/**
An interface that describes the operations of a set of objects.
@author Charles Hoot, Frank M. Carrano
@version 4.0
*/
public interface SetInterface<T>
{
/** Gets the current number of entries in this set.
@return The integer number of entries currently in the set. */
public int getCurrentSize();
/** Sees whether this set is empty.
@return True if the set is empty, or false if not. */
public boolean isEmpty();
/** Adds a new entry to this set, avoiding duplicates.
@param newEntry The object to be added as a new entry.
@return True if the addition is successful, or
false if the item already is in the set. */
public boolean add(T newEntry);
/** Removes a specific entry from this set, if possible.
@param anEntry The entry to be removed.
@return True if the removal was successful, or false if not. */
public boolean remove(T anEntry);
/** Removes one unspecified entry from this set, if possible.
@return Either the removed entry, if the removal was successful,
or null. */
public T remove();
/** Removes all entries from this