589 lines
17 KiB
Python
589 lines
17 KiB
Python
import time
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import heapq
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from collections import deque
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from typing import List, Optional, Dict, Tuple
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from abc import ABC, abstractmethod
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import csv
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import random
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class Cell:
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def __init__(self, x: int, y: int):
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self.x = x
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self.y = y
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self.is_wall = False
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self.is_start = False
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self.is_exit = False
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def is_passable(self) -> bool:
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return not self.is_wall
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class Maze:
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def __init__(self, width: int, height: int):
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self.width = width
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self.height = height
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self.cells = [[Cell(x, y) for y in range(height)] for x in range(width)]
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self.start: Optional[Cell] = None
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self.exit: Optional[Cell] = None
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def get_cell(self, x: int, y: int) -> Optional[Cell]:
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if 0 <= x < self.width and 0 <= y < self.height:
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return self.cells[x][y]
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return None
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def get_neighbors(self, cell: Cell) -> List[Cell]:
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neighbors = []
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for dx, dy in [(-1, 0), (1, 0), (0, -1), (0, 1)]:
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nx, ny = cell.x + dx, cell.y + dy
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nb = self.get_cell(nx, ny)
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if nb and nb.is_passable():
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neighbors.append(nb)
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return neighbors
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class MazeBuilder(ABC):
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@abstractmethod
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def build_from_file(self, filename: str) -> Maze:
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pass
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class TextFileMazeBuilder(MazeBuilder):
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def build_from_file(self, filename: str) -> Maze:
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with open(filename, 'r', encoding='utf-8') as f:
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lines = [line.rstrip('\n') for line in f.readlines()]
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height = len(lines)
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width = max(len(line) for line in lines) if height > 0 else 0
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maze = Maze(width, height)
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for y, line in enumerate(lines):
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for x, ch in enumerate(line):
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cell = maze.get_cell(x, y)
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if cell is None:
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continue
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if ch == '#':
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cell.is_wall = True
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elif ch == 'S':
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cell.is_start = True
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maze.start = cell
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elif ch == 'E':
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cell.is_exit = True
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maze.exit = cell
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elif ch == ' ':
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pass
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else:
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raise ValueError(f"Unknown character '{ch}' at ({x},{y})")
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if maze.start is None or maze.exit is None:
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raise ValueError("Maze must have start (S) and exit (E)")
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return maze
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class PathFindingStrategy(ABC):
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@abstractmethod
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def find_path(self, maze: Maze, start: Cell, exit: Cell) -> List[Cell]:
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pass
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@abstractmethod
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def get_name(self) -> str:
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pass
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class BFSStrategy(PathFindingStrategy):
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def find_path(self, maze: Maze, start: Cell, exit: Cell) -> List[Cell]:
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queue = deque([start])
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came_from = {start: None}
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while queue:
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current = queue.popleft()
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if current == exit:
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break
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for nb in maze.get_neighbors(current):
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if nb not in came_from:
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came_from[nb] = current
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queue.append(nb)
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if exit not in came_from:
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return []
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path = []
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cur = exit
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while cur:
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path.append(cur)
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cur = came_from[cur]
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path.reverse()
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return path
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def get_name(self) -> str:
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return "BFS"
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class DFSStrategy(PathFindingStrategy):
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def find_path(self, maze: Maze, start: Cell, exit: Cell) -> List[Cell]:
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stack = [start]
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came_from = {start: None}
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while stack:
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current = stack.pop()
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if current == exit:
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break
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for nb in maze.get_neighbors(current):
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if nb not in came_from:
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came_from[nb] = current
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stack.append(nb)
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if exit not in came_from:
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return []
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path = []
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cur = exit
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while cur:
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path.append(cur)
