Chapter 8, Problem 17E

Create a class ShuffleCipher that implements the interface MessageEncoder, as described in Exercise 15. The constructor should have one parameter caned n. Define the method encode so that the message is snuffled n times. To perform one shuffle, split the message in hair and then take characters from each half alternately. For example, if the message is abcdefghi, the halves are abcde and fghi. The shuffled message is afbgchcie. (Hint. You may wish to define a private method that performs one shuffle.)