41 lines
1.3 KiB
Python
41 lines
1.3 KiB
Python
|
from task2.strategyObjects.pathFindingStrategy import PathFindingStrategy
|
|||
|
|
from task2.strategyObjects.util import restorePath
|
|||
|
|
|
|||
|
|
from task2.mazeObjects.maze import Maze
|
|||
|
|
from task2.mazeObjects.cell import Cell
|
|||
|
|
from task2.mazeObjects.path import Path
|
|||
|
|
|
|||
|
|
class DFS(PathFindingStrategy):
|
|||
|
|
"""Поиск в глубину – быстрый, но не обязательно кратчайший.
|
|||
|
|
Возвращает None, если пути нет"""
|
|||
|
|
def findPath(self, maze: Maze, start: Cell, exit: Cell) -> Path:
|
|||
|
|
visited = dict()
|
|||
|
|
parents = dict()
|
|||
|
|
stack = []
|
|||
|
|
|
|||
|
|
stack.append(start)
|
|||
|
|
visited[start] = 0
|
|||
|
|
parents[start] = None
|
|||
|
|
|
|||
|
|
found_exit = False
|
|||
|
|
while stack:
|
|||
|
|
current = stack.pop()
|
|||
|
|
|
|||
|
|
# Условие нахождение выхода
|
|||
|
|
if current.isExit:
|
|||
|
|
found_exit = True
|
|||
|
|
break
|
|||
|
|
|
|||
|
|
# Перебор соседей
|
|||
|
|
for hood in maze.getNeighbors(current):
|
|||
|
|
if hood in visited:
|
|||
|
|
continue
|
|||
|
|
visited[hood] = visited[current] + 1
|
|||
|
|
parents[hood] = current
|
|||
|
|
stack.append(hood)
|
|||
|
|
|
|||
|
|
if not found_exit:
|
|||
|
|
path_list = None
|
|||
|
|
else:
|
|||
|
|
path_list = restorePath(parents, exit)
|
|||
|
|
return Path(path_list, len(visited))
|