A data-structure often associated with the queue is the stack. That's because they are basically the opposite of one another. While the queue works on the FIFO-principle the stack works on the LIFO-principle (Last in first out).
Similar two the queue we have three basic operations, but they are called different to distinguish between the stack and the queue. - We put something at the top of the stack. That is called push. - We take something from the top of the stack. That is called pop. - As with the queue we sometimes one to just take a look at the top of the stack. So a peak operation is nice, but not necessary
Stacks are useful data-structures for parsing or when you want follow some data to the end and then back trace to a previous state, like in depth-fist-search. These are just some use cases for stacks, but they have many more.
Your task is to implement the push, pop and peak functions for the stack.
DEFAULT OUTPUT NOT OVERWRITTEN- There has been an error with this exercise.