Реализация алгоритма A*

stepushovgs/labyrinth/mazes/tests/test_lab3.txt

@@ -0,0 +1,9 @@
+####################
+#S                 #
+#  ##########      #
+#  ####            #
+#         ######## #
+#                  #
+#   #######  ####  #
+#                E #
+####################

stepushovgs/labyrinth/source/strategy/astar.py

@@ -1,4 +1,7 @@
-from source.strategy import PathFindingStrategy
+from heapq import *
+
+
+from source.strategy import PathFindingStrategy, reconstruct_path
 from source.classes import Maze, Cell
 
 
@@ -7,8 +10,55 @@ class AStar(PathFindingStrategy):
     def name(self) -> str:
         return "A*"
     
-    def findPath(self, maze: Maze, start: Cell, exit: Cell):
+    def heuristic(self, a: Cell, b: Cell) -> int:
-        pass
+        x1, y1 = a.getXY()
+        x2, y2 = b.getXY()
 
-    def __A__(self, maze: Maze, start: Cell, exit: Cell): 
+        return abs(x1 - x2) + abs(y1 - y2)
-        pass
+    
+    def findPath(self, maze: Maze):
+        start_cell = maze.start
+        exit_cell = maze.exit
+
+        queue = []
+        counter = 0 # счётчик для уникальности, чтобы не сравнивать клетки
+        
+        start_h = self.heuristic(start_cell, exit_cell)
+
+        heappush(queue, (start_h, counter, start_cell))
+        counter += 1
+
+        cost_visited = {start_cell.getXY(): 0}
+        came_from = {start_cell.getXY(): None}
+        visited_count = 1
+
+        while queue:
+            current_cost, _, current_cell = heappop(queue)
+            current_g = cost_visited[current_cell.getXY()]
+
+            if current_cell.getXY() == exit_cell.getXY():
+                return reconstruct_path(
+                    came_from=came_from, 
+                    start=start_cell, 
+                    end=current_cell
+                        ), visited_count
+
+            next_cells = maze.getNeighbors(current_cell)
+
+            for next_cell in next_cells:
+                neighbor_cost = next_cell.value
+                neighbor_cell_xy = next_cell.getXY()
+
+                new_cost = current_g + neighbor_cost
+
+                if neighbor_cell_xy not in cost_visited or new_cost < cost_visited[neighbor_cell_xy]:
+                    priority = new_cost + self.heuristic(next_cell, exit_cell)
+
+                    heappush(queue, (priority, counter, next_cell))
+                    counter += 1
+                    
+                    cost_visited[neighbor_cell_xy] = new_cost
+                    came_from[neighbor_cell_xy] = current_cell
+                    visited_count += 1
+        
+        return [], visited_count

