package assign06;

import java.util.NoSuchElementException;

/**

* This interface specifies the general behavior of a last-in-first-out (LIFO)

* stack of elements.

*

* @author CS 2420 course staff

* @version February 20, 2025

*

* @param <E> - the type of elements contained in the stack

*/

public interface Stack<E> {

/**

* Removes all of the elements from the stack.

*/

public void clear();

/**

* Answers whether the stack is empty or contains elements.

*

* @return true if the stack contains no elements; false, otherwise.

*/

public boolean isEmpty();

/**

* Returns, but does not remove, the element at the top of the stack.

*

* @return the element at the top of the stack

* @throws NoSuchElementException if the stack is empty

*/

public E peek() throws NoSuchElementException;

/**

* Returns and removes the item at the top of the stack.

*

* @return the element at the top of the stack

* @throws NoSuchElementException if the stack is empty

*/

public E pop() throws NoSuchElementException;

/**

* Adds a given element to the stack, putting it at the top of the stack.

*

* @param element - the element to be added

*/

public void push(E element);

/**

* Gets the number of elements in the stack.

*

* @return the number of elements in the stack

*/

public int size();

}