429 lines
16 KiB
Python
429 lines
16 KiB
Python
import abc
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import heapq
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import time
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from collections import deque
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from dataclasses import dataclass
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from typing import List, Optional, Dict, Set, Tuple, Any
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class Cell:
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#тут что такое клетка
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def __init__(self, x: int, y: int, is_wall: bool = False,
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is_exit: bool = False, is_start: bool = False):
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self.x = x
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self.y = y
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self.is_wall = is_wall
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self.is_exit = is_exit
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self.is_start = is_start
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def is_passable(self) -> bool: #можно ли пройти через клетку
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return not self.is_wall
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def __repr__(self) -> str:
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return f"Cell({self.x},{self.y})"
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class Maze:
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def __init__(self, width: int, height: int): #что содержит лабиринт, начало конец и тд
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self.width = width
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self.height = height
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self.grid: List[List[Cell]] = []
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self.start_cell: Optional[Cell] = None
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self.exit_cell: Optional[Cell] = None
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def set_cell(self, x: int, y: int, cell: Cell) -> None: #ставим клетку куда надо или не ставим если в границы не попала
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if not (0 <= x < self.width and 0 <= y < self.height):
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raise IndexError("координаты вне границ лабиринта")
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self.grid[y][x] = cell
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def get_cell(self, x: int, y: int) -> Optional[Cell]: #тут уже из коррдинат клетку вытаскиваем
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if 0 <= x < self.width and 0 <= y < self.height:
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return self.grid[y][x]
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return None
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def get_neighbors(self, cell: Cell) -> List[Cell]: #если соседняя клетка проходима - добавляем
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neighbors = []
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for dx, dy in [(0, -1), (0, 1), (-1, 0), (1, 0)]:
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nx, ny = cell.x + dx, cell.y + dy
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neighbor = self.get_cell(nx, ny)
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if neighbor and neighbor.is_passable():
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neighbors.append(neighbor)
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return neighbors
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class MazeBuilder(abc.ABC):
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"""Абстрактный строитель лабиринта."""
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@abc.abstractmethod
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def build_from_file(self, filename: str) -> Maze:
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"""Построить лабиринт из файла."""
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pass
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class TextFileMazeBuilder(MazeBuilder):
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"""Строитель лабиринта из текстового файла.
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# - стена, пробел - проход, S - старт, E - выход."""
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def build_from_file(self, filename: str) -> Maze:
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lines = []
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with open(filename, 'r', encoding='utf-8') as f:
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for line in f:
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line = line.rstrip('\n')
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if line: #игнорируем пустые строки
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lines.append(line)
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if not lines:
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raise ValueError("Файл пуст")
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height = len(lines)
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width = max(len(line) for line in lines)
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maze = Maze(width, height)
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# Инициализируем сетку пустыми клетками (по умолчанию стенами)
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maze.grid = [[Cell(x, y, is_wall=True) for x in range(width)] for y in range(height)]
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start_cell = None
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exit_cell = None
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for y, line in enumerate(lines):
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for x, ch in enumerate(line):
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if x >= width:
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continue
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if ch == '#':
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# стена (уже создана по умолчанию)
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continue
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elif ch == ' ':
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# проход
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cell = Cell(x, y, is_wall=False)
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elif ch == 'S':
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cell = Cell(x, y, is_wall=False, is_start=True)
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start_cell = cell
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elif ch == 'E':
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cell = Cell(x, y, is_wall=False, is_exit=True)
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exit_cell = cell
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else:
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# любой другой символ считаем проходом
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cell = Cell(x, y, is_wall=False)
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maze.set_cell(x, y, cell)
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# Проверяем наличие старта и выхода
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if start_cell is None:
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raise ValueError("В лабиринте отсутствует стартовая клетка (S)")
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if exit_cell is None:
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raise ValueError("В лабиринте отсутствует выход (E)")
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maze.start_cell = start_cell
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maze.exit_cell = exit_cell
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return maze
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# ============================== Паттерн Strategy ==============================
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class PathFindingStrategy(abc.ABC):
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"""Интерфейс стратегии поиска пути."""
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@abc.abstractmethod
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def find_path(self, maze: Maze, start: Cell, exit_: Cell) -> Tuple[List[Cell], int]:
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"""
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Возвращает (путь в виде списка клеток от start до exit_, количество посещённых клеток).
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Если пути нет, возвращает ([], visited_count).
