2026-rff_mp/rybakovaa/lab2/docs/data/laba2.py

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2026-05-17 19:06:27 +00:00
from abc import ABC, abstractmethod
from collections import deque
import heapq
import time
import csv
import random
import os
BASE = os.path.dirname(os.path.abspath(__file__))
class Cell:
def __init__(self, x, y):
self.x = x
self.y = y
self.isWall = False
self.isStart = False
self.isExit = False
def isPassable(self):
return not self.isWall
def __eq__(self, other):
if other is None:
return False
return self.x == other.x and self.y == other.y
def __hash__(self):
return hash((self.x, self.y))
def __lt__(self, other):
return (self.x, self.y) < (other.x, other.y)
class Maze:
def __init__(self, width, height):
self.width = width
self.height = height
self.grid = [[Cell(x, y) for y in range(height)] for x in range(width)]
self.start = None
self.exit = None
def getCell(self, x, y):
if 0 <= x < self.width and 0 <= y < self.height:
return self.grid[x][y]
return None
def getNeighbors(self, cell):
neighbors = []
for dx, dy in [(0, 1), (0, -1), (1, 0), (-1, 0)]:
n = self.getCell(cell.x + dx, cell.y + dy)
if n and n.isPassable():
neighbors.append(n)
return neighbors
class MazeBuilder(ABC):
@abstractmethod
def buildFromFile(self, filename):
pass
class TextFileMazeBuilder(MazeBuilder):
def buildFromFile(self, filename):
with open(filename, "r", encoding="utf-8") as f:
lines = [line.rstrip("\n\r") for line in f.readlines()]
height = len(lines)
width = len(lines[0]) if height > 0 else 0
for line in lines:
if len(line) != width:
raise ValueError("все строки должны быть одной длины")
maze = Maze(width, height)
for y in range(height):
for x in range(width):
ch = lines[y][x]
cell = maze.getCell(x, y)
if ch == "#":
cell.isWall = True
elif ch == " ":
cell.isWall = False
elif ch == "S":
cell.isWall = False
cell.isStart = True
maze.start = cell
elif ch == "E":
cell.isWall = False
cell.isExit = True
maze.exit = cell
else:
raise ValueError(f"неизвестный символ: {ch}")
if maze.start is None:
raise ValueError("нет старта (S)")
if maze.exit is None:
raise ValueError("нет выхода (E)")
return maze
class PathFindingStrategy(ABC):
@abstractmethod
def findPath(self, maze, start, exit_cell):
pass
def _reconstruct(self, parent, exit_cell):
path = []
curr = exit_cell
while curr is not None:
path.append(curr)
curr = parent.get(curr)
path.reverse()
return path
class BFSStrategy(PathFindingStrategy):
def findPath(self, maze, start, exit_cell):
if exit_cell is None:
return []
queue = deque([start])
visited = {start}
parent = {start: None}
while queue:
curr = queue.popleft()
if curr == exit_cell:
return self._reconstruct(parent, exit_cell)
for n in maze.getNeighbors(curr):
if n not in visited:
visited.add(n)
parent[n] = curr
queue.append(n)
return []
class DFSStrategy(PathFindingStrategy):
def findPath(self, maze, start, exit_cell):
if exit_cell is None:
return []
stack = [start]
visited = {start}
parent = {start: None}
while stack:
curr = stack.pop()
if curr == exit_cell:
return self._reconstruct(parent, exit_cell)
for n in maze.getNeighbors(curr):
if n not in visited:
visited.add(n)
parent[n] = curr
stack.append(n)
return []
class AStarStrategy(PathFindingStrategy):
def _heuristic(self, cell, exit_cell):
return abs(cell.x - exit_cell.x) + abs(cell.y - exit_cell.y)
def findPath(self, maze, start, exit_cell):
if exit_cell is None:
return []
open_set = []
heapq.heappush(open_set, (0, start))
