Imagine a rectangular grid with a robot standing on a grid square, called a cell. The object of the exercise is to get the robot to collect the coins on the grid as efficiently as possible. Our robot can move either backwards (B) or forward (F) and may turn either 90º to the right (R) (clockwise) or 90º to the left (L) (counter-clockwise). The grid may have cells blocked off that the robot can not move into.
Figure 1: Simple Example (B01)
For example, let’s look at the example, above. The very simple robot is represented as a hungry blue ball. The robot’s eyes and mouth point in the forward direction. To move to the coin we need to:
- Turn Left
- Go Forward
- Turn Right
- Go Forward
- Go Forward
In the RoboWOKI language we would write this as LFRFF or as lfrff.
There are other ways that the robot may have moved to the coin, but the object of the puzzle is for you to find the most efficient (shortest) path.
This is an example of sequence. In a sequence “an action, or event, leads to the next ordered action in a predetermined order.” https://www.webopedia.com/definitions/sequence/ We can see that the robot has to perform a group of tasks, one after the other, also we can see that the order of the steps is vitally important.
Here is a second example of sequence.
If you look at the situation above you can see that there are actually two sequences that the robot may take that are the same length.
 FLFRFFRFFLFF |  LFRFFFRFFLFF |
In the first solution the robot goes forward then turns left and in the second solution the robot turns to the left first and then goes forward. Both of these solutions are the same length.