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"""
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pass
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class BFSStrategy(PathFindingStrategy):
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"""Поиск в ширину — гарантирует кратчайший путь."""
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def find_path(self, maze: Maze, start: Cell, exit_: Cell) -> Tuple[List[Cell], int]:
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if start is exit_:
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return [start], 1
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queue = deque([start])
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visited: Set[Cell] = {start}
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parent: Dict[Cell, Optional[Cell]] = {start: None}
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while queue:
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current = queue.popleft()
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if current is exit_:
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# восстановление пути
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path = []
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cur = current
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while cur is not None:
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path.append(cur)
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cur = parent[cur]
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path.reverse()
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return path, len(visited)
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for neighbor in maze.get_neighbors(current):
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if neighbor not in visited:
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visited.add(neighbor)
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parent[neighbor] = current
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queue.append(neighbor)
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return [], len(visited)
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class DFSStrategy(PathFindingStrategy):
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"""Поиск в глубину — не гарантирует кратчайший путь, но быстр."""
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def find_path(self, maze: Maze, start: Cell, exit_: Cell) -> Tuple[List[Cell], int]:
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if start is exit_:
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return [start], 1
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stack = [start]
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visited: Set[Cell] = {start}
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parent: Dict[Cell, Optional[Cell]] = {start: None}
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while stack:
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current = stack.pop()
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if current is exit_:
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path = []
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cur = current
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while cur is not None:
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path.append(cur)
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cur = parent[cur]
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path.reverse()
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return path, len(visited)
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for neighbor in maze.get_neighbors(current):
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if neighbor not in visited:
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visited.add(neighbor)
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parent[neighbor] = current
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stack.append(neighbor)
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return [], len(visited)
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class AStarStrategy(PathFindingStrategy):
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"""Алгоритм A* с манхэттенской эвристикой."""
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@staticmethod
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def _heuristic(cell: Cell, target: Cell) -> int:
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"""Манхэттенское расстояние."""
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return abs(cell.x - target.x) + abs(cell.y - target.y)
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def find_path(self, maze: Maze, start: Cell, exit_: Cell) -> Tuple[List[Cell], int]:
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if start is exit_:
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return [start], 1
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# Приоритетная очередь: (f, counter, cell)
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counter = 0
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open_set = [(0, counter, start)]
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g_score: Dict[Cell, int] = {start: 0}
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f_score: Dict[Cell, int] = {start: self._heuristic(start, exit_)}
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parent: Dict[Cell, Optional[Cell]] = {start: None}
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closed_set: Set[Cell] = set()
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visited_count = 0
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while open_set:
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_, _, current = heapq.heappop(open_set)
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if current in closed_set:
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continue
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closed_set.add(current)
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visited_count = len(closed_set) # количество обработанных клеток
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if current is exit_:
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path = []
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cur = current
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while cur is not None:
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path.append(cur)
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cur = parent[cur]
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path.reverse()
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return path, visited_count
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for neighbor in maze.get_neighbors(current):
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if neighbor in closed_set:
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continue
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tentative_g = g_score[current] + 1
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if neighbor not in g_score or tentative_g < g_score[neighbor]:
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parent[neighbor] = current
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g_score[neighbor] = tentative_g
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f = tentative_g + self._heuristic(neighbor, exit_)
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f_score[neighbor] = f
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counter += 1
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heapq.heappush(open_set, (f, counter, neighbor))
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return [], visited_count
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# ============================== Статистика ==============================
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@dataclass
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class SearchStats:
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"""Статистика поиска."""
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time_ms: float # время выполнения в миллисекундах
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visited_cells: int # количество посещённых клеток
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path_length: int # длина найденного пути (0 если пути нет)
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path_found: bool # найден ли путь
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# ============================== Паттерн Observer ==============================
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class Observer(abc.ABC):
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"""Интерфейс наблюдателя."""
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@abc.abstractmethod
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def update(self, event_type: str, data: Any = None) -> None:
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"""Получить уведомление от субъекта."""
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pass
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class Subject:
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"""Субъект, за которым наблюдают."""
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def __init__(self):
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self._observers: List[Observer] = []
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def attach(self, observer: Observer) -> None:
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if observer not in self._observers:
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self._observers.append(observer)
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def detach(self, observer: Observer) -> None:
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if observer in self._observers:
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self._observers.remove(observer)
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def notify(self, event_type: str, data: Any = None) -> None:
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for observer in self._observers:
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observer.update(event_type, data)
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# ============================== MazeSolver (оркестратор) ==============================
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class MazeSolver(Subject):
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"""Решатель лабиринта, использующий стратегию поиска."""
