Written by Nornubari Kanabolo MST DM

Special Case 2.3(T-intersection) continued

As Matt explained in the previous post, for 2 robots at a T-intersection:

“In this case the robot that is within the intersection (in the middle of the T – intersection) has the lowest priority and must move out of the way of the other robots (if the other robots are in the path of the low priority robot). The lowest priority robot will step down the hallway that is not blocked and then wait for the other robot to pass.”

As for the case with 3 robots at the intersection, the following method could be used:

Say R2 steps into the intersection and R1 needs to go where R2 is and R2 needs to go where R3 is. One thing that could happen is R3 goes back to the last intersection to wait and R2 waits 5 seconds to move one square to the right.

At this point, 2 possible cases could happen. Case 1 as follows:

R1 waits 5 seconds and sees that there is no one in the intersection now then moves into the intersection, so that it can go to the hallway where R2 was. R2 waits another 7 seconds and goes down to where R1 was. R3 waits 3 seconds and returns back to where it originally was.

Or if R2 needs to go where R3 is then Case 2 is enacted as follows:

Since there are no longer 3 robots at the intersection and it is now just 2 at an intersection, the rules for encounters 2.3 as stated by Matt are used.