(Solved): Q4. Suppose two friends live in different cities on a map, such as the Romania map shown in Slide. ...

Q4. Suppose two friends live in different cities on a map, such as the Romania map shown in Slide. On every turn, we can simultaneously move each friend to a neighboring city on the map. The amount of time needed to move from city \( i \) to neighbor \( j \) is equal to the road distance \( d(i, j) \) between the cities, but on each turn the friend that arrives first must wait until the other one arrives (and calls the first on his/her cell phone) before the next turn can begin. We want the two friends to meet as quickly as possible. (3 points each) a. What is the state space? b. What is the Goal? To get both friends in the same city, with the shortest overall time traveled. c. What is the Successor function? d. What is the step cost function?