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def __init__(self, maze: Maze, strategy: Optional[PathFindingStrategy] = None):
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super().__init__()
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self.maze = maze
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self._strategy = strategy
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def set_strategy(self, strategy: PathFindingStrategy) -> None:
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"""Сменить алгоритм поиска."""
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self._strategy = strategy
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def solve(self) -> Optional[SearchStats]:
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"""Выполнить поиск пути с текущей стратегией.
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Возвращает статистику или None, если стратегия не установлена."""
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if self._strategy is None:
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print("Стратегия не установлена.")
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return None
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self.notify("solving_start", {"strategy": self._strategy.__class__.__name__})
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start_time = time.perf_counter()
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path, visited = self._strategy.find_path(self.maze, self.maze.start_cell, self.maze.exit_cell)
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end_time = time.perf_counter()
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time_ms = (end_time - start_time) * 1000.0
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path_found = len(path) > 0
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stats = SearchStats(
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time_ms=time_ms,
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visited_cells=visited,
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path_length=len(path) if path_found else 0,
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path_found=path_found
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)
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if path_found:
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self.notify("path_found", {"path": path, "stats": stats})
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else:
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self.notify("no_path", {"stats": stats})
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self.notify("solving_end", {"stats": stats})
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return stats
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class ConsoleView(Observer):
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"""Отображает лабиринт и найденный путь в консоли."""
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def __init__(self, maze: Maze):
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self.maze = maze
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self.last_path: List[Cell] = []
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def update(self, event_type: str, data: Any = None) -> None:
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if event_type == "path_found":
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self.last_path = data["path"]
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self.render()
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elif event_type == "no_path":
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self.last_path = []
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self.render(no_path=True)
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elif event_type == "solving_start":
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print(f"\n== Поиск пути (алгоритм: {data['strategy']}) ==\n")
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def render(self, no_path: bool = False) -> None:
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"""Отрисовать лабиринт с текущим найденным путём."""
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# Создаём множество клеток пути для быстрой проверки
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path_set = set(self.last_path) if self.last_path else set()
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for y in range(self.maze.height):
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row = []
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for x in range(self.maze.width):
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cell = self.maze.get_cell(x, y)
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if cell is None:
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row.append('?')
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continue
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if cell is self.maze.start_cell:
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row.append('S')
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elif cell is self.maze.exit_cell:
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row.append('E')
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elif cell in path_set:
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row.append('*')
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elif cell.is_wall:
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row.append('#')
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else:
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row.append(' ')
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print(''.join(row))
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if no_path:
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print("\nПуть не найден!")
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elif self.last_path:
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print(f"\nНайден путь длиной {len(self.last_path)} клеток.")
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else:
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print("\nОжидание решения...")
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def main():
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import sys
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if len(sys.argv) < 2:
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print("для запуска: python main.py <имя_лабиринта>.txt")
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return
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filename = sys.argv[1]
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# Строим лабиринт из файла (Builder)
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builder = TextFileMazeBuilder()
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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"Ошибка загрузки лабиринта: {e}")
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return
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# Создаём решатель и прикрепляем наблюдателя
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solver = MazeSolver(maze)
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view = ConsoleView(maze)
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solver.attach(view)
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# Меню выбора стратегии
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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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}
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print("\nвыберите алгоритм поиска:")
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print("1. BFS")
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print("2. DFS")
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print("3. A*")
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choice = input("введите (1/2/3): ").strip()
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strategy = strategies.get(choice)
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if not strategy:
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print("неверный выбор, по умолчанию используется BFS.")
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strategy = BFSStrategy()
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solver.set_strategy(strategy)
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stats = solver.solve()
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if stats:
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print("\nстатистика по поиску пути в данном лабиринте")
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print(f"выбранный алгоритм: {strategy.__class__.__name__}")
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print(f"время выполнения: {stats.time_ms:.3f} мс")
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print(f"посещено клеток: {stats.visited_cells}")
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print(f"путь найден?: {'да' if stats.path_found else 'нет'}")
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if stats.path_found:
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print(f"длина пути: {stats.path_length}")
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if __name__ == "__main__":
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main() |