A TrainComposition is built by attaching and detaching wagons from the left and the right sides.
For example, if we start by attaching wagon 7 from the left followed by attaching wagon 13, again from the left, we get a composition of two wagons (13 and 7 from left to right). Now the first wagon that can be detached from the right is 7 and the first that can be detached from the left is 13.
Implement a TrainComposition that models this problem.
- Example case: Exception
- Several wagons: Exception
- Performance test with a large number of wagons: Exception