Problem solving task

The airplane
You are navigating an airplane, which can take a series of commands:
• up X increases the direction by X units
• down X decreases the direction by X units
• forward X increases the horizontal position by X units and the vertical
position by X multipled by the current direction
Here is an example of a preplanned course:
forward 4
up 2
forward 8
down 1
forward 2
up 3
forward 3
These instructions would do the following (with the initial position and direction
set to 0):
• Increase the horizontal position by 4 (as your direction is 0, the vertical
position stays unchanged)
• Increase the direction by 2
• Increase the horizontal position by 8 and vertical position by 16 (as the
direction is 2, the vertical position becomes the previous value 0 + 2 * 8
= 16)
• Decrease the direction by 1
• Increase the horizontal position by 2 and vertical position by 2 (as the
direction is 1, the vertical position becomes the previous value 16 + 1 * 2
= 18)
• Increase the direction by 3
• Increase the horizontal position by 3 and vertical position by 12
This course would result in a horizontal position of 17 and a vertical position of
30.
Create a program that reads the preplanned course from a file (e.g. a file
containing the preplanned course above), calculates the horizontal and vertical
position after following the course and then multiplies the final horizontal position
by the final vertical position. In this case that would be 17 * 30 = 510.
Sumbit the code for calculating the above scenario.


It should be
• Easy to extend the code with additional commands, could for example
be a dive command where “dive 4” would instantly decrease the vertical
position by 4
• Unit tests
• Readable code that is easy to follow