106 lines
2.7 KiB
Python
106 lines
2.7 KiB
Python
######################################
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# DCS 229 -- TurtleDFS
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# Depth-First Search implementation for Turtle Maze
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# Date: 03/29/2026
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# Name: Benjamin Adovasio
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# Resources Used: I worked with Pat Cohen on the project.
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##########################################
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import os
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from Stack import Stack
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from TurtleMaze import TurtleMaze, Cell, Contents
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def get_neighbors(maze: TurtleMaze, cell: Cell) -> list[Cell]:
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'''returns a list of non-obstacle neighbors in north, south, east, west order'''
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neighbors = []
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row = cell.y
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col = cell.x
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# north
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if row - 1 >= 0:
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north = maze[row - 1][col]
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if not north.isBlocked():
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neighbors.append(north)
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# south
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if row + 1 < len(maze.maze_grid):
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south = maze[row + 1][col]
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if not south.isBlocked():
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neighbors.append(south)
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# east
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if col + 1 < len(maze[0]):
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east = maze[row][col + 1]
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if not east.isBlocked():
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neighbors.append(east)
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# west
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if col - 1 >= 0:
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west = maze[row][col - 1]
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if not west.isBlocked():
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neighbors.append(west)
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return neighbors
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def dfs(maze: TurtleMaze) -> bool:
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'''runs a non-recursive depth first search on the maze with backtracking
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Returns:
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True if the goal is found, False otherwise
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'''
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stack = Stack()
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start = maze.getStart()
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visited = set()
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stack.push(start)
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visited.add((start.y, start.x))
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maze.updatePosition(start)
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while not stack.is_empty():
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current = stack.peek()
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# if we reached the goal, we are done
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if current.isGoal():
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return True
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found_next = False
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# look for an unvisited neighbor
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for neighbor in get_neighbors(maze, current):
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if (neighbor.y, neighbor.x) not in visited:
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neighbor.setParent(current)
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visited.add((neighbor.y, neighbor.x))
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stack.push(neighbor)
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if not neighbor.isGoal():
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maze.updatePosition(neighbor, Contents.TRIED)
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else:
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maze.updatePosition(neighbor)
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found_next = True
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break
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# if no unvisited neighbor exists, backtrack
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if not found_next:
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dead_end = stack.pop()
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if dead_end != start and not dead_end.isGoal():
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maze.updatePosition(dead_end, Contents.DEAD_END)
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if not stack.is_empty():
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maze.updatePosition(stack.peek())
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return False
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def main():
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maze = TurtleMaze('maze_1.txt')
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start = maze.getStart()
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print("Start cell:", start)
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neighbors = get_neighbors(maze, start)
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print("Neighbors of start:", neighbors)
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if __name__ == "__main__":
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main() |