There is a robot that can help fetch coffee to staffs in an office. Now, suppose you are developing an algorithm for this robot to achieve this task. Please look at the office map below. On the map, the number represents the ID of a Tile. The solid lines represent impenetrable walls. At the start, this robot is at Tile 1. Please help the robot fetch the coffee at the Tile 20 by planning a route for it based on the state-space searching algorithms we have learned. (1) Please discuss how you can solve this problem by using depth-first search (DFS) algorithm. Please write down step by step procedure of the searching algorithm, as well as the final solution searched by DFS.
