.
width: Unused optional maze width.
Returns:
A string representing the path using cardinal directions.
"""
maze_arr = maze.get_maze()
if maze_arr is None:
raise Exception("Maze is not initialized")
path: list[AStar.Node] = self.get_path(maze_arr)
return self.translate(path)
class DepthFirstSearchSolver(MazeSolver):
"""Solve a maze using depth-first search with backtracking."""
def __init__(self, start: tuple[int, int], end: tuple[int, int]):
"""Initialize the depth-first search solver.
Args:
start: Start coordinates using 1-based indexing.
end: End coordinates using 1-based indexing.
"""
super().__init__(start, end)
def solve(
self, maze: Maze, height: int | None = None, width: int | None = None
) -> str:
"""Solve the maze using depth-first search.
Args:
maze: The maze to solve.
height: Maze height.
width: Maze width.
Returns:
A string representing the path using cardinal directions.
Raises:
Exception: If no path can be found.
"""
path_str = ""
if height is None or width is None:
raise Exception("We need Height and Width in the arg")
visited: NDArray[Any] = np.zeros((height, width), dtype=bool)
path: list[tuple[int, int]] = list()
move: list[str] = list()
maze_s = maze.get_maze()
if maze_s is None:
raise Exception("Maze is not initializef")
coord = self.start
h_w: tuple[int, int] = (height, width)
while coord != self.end:
visited[coord] = True
path.append(coord)
rand_p: list[str] = self.random_path(visited, coord, maze_s, h_w)
if not rand_p:
path, move = self.back_on_step(
path, visited, maze_s, h_w, move
)
if not path:
break
coord = path[-1]
rand_p = self.random_path(visited, coord, maze_s, h_w)
next = self.next_path(rand_p)
move.append(next)
coord = self.next_cell(coord, next)
for m in move:
path_str += m
if not path:
raise Exception("Path not found")
return path_str
@staticmethod
def random_path(
visited: NDArray[Any],
coord: tuple[int, int],
maze: NDArray[Any],
h_w: tuple[int, int],
) -> list[str]:
"""Return all valid unvisited directions from the current cell.
Args:
visited: Boolean array marking visited cells.
coord: Current coordinate.
maze: Maze grid to inspect.
h_w: Tuple containing maze height and width.
Returns:
A list of valid direction letters.
"""
random_p = []
h, w = h_w
y, x = coord
if y - 1 >= 0 and not maze[y][x].get_north() and not visited[y - 1][x]:
random_p.append("N")
if y + 1 < h and not maze[y][x].get_south() and not visited[y + 1][x]:
random_p.append("S")
if x - 1 >= 0 and not maze[y][x].get_west() and not visited[y][x - 1]:
random_p.append("W")
if x + 1 < w and not maze[y][x].get_est() and not visited[y][x + 1]:
random_p.append("E")
return random_p
@staticmethod
def next_path(rand_path: list[str]) -> str:
"""Select the next move at random.
Args:
rand_path: List of available directions.
Returns:
A randomly selected direction.
"""
return random.choice(rand_path)
@staticmethod
def back_on_step(
path: list[tuple[int, int]],
visited: NDArray[Any],
maze: NDArray[Any],
h_w: tuple[int, int],
move: list[str],
) -> tuple[list[Any], list[Any]]:
"""Backtrack until a cell with an unexplored path is found.
Args:
path: Current path of visited coordinates.
visited: Boolean array marking visited cells.
maze: Maze grid to inspect.
h_w: Tuple containing maze height and width.
move: List of moves made so far.
Returns:
A tuple containing the updated path and move list.
"""
while path:
last = path[-1]
if DepthFirstSearchSolver.random_path(visited, last, maze, h_w):
break
path.pop()
move.pop()
return path, move
@staticmethod
def next_cell(coord: tuple[int, int], next: str) -> tuple[int, int]:
"""Return the coordinates of the next cell in the given direction.
Args:
coord: Current coordinate.
next: Direction to move.
Returns:
The coordinates of the next cell.
"""
y, x = coord
next_step = {"N": (-1, 0), "S": (1, 0), "W": (0, -1), "E": (0, 1)}
add_y, add_x = next_step[next]
return (y + add_y, x + add_x)
+18
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@@ -0,0 +1,18 @@
from mazegen.Cell import Cell
from mazegen.Maze import Maze
from mazegen.MazeGenerator import MazeGenerator, DepthFirstSearch
from mazegen.MazeGenerator import Kruskal
from mazegen.MazeSolver import MazeSolver, AStar, DepthFirstSearchSolver
__version__ = "1.0.0"
__author__ = "us"
__all__ = [
"Cell",
"Maze",
"MazeGenerator",
"DepthFirstSearchSolver",
"MazeSolver",
"AStar",
"Kruskal",
"DepthFirstSearch",
]
View File