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cur = came_from[cur]
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path.reverse()
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return path
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def get_name(self) -> str:
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return "DFS"
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class AStarStrategy(PathFindingStrategy):
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def _heuristic(self, a: Cell, b: Cell) -> int:
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return abs(a.x - b.x) + abs(a.y - b.y)
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def find_path(self, maze: Maze, start: Cell, exit: Cell) -> List[Cell]:
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open_set = []
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heapq.heappush(open_set, (0, id(start), start))
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came_from = {}
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g_score = {start: 0}
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f_score = {start: self._heuristic(start, exit)}
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while open_set:
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_, _, current = heapq.heappop(open_set)
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if current == exit:
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path = []
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cur = exit
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while cur in came_from:
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path.append(cur)
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cur = came_from[cur]
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path.append(start)
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path.reverse()
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return path
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for neighbor in maze.get_neighbors(current):
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tentative_g = g_score[current] + 1
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if tentative_g < g_score.get(neighbor, float('inf')):
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came_from[neighbor] = current
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g_score[neighbor] = tentative_g
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f_score[neighbor] = tentative_g + self._heuristic(neighbor, exit)
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heapq.heappush(open_set, (f_score[neighbor], id(neighbor), neighbor))
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return []
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def get_name(self) -> str:
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return "A*"
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class DijkstraStrategy(PathFindingStrategy):
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def find_path(self, maze: Maze, start: Cell, exit: Cell) -> List[Cell]:
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pq = [(0, id(start), start)]
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distances = {start: 0}
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came_from = {start: None}
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while pq:
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dist, _, current = heapq.heappop(pq)
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if current == exit:
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break
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if dist > distances[current]:
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continue
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for neighbor in maze.get_neighbors(current):
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new_dist = dist + 1
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if new_dist < distances.get(neighbor, float('inf')):
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distances[neighbor] = new_dist
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came_from[neighbor] = current
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heapq.heappush(pq, (new_dist, id(neighbor), neighbor))
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if exit not in came_from:
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return []
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path = []
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cur = exit
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while cur:
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path.append(cur)
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cur = came_from[cur]
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path.reverse()
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return path
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def get_name(self) -> str:
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return "Dijkstra"
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class SearchStats:
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def __init__(self, time_ms: float, visited_cells: int, path_length: int):
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self.time_ms = time_ms
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self.visited_cells = visited_cells
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self.path_length = path_length
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def __str__(self):
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return f"Time: {self.time_ms:.2f}ms, Visited: {self.visited_cells}, Path: {self.path_length}"
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class MazeSolver:
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def __init__(self, maze: Maze, strategy: PathFindingStrategy):
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self.maze = maze
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self.strategy = strategy
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def set_strategy(self, strategy: PathFindingStrategy):
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self.strategy = strategy
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def solve(self) -> Tuple[List[Cell], SearchStats]:
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visited_before = set()
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for x in range(self.maze.width):
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for y in range(self.maze.height):
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cell = self.maze.get_cell(x, y)
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if cell and cell.is_passable():
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visited_before.add(cell)
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start_time = time.perf_counter()
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path = self.strategy.find_path(self.maze, self.maze.start, self.maze.exit)
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end_time = time.perf_counter()
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visited_after = set()
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for x in range(self.maze.width):
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for y in range(self.maze.height):
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cell = self.maze.get_cell(x, y)
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if cell and cell.is_passable():
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visited_after.add(cell)
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visited_cells = len(visited_after)
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stats = SearchStats(
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time_ms=(end_time - start_time) * 1000,
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visited_cells=visited_cells,
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path_length=len(path) if path else 0
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)
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return path, stats
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class Player:
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def __init__(self, start_cell: Cell):
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self.current_cell = start_cell
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self.previous_cell = None
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def move_to(self, cell: Cell) -> bool:
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if cell.is_passable():
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self.previous_cell = self.current_cell
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self.current_cell = cell
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return True