parent = {start: None}
g_score = {start: 0}
while open_set:
curr = heapq.heappop(open_set)[1]
if curr == exit_cell:
return self._reconstruct(parent, exit_cell)
for n in maze.getNeighbors(curr):
new_g = g_score[curr] + 1
if n not in g_score or new_g < g_score[n]:
g_score[n] = new_g
parent[n] = curr
f = new_g + self._heuristic(n, exit_cell)
heapq.heappush(open_set, (f, n))
return []
class SearchStats:
def __init__(self, time_ms, visited, path_len):
self.time_ms = time_ms
self.visited_cells = visited
self.path_length = path_len
class MazeSolver:
def __init__(self, maze):
self.maze = maze
self.strategy = None
self.observers = []
def setStrategy(self, strategy):
self.strategy = strategy
def attach(self, observer):
self.observers.append(observer)
def notify(self, event):
for obs in self.observers:
obs.update(event)
def solve(self):
if self.strategy is None:
raise ValueError("стратегия не выбрана")
start_time = time.perf_counter()
path = self.strategy.findPath(self.maze, self.maze.start, self.maze.exit)
elapsed_ms = (time.perf_counter() - start_time) * 1000
stats = SearchStats(elapsed_ms, len(path), len(path))
self.notify({"type": "path_found", "maze": self.maze, "path": path, "stats": stats})
return path, stats
class Observer(ABC):
@abstractmethod
def update(self, event):
pass
class ConsoleView(Observer):
def update(self, event):
if event["type"] == "path_found":
stats = event["stats"]
print(f"длина пути {stats.path_length}, время {stats.time_ms:.2f} мс")
def save_maze(maze, filename):
path = os.path.join(BASE, filename)
with open(path, "w", encoding="utf-8") as f:
for y in range(maze.height):
line = ""
for x in range(maze.width):
cell = maze.getCell(x, y)
if cell == maze.start:
line += "S"
elif cell == maze.exit:
line += "E"
elif cell.isWall:
line += "#"
else:
line += " "
f.write(line + "\n")
def generate_with_walls(w, h, prob=0.3):
maze = Maze(w, h)
for x in range(w):
for y in range(h):
if random.random() < prob:
maze.getCell(x, y).isWall = True
maze.getCell(0, 0).isWall = False
maze.getCell(w - 1, h - 1).isWall = False
for x in range(w):
maze.getCell(x, 0).isWall = False
for y in range(h):
maze.getCell(w - 1, y).isWall = False
maze.getCell(0, 0).isStart = True
maze.start = maze.getCell(0, 0)
maze.getCell(w - 1, h - 1).isExit = True
maze.exit = maze.getCell(w - 1, h - 1)
return maze
def generate_empty(w, h):
maze = Maze(w, h)
for x in range(w):
for y in range(h):
maze.getCell(x, y).isWall = False
maze.getCell(0, 0).isStart = True
maze.start = maze.getCell(0, 0)
maze.getCell(w - 1, h - 1).isExit = True
maze.exit = maze.getCell(w - 1, h - 1)
return maze
def generate_no_exit(w, h):
maze = generate_with_walls(w, h, 0.3)
exit_cell = maze.getCell(w - 1, h - 1)
exit_cell.isWall = True
exit_cell.isExit = False
maze.exit = None
return maze
def run_experiment(maze, strategy_class, maze_name, repeats=5):
times = []
path_lens = []
for _ in range(repeats):
solver = MazeSolver(maze)
solver.setStrategy(strategy_class())
path, stats = solver.solve()
times.append(stats.time_ms)
path_lens.append(len(path))
raw = strategy_class.__name__
strat_name = "A" if raw == "AStarStrategy" else raw.replace("Strategy", "")
return {
"лабиринт": maze_name,
"стратегия": strat_name,
"время_ср": sum(times) / repeats,
"длина_пути_ср": sum(path_lens) / repeats,
"путь_найден": any(l > 0 for l in path_lens),
}
def main():
mazes = []
small = generate_with_walls(10, 10, 0.2)
save_maze(small, "maze_small.txt")
