题解 | 迷宫寻路

def solve(maze, start, end):
    def is_valid(x, y):
        return 0 <= x <len(maze) and 0 <= y <len(maze[0]) and maze[x][y]=='.'
    def dfs(x, y, path):
        if (x, y) == end:
            return path
        directions = [(1,0),(0,1),(-1,0),(0,-1)]
        for dx, dy in directions:
            new_x, new_y = x + dx , y + dy
            if is_valid(new_x, new_y) and (new_x, new_y) not in path:
                result = dfs(new_x, new_y, path +[(new_x,new_y)])
                if result:
                    return result
        return None
    return dfs(start[0], start[1],[start])
if __name__ == "__main__":
    n,m = map(int, input().split())
    maze = [list(input().strip()) for _ in range(n)]
    if solve(maze,(0,0),(n-1,m-1)):
        print('Yes')
    else:
        print('No')