stepushovgs/labyrinth/test.ipynb

@@ -2,14 +2,14 @@
  "cells": [
   {
    "cell_type": "code",
-   "execution_count": 1,
+   "execution_count": 15,
    "id": "4dbe48b6",
    "metadata": {},
    "outputs": [],
    "source": [
     "from source.builder import TextFileMazeBuilder\n",
     "from source.observer import ConsoleView, Event\n",
-    "from source.strategy import MazeSolver, BFS, DFS, Dijkstra\n",
+    "from source.strategy import MazeSolver, BFS, DFS, Dijkstra, AStar\n",
     "# from source.strategy.maze_solver import \n",
     "from source.classes import Cell\n",
     "# from source.strategy import "
@@ -17,19 +17,20 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 2,
+   "execution_count": null,
    "id": "007bf97a",
    "metadata": {},
    "outputs": [],
    "source": [
     "test_lab = './mazes/tests/test_lab.txt'\n",
     "test_lab2 = './mazes/tests/test_lab2.txt'\n",
-    "test_lab3 = './mazes/tests/test_lab20x20.txt'"
+    "test_lab3 = './mazes/tests/test_lab3.txt'\n",
+    "test_lab4 = './mazes/tests/test_lab20x20.txt'"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 3,
+   "execution_count": 17,
    "id": "4489fc7e",
    "metadata": {},
    "outputs": [
@@ -55,7 +56,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 4,
+   "execution_count": 18,
    "id": "fde1eddb",
    "metadata": {},
    "outputs": [
@@ -83,7 +84,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 5,
+   "execution_count": 19,
    "id": "22325f68",
    "metadata": {},
    "outputs": [
@@ -116,7 +117,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 6,
+   "execution_count": 20,
    "id": "19840429",
    "metadata": {},
    "outputs": [
@@ -154,7 +155,7 @@
        "  (7, 1)])"
       ]
      },
-     "execution_count": 6,
+     "execution_count": 20,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -168,7 +169,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 7,
+   "execution_count": 21,
    "id": "73ba37a8",
    "metadata": {},
    "outputs": [
@@ -206,7 +207,7 @@
        "  (7, 1)])"
       ]
      },
-     "execution_count": 7,
+     "execution_count": 21,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -220,7 +221,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 8,
+   "execution_count": 22,
    "id": "857c5c04",
    "metadata": {},
    "outputs": [
@@ -229,11 +230,11 @@
      "output_type": "stream",
      "text": [
       "0\n",
-      "2\n",
       "1\n",
-      "4\n",
       "3\n",
-      "3\n"
+      "4\n",
+      "2\n",
+      "2\n"
      ]
     },
     {
@@ -242,7 +243,7 @@
        "{'0', '1', '2', '3', '4'}"
       ]
      },
-     "execution_count": 8,
+     "execution_count": 22,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -271,7 +272,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 9,
+   "execution_count": 23,
    "id": "9a5ea5cb",
    "metadata": {},
    "outputs": [
@@ -357,7 +358,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 10,
+   "execution_count": 24,
    "id": "32edf4d1",
    "metadata": {},
    "outputs": [
@@ -382,7 +383,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 11,
+   "execution_count": 25,
    "id": "48d20564",
    "metadata": {},
    "outputs": [
@@ -403,7 +404,7 @@
       "#.                                  #\n",
       "#..................................E#\n",
       "#####################################\n",
-      "time: 0.000567700000374316 ms\n",
+      "time: 0.0008461000002171204 ms\n",
       "visited cells: 315\n",
       "path length: 43\n"
      ]
@@ -420,7 +421,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 12,
+   "execution_count": 26,
    "id": "bf13d5ba",
    "metadata": {},
    "outputs": [
@@ -430,25 +431,34 @@
      "text": [
       "DFS\n",
       "Путь найден:\n",
-      "#####################################\n",
+      "####################\n",
-      "#S..................................#\n",
+      "S...#     #     #  #\n",
-      "#                                  .#\n",
+      "###.# ### # ### # ##\n",
-      "#...................................#\n",
+      "#...# # # # # # # ##\n",
-      "#.                                  #\n",
+      "#.### # ### # ### ##\n",
-      "#...................................#\n",
+      "#.#  .....# #   # ##\n",
-      "#                                  .#\n",
+      "#.###.###.### # # ##\n",