mazes.append(("маленький 10x10", small))
medium = generate_with_walls(50, 50, 0.3)
save_maze(medium, "maze_medium.txt")
mazes.append(("средний 50x50", medium))
large = generate_with_walls(100, 100, 0.3)
save_maze(large, "maze_large.txt")
mazes.append(("большой 100x100", large))
empty = generate_empty(50, 50)
save_maze(empty, "maze_empty.txt")
mazes.append(("пустой 50x50", empty))
no_exit = generate_no_exit(20, 20)
save_maze(no_exit, "maze_no_exit.txt")
mazes.append(("без выхода 20x20", no_exit))
strategies = [BFSStrategy, DFSStrategy, AStarStrategy]
results = []
for maze_name, maze in mazes:
print(maze_name)
for strat in strategies:
res = run_experiment(maze, strat, maze_name)
results.append(res)
print(f" {strat.__name__}: {res['время_ср']:.2f} мс")
csv_path = os.path.join(BASE, "resultslab.csv")
with open(csv_path, "w", newline="", encoding="utf-8-sig") as f:
writer = csv.DictWriter(
f,
fieldnames=["лабиринт", "стратегия", "время_ср", "длина_пути_ср", "путь_найден"],
delimiter=";",
)
writer.writeheader()
for row in results:
row_ru = row.copy()
row_ru["путь_найден"] = "да" if row["путь_найден"] else "нет"
writer.writerow(row_ru)
try:
import matplotlib.pyplot as plt
plt.rcParams["font.sans-serif"] = ["Segoe UI", "Arial", "Tahoma", "DejaVu Sans"]
plt.rcParams["axes.unicode_minus"] = False
labyrinths = []
for r in results:
if r["лабиринт"] not in labyrinths:
labyrinths.append(r["лабиринт"])
fig, axes = plt.subplots(1, len(labyrinths), figsize=(4 * len(labyrinths), 4))
if len(labyrinths) == 1:
axes = [axes]
for idx, lab in enumerate(labyrinths):
times = []
for s in ["BFS", "DFS", "A"]:
for r in results:
if r["лабиринт"] == lab and r["стратегия"] == s:
times.append(r["время_ср"])
break
axes[idx].bar(["BFS", "DFS", "A"], times, color=["#1a5632", "#0e5fb4", "#e67e22"])
axes[idx].set_title(lab)
axes[idx].set_ylabel("мс")
plt.tight_layout()
plt.savefig(os.path.join(BASE, "maze_time_comparison.png"))
plt.close()
except ImportError:
pass
report_path = os.path.join(os.path.dirname(BASE), "report.md")
with open(report_path, "w", encoding="utf-8-sig") as f:
f.write("# Отчёт: поиск пути в лабиринте\n\n")
f.write("Паттерны: Builder, Strategy, Observer\n\n")
f.write("```mermaid\nclassDiagram\n")
f.write("class MazeBuilder\nclass TextFileMazeBuilder\n")
f.write("class PathFindingStrategy\nclass BFSStrategy\n")
f.write("class DFSStrategy\nclass AStarStrategy\n")
f.write("class MazeSolver\nclass Observer\nclass ConsoleView\n")
f.write("MazeBuilder <|-- TextFileMazeBuilder\n")
f.write("PathFindingStrategy <|-- BFSStrategy\n")
f.write("PathFindingStrategy <|-- DFSStrategy\n")
f.write("PathFindingStrategy <|-- AStarStrategy\n")
f.write("Observer <|-- ConsoleView\n")
f.write("MazeSolver --> PathFindingStrategy\n")
f.write("```\n\n")
f.write("| Лабиринт | Стратегия | Время (мс) | Длина пути | Найден |\n")
f.write("| --- | --- | --- | --- | --- |\n")
for r in results:
found = "да" if r["путь_найден"] else "нет"
f.write(
f"| {r['лабиринт']} | {r['стратегия']} | {r['время_ср']:.2f} | "
f"{r['длина_пути_ср']:.0f} | {found} |\n"
)
f.write("\n![График](data/maze_time_comparison.png)\n\n")
f.write("## Выводы\n\n")
f.write("- BFS и A* находят кратчайший путь.\n")
f.write("- DFS путь может быть длиннее.\n")
f.write("- На пустом лабиринте алгоритмы работают быстрее всего.\n")
f.write("- Без выхода все стратегии возвращают пустой путь.\n")
print("Готово:", report_path)
if __name__ == "__main__":
main()