Turn in Friday 9/18

1. Add a recursive function to "flip" the stack developed in class. That is, the order of the items in the stack should be reversed after this function is called, with the top being the former bottom, the bottom being the former top, the second to the top being the former second from the bottom, etc. Test your code and turn in a printout of the function code.

2. Modify the display function from the binary search tree written in class so that the items in the tree are displayed in alphabetical order. Test your code and turn in a printout of your function.

3. Implement a queue data structure with the public operations:

a. void enque(string s)

b. string dequeue()

c. bool empty()

Implement your queue using 2 separate stacks (you may use the stack class we developed in class). Make your implementation fast such that any sequence of n enqueue and dequeue commands will take O(n) run time in total. Turn in the printout along with an argument as to why your implementation is O(n) for any sequence of n operations.

4. 4.19