import java.util.*;
/**
* The StrangeDataStructure
interface specifies the
* behavior (interface) of a data structure. This data structure
* accepts integers (via the addElement()
method
* and stores them internally.
* Any object that implements interface StrangeDataStructure
* must implement the methods below.
*
*/
public interface StrangeDataStructure {
/**
* addElement
should take the argument
* and store that internally. You can use whatever data
* structure you like for the internal storage of these integers.
*
* @param k an int
value
*/
public void addElement (int k);
/**
* Method getSumOfElements
should return the sum
* of the integers stored.
*
* @return an int
value
*/
public int getSumOfElements ();
/**
* Method oddElements
should return an
* Enumeration
of ONLY the odd integers stored.
*
* @return an Enumeration
value
*/
public Enumeration oddElements ();
/**
* Method evenElements
should return an
* Enumeration
of ONLY the odd integers stored.
*
* @return an Enumeration
value
*/
public Enumeration evenElements ();
}