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return False
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def undo(self):
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if self.previous_cell:
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self.current_cell, self.previous_cell = self.previous_cell, None
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return True
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return False
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class Command(ABC):
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@abstractmethod
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def execute(self) -> bool:
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pass
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@abstractmethod
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def undo(self):
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pass
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class MoveCommand(Command):
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def __init__(self, player: Player, maze: Maze, direction: str):
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self.player = player
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self.maze = maze
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self.direction = direction
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self.executed = False
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def execute(self) -> bool:
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dx, dy = 0, 0
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if self.direction == 'W' or self.direction == 'w':
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dy = -1
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elif self.direction == 'S' or self.direction == 's':
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dy = 1
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elif self.direction == 'A' or self.direction == 'a':
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dx = -1
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elif self.direction == 'D' or self.direction == 'd':
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dx = 1
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new_x = self.player.current_cell.x + dx
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new_y = self.player.current_cell.y + dy
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new_cell = self.maze.get_cell(new_x, new_y)
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if new_cell and new_cell.is_passable():
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self.executed = self.player.move_to(new_cell)
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return self.executed
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return False
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def undo(self):
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if self.executed:
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self.player.undo()
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self.executed = False
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class ConsoleView:
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@staticmethod
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def render(maze: Maze, player: Optional[Player] = None, path: Optional[List[Cell]] = None):
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path_set = set()
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if path:
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path_set = set(path)
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for y in range(maze.height):
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line = ""
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for x in range(maze.width):
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cell = maze.get_cell(x, y)
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if not cell:
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line += " "
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elif player and player.current_cell == cell:
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line += "P"
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elif cell.is_start:
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line += "S"
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elif cell.is_exit:
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line += "E"
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elif cell.is_wall:
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line += "#"
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elif path and cell in path_set:
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line += "."
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else:
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line += " "
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print(line)
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print()
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@staticmethod
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def show_stats(stats: SearchStats, algo_name: str):
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print(f"=== {algo_name} Results ===")
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print(stats)
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print()
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def generate_test_maze(width: int, height: int, complexity: float = 0.3) -> Maze:
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maze = Maze(width, height)
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for x in range(width):
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for y in range(height):
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if random.random() < complexity:
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maze.cells[x][y].is_wall = True
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maze.start = maze.get_cell(0, 0)
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if maze.start:
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maze.start.is_start = True
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maze.start.is_wall = False
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maze.exit = maze.get_cell(width - 1, height - 1)
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if maze.exit:
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maze.exit.is_exit = True
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maze.exit.is_wall = False
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return maze
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def generate_empty_maze(width: int, height: int) -> Maze:
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maze = Maze(width, height)
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for x in range(width):
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for y in range(height):
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maze.cells[x][y].is_wall = False
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maze.start = maze.get_cell(0, 0)
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if maze.start:
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maze.start.is_start = True
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maze.exit = maze.get_cell(width - 1, height - 1)
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if maze.exit:
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maze.exit.is_exit = True
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return maze
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def generate_no_exit_maze(width: int, height: int) -> Maze:
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maze = Maze(width, height)
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for x in range(width):
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for y in range(height):
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maze.cells[x][y].is_wall = False
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for x in range(width):
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maze.cells[x][height // 2].is_wall = True
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maze.start = maze.get_cell(0, 0)
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if maze.start:
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maze.start.is_start = True
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maze.exit = maze.get_cell(width - 1, height - 1)
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if maze.exit:
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maze.exit.is_exit = True
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return maze
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def run_experiments():