-      "#...................................#\n",
+      "#.# #.# #...# # # ##\n",
-      "#.                                  #\n",
+      "#.# #.# ###.# # # ##\n",
-      "#..................................E#\n",
+      "#.# #.#   #.# # # ##\n",
-      "#####################################\n",
+      "#.# #.### #.# # # ##\n",
-      "time: 0.0004403000002639601 ms\n",
+      "#.# #...# #...# # ##\n",
-      "visited cells: 315\n",
+      "#.# ###.# ###.# # ##\n",
-      "path length: 179\n"
+      "#.#   #.#   #.#   ##\n",
+      "#.### #.### #.### ##\n",
+      "#.#...#.# # #.# # ##\n",
+      "#.#.#.#.# # #.# # ##\n",
+      "#.#.#.#.# # #.# # ##\n",
+      "#...#...#   #.....E#\n",
+      "####################\n",
+      "time: 0.00014700000019729487 ms\n",
+      "visited cells: 83\n",
+      "path length: 76\n"
      ]
     }
    ],
    "source": [
-    "maze2 = builder.buildFromFile(test_lab2)\n",
+    "maze2 = builder.buildFromFile(test_lab3)\n",
     "\n",
     "solver = MazeSolver(maze2, DFS(), ConsoleView())\n",
     "print(solver.strategyName())\n",
@@ -458,7 +468,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 13,
+   "execution_count": 27,
    "id": "9383cb75",
    "metadata": {},
    "outputs": [
@@ -468,25 +478,34 @@
      "text": [
       "Dijkstra\n",
       "Путь найден:\n",
-      "#####################################\n",
+      "####################\n",
-      "#S                                  #\n",
+      "S...#     #     #  #\n",
-      "#.                                  #\n",
+      "###.# ### # ### # ##\n",
-      "#.                                  #\n",
+      "#...# # # # # # # ##\n",
-      "#.                                  #\n",
+      "#.### # ### # ### ##\n",
-      "#.                                  #\n",
+      "#.#  .....# #   # ##\n",
-      "#.                                  #\n",
+      "#.###.###.### # # ##\n",
-      "#.                                  #\n",
+      "#.# #.# #...# # # ##\n",
-      "#.                                  #\n",
+      "#.# #.# ###.# # # ##\n",
-      "#..................................E#\n",
+      "#.# #.#   #.# # # ##\n",
-      "#####################################\n",
+      "#.# #.### #.# # # ##\n",
-      "time: 0.0007290000003195019 ms\n",
+      "#.# #...# #...# # ##\n",
-      "visited cells: 315\n",
+      "#.# ###.# ###.# # ##\n",
-      "path length: 43\n"
+      "#.#   #.#   #.#   ##\n",
+      "#.### #.### #.### ##\n",
+      "#.#...#.# # #.# # ##\n",
+      "#.#.#.#.# # #.# # ##\n",
+      "#.#.#.#.# # #.# # ##\n",
+      "#...#...#   #.....E#\n",
+      "####################\n",
+      "time: 0.00022080000007917988 ms\n",
+      "visited cells: 120\n",
+      "path length: 76\n"
      ]
     }
    ],
    "source": [
-    "maze2 = builder.buildFromFile(test_lab2)\n",
+    "maze2 = builder.buildFromFile(test_lab3)\n",
     "\n",
     "solver = MazeSolver(maze2, Dijkstra(), ConsoleView())\n",
     "print(solver.strategyName())\n",
@@ -496,9 +515,56 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 28,
    "id": "835cff61",
    "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "A*\n",
+      "Путь найден:\n",
+      "####################\n",
+      "S...#     #     #  #\n",
+      "###.# ### # ### # ##\n",
+      "#...# # # # # # # ##\n",
+      "#.### # ### # ### ##\n",
+      "#.#  .....# #   # ##\n",
+      "#.###.###.### # # ##\n",
+      "#.# #.# #...# # # ##\n",
+      "#.# #.# ###.# # # ##\n",
+      "#.# #.#   #.# # # ##\n",
+      "#.# #.### #.# # # ##\n",
+      "#.# #...# #...# # ##\n",
+      "#.# ###.# ###.# # ##\n",
+      "#.#   #.#   #.#   ##\n",
+      "#.### #.### #.### ##\n",
+      "#.#...#.# # #.# # ##\n",
+      "#.#.#.#.# # #.# # ##\n",
+      "#.#.#.#.# # #.# # ##\n",
+      "#...#...#   #.....E#\n",
+      "####################\n",
+      "time: 0.00025749999986146577 ms\n",
+      "visited cells: 92\n",
+      "path length: 76\n"
+     ]
+    }
+   ],
+   "source": [
+    "maze2 = builder.buildFromFile(test_lab3)\n",
+    "\n",
+    "solver = MazeSolver(maze2, AStar(), ConsoleView())\n",
+    "print(solver.strategyName())\n",
+    "stats = solver.solve()\n",
+    "stats.show()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "2d84a151",
+   "metadata": {},
    "outputs": [],
    "source": []
   }