345 lines
9.8 KiB
Python
345 lines
9.8 KiB
Python
import sys
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from collections import deque
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import heapq
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import time
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import os
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import csv
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import matplotlib.pyplot as plt
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import numpy as np
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# ----------------------------- Модель клетки -----------------------------
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class GridCell:
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def __init__(self, x, y):
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self._x = x
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self._y = y
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self._blocked = False
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self._entry = False
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self._exit_flag = False
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@property
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def x(self):
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return self._x
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@property
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def y(self):
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return self._y
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@property
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def is_wall(self):
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return self._blocked
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@is_wall.setter
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def is_wall(self, value):
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self._blocked = value
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@property
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def is_start(self):
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return self._entry
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@is_start.setter
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def is_start(self, value):
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self._entry = value
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@property
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def is_exit(self):
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return self._exit_flag
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@is_exit.setter
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def is_exit(self, value):
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self._exit_flag = value
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def passable(self):
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return not self._blocked
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# ----------------------------- Модель лабиринта -----------------------------
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class Labyrinth:
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def __init__(self, width, height):
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self._width = width
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self._height = height
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self._cells = [[GridCell(x, y) for x in range(width)] for y in range(height)]
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self._start_cell = None
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self._exit_cell = None
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@property
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def width(self):
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return self._width
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@property
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def height(self):
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return self._height
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@property
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def start(self):
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return self._start_cell
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@property
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def exit(self):
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return self._exit_cell
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def cell_at(self, x, y):
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if 0 <= x < self._width and 0 <= y < self._height:
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return self._cells[y][x]
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return None
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def configure_cell(self, x, y, cell_type):
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cell = self.cell_at(x, y)
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if cell is None:
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return
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if cell_type == 'wall':
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cell.is_wall = True
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elif cell_type == 'start':
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if self._start_cell:
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self._start_cell.is_start = False
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cell.is_start = True
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cell.is_wall = False
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self._start_cell = cell
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elif cell_type == 'exit':
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if self._exit_cell:
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self._exit_cell.is_exit = False
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cell.is_exit = True
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cell.is_wall = False
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self._exit_cell = cell
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elif cell_type == 'path':
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cell.is_wall = False
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def adjacent_cells(self, cell):
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neighbours = []
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directions = [(0, -1), (0, 1), (-1, 0), (1, 0)]
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for dx, dy in directions:
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nx, ny = cell.x + dx, cell.y + dy
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neighbour = self.cell_at(nx, ny)
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if neighbour and neighbour.passable():
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neighbours.append(neighbour)
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return neighbours
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# ----------------------------- Загрузка лабиринта -----------------------------
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class LabyrinthBuilder:
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def build_from_file(self, filename):
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raise NotImplementedError
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class TxtLabyrinthBuilder(LabyrinthBuilder):
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def build_from_file(self, filename):
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with open(filename, 'r') 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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start_cnt = 0
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exit_cnt = 0
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lab = Labyrinth(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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if ch == "#":
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lab.configure_cell(x, y, "wall")
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elif ch == "S":
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lab.configure_cell(x, y, "start")
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start_cnt += 1
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elif ch == "E":
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lab.configure_cell(x, y, "exit")
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exit_cnt += 1
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else:
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lab.configure_cell(x, y, 'path')
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if start_cnt != 1 or exit_cnt != 1:
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raise ValueError(f"Maze must have exactly one S and one E. Found S={start_cnt}, E={exit_cnt}")
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return lab
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# ----------------------------- Алгоритмы поиска -----------------------------
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class SearchAlgorithm:
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def compute_path(self, maze, start, goal):
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raise NotImplementedError
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def _build_path(self, came_from, start, goal):
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path = []
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cur = goal
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while cur is not None:
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path.append(cur)
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cur = came_from.get(cur)
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path.reverse()
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return path
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def visited_nodes(self):
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return getattr(self, '_visited', 0)
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class BFS(SearchAlgorithm):
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def compute_path(self, maze, start, goal):
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q = deque()
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q.append(start)
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came_from = {start: None}
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visited = {start}
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while q:
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cur = q.popleft()
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if cur == goal:
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self._visited = len(visited)
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return self._build_path(came_from, start, goal)
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for nb in maze.adjacent_cells(cur):
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if nb not in visited:
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visited.add(nb)
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came_from[nb] = cur
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q.append(nb)
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self._visited = len(visited)
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return []
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class DFS(SearchAlgorithm):
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def compute_path(self, maze, start, goal):
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stack = [start]
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came_from = {start: None}
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visited = {start}
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while stack:
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cur = stack.pop()
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if cur == goal:
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self._visited = len(visited)
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return self._build_path(came_from, start, goal)
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for nb in maze.adjacent_cells(cur):
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if nb not in visited:
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visited.add(nb)
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came_from[nb] = cur
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stack.append(nb)
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self._visited = len(visited)
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return []
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class AStar(SearchAlgorithm):
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def _heuristic(self, cell, goal):
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return abs(cell.x - goal.x) + abs(cell.y - goal.y)
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def compute_path(self, maze, start, goal):
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heap = []
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counter = 0
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start_f = self._heuristic(start, goal)
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heapq.heappush(heap, (start_f, counter, start))
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counter += 1
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came_from = {}
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g_score = {start: 0}
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f_score = {start: start_f}
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visited = set()
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while heap:
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cur_f, _, cur = heapq.heappop(heap)
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visited.add(cur)
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if cur == goal:
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self._visited = len(visited)
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return self._build_path(came_from, start, goal)
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if cur_f > f_score.get(cur, float('inf')):
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continue
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for nb in maze.adjacent_cells(cur):
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tentative_g = g_score[cur] + 1
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if tentative_g < g_score.get(nb, float('inf')):
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came_from[nb] = cur
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g_score[nb] = tentative_g
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new_f = tentative_g + self._heuristic(nb, goal)
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f_score[nb] = new_f
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heapq.heappush(heap, (new_f, counter, nb))
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counter += 1
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self._visited = len(visited)
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return []
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# ----------------------------- Оркестратор -----------------------------
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class Pathfinder:
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def __init__(self, maze):
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self._maze = maze
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self._algorithm = None
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self._listeners = []
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def attach(self, listener):
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self._listeners.append(listener)
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def notify(self, event, data):
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for lst in self._listeners:
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lst.update(event, data)
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def set_algorithm(self, algorithm):
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self._algorithm = algorithm
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def solve(self):
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if self._algorithm is None:
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return None
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t0 = time.perf_counter()
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path = self._algorithm.compute_path(self._maze, self._maze.start, self._maze.exit)
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t1 = time.perf_counter()
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elapsed_ms = (t1 - t0) * 1000
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self.notify("path_found", path)
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return PerformanceData(elapsed_ms, self._algorithm.visited_nodes(), len(path))
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class PerformanceData:
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def __init__(self, time_ms, visited, length):
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self.time_ms = time_ms
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self.visited_cells = visited
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self.path_length = length
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# ----------------------------- Наблюдатель и отображение -----------------------------
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class EventListener:
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def update(self, event_type, data):
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raise NotImplementedError
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class ConsoleDisplay(EventListener):
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def __init__(self):
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self._last_path = None
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def update(self, event_type, data):
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if event_type == "maze_loaded":
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self._render_maze(data)
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elif event_type == "path_found":
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self._last_path = data
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self._render_path(data)
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def _render_maze(self, maze):
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os.system('cls' if os.name == 'nt' else 'clear')
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print("=" * (maze.width * 2 + 4))
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print(" LABYRINTH")
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print("=" * (maze.width * 2 + 4))
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for y in range(maze.height):
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print(" ", end='')
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for x in range(maze.width):
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cell = maze.cell_at(x, y)
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if cell == maze.start:
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print('S', end=' ')
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elif cell == maze.exit:
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print('E', end=' ')
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elif cell.is_wall:
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print('#', end=' ')
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else:
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print('.', end=' ')
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print()
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print("=" * (maze.width * 2 + 4))
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print(" S - start E - exit # - wall . - path")
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def _render_path(self, path):
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if not path:
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print("\n Path not found!")
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return
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print(f"\n Path found! Length: {len(path)}")
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if __name__ == "__main__":
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builder = TxtLabyrinthBuilder()
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maze = builder.build_from_file("maze/level1.txt")
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view = ConsoleDisplay()
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view.update("maze_loaded", maze)
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pf = Pathfinder(maze)
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pf.attach(view)
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for algo, name in [(BFS(), "BFS"), (DFS(), "DFS"), (AStar(), "A*")]:
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pf.set_algorithm(algo)
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stats = pf.solve()
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print(f"{name}: {stats.time_ms:.3f}ms, visited={stats.visited_cells}, length={stats.path_length}") |