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mazes_configs = [
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("Small (10x10)", generate_test_maze(10, 10, 0.2)),
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("Medium (50x50)", generate_test_maze(50, 50, 0.25)),
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("Large (100x100)", generate_test_maze(100, 100, 0.3)),
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("Empty (30x30)", generate_empty_maze(30, 30)),
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("No Exit (20x20)", generate_no_exit_maze(20, 20))
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]
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strategies = [BFSStrategy(), DFSStrategy(), AStarStrategy(), DijkstraStrategy()]
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results = []
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for maze_name, maze in mazes_configs:
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print(f"\n=== Testing: {maze_name} ===")
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for strategy in strategies:
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times = []
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visited = []
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path_lengths = []
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solver = MazeSolver(maze, strategy)
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for run in range(5):
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maze_copy = Maze(maze.width, maze.height)
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for x in range(maze.width):
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for y in range(maze.height):
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orig = maze.get_cell(x, y)
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copy = maze_copy.get_cell(x, y)
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if orig:
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copy.is_wall = orig.is_wall
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copy.is_start = orig.is_start
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copy.is_exit = orig.is_exit
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maze_copy.start = maze_copy.get_cell(maze.start.x, maze.start.y) if maze.start else None
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maze_copy.exit = maze_copy.get_cell(maze.exit.x, maze.exit.y) if maze.exit else None
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solver.maze = maze_copy
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solver.set_strategy(strategy)
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path, stats = solver.solve()
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times.append(stats.time_ms)
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visited.append(stats.visited_cells)
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path_lengths.append(stats.path_length)
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avg_time = sum(times) / len(times)
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avg_visited = sum(visited) / len(visited)
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avg_path = sum(path_lengths) / len(path_lengths)
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results.append({
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'maze': maze_name,
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'algorithm': strategy.get_name(),
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'avg_time_ms': avg_time,
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'avg_visited_cells': avg_visited,
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'avg_path_length': avg_path
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})
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print(f"{strategy.get_name()}: {avg_time:.2f}ms, {avg_visited:.0f} cells, path={avg_path:.0f}")
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with open('experiment_results.csv', 'w', newline='', encoding='utf-8') as f:
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writer = csv.DictWriter(f, fieldnames=['maze', 'algorithm', 'avg_time_ms', 'avg_visited_cells', 'avg_path_length'])
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writer.writeheader()
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writer.writerows(results)
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print("\nResults saved to experiment_results.csv")
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def interactive_mode():
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builder = TextFileMazeBuilder()
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print("Interactive Maze Explorer")
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print("1. Load maze from file")
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print("2. Generate random maze")
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choice = input("Choose (1/2): ")
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if choice == '1':
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filename = input("Enter filename: ")
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try:
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maze = builder.build_from_file(filename)
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except Exception as e:
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print(f"Error loading maze: {e}")
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return
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else:
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w = int(input("Width: "))
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h = int(input("Height: "))
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maze = generate_test_maze(w, h, 0.3)
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player = Player(maze.start)
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strategies = {
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'1': BFSStrategy(),
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'2': DFSStrategy(),
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'3': AStarStrategy(),
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'4': DijkstraStrategy()
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}
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print("\nSelect algorithm for solving:")
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print("1. BFS (shortest path)")
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print("2. DFS (fast, not optimal)")
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print("3. A* (heuristic)")
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print("4. Dijkstra")
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algo_choice = input("Choose: ")
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solver = MazeSolver(maze, strategies.get(algo_choice, BFSStrategy()))
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path, stats = solver.solve()
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view = ConsoleView()
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if path:
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print(f"\nPath found! Length: {len(path)}")
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view.show_stats(stats, solver.strategy.get_name())
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else:
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print("\nNo path found!")
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while True:
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view.render(maze, player, path if path else None)
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if player.current_cell == maze.exit:
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print("Congratulations! You reached the exit!")
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break
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cmd = input("Move (W/A/S/D) | U=undo | Q=quit | S=solve: ").upper()
|
|
|
|
if cmd == 'Q':
|
|
break
|
|
elif cmd == 'U':
|
|
player.undo()
|
|
print("Undo last move")
|
|
elif cmd == 'S' and path:
|
|
for cell in path:
|
|
if cell == player.current_cell:
|
|
continue
|
|
player.move_to(cell)
|
|
view.render(maze, player, path)
|
|
input("Press Enter to continue...")
|
|
if player.current_cell == maze.exit:
|
|
print("You reached the exit!")
|
|
break
|
|
elif cmd in ['W', 'A', 'S', 'D']:
|
|
move_cmd = MoveCommand(player, maze, cmd)
|
|
if move_cmd.execute():
|
|
print("Moved")
|
|
else:
|
|
print("Can't move there!")
|
|
|
|
|
|
def main():
|
|
print("Maze Solver with Design Patterns")
|
|
print("1. Run experiments")
|
|
print("2. Interactive mode")
|
|
choice = input("Choose (1/2): ")
|
|
|
|
if choice == '1':
|
|
run_experiments()
|
|
else:
|
|
interactive_mode()
|
|
|
|
|
|
if __name__ == "__main__":
|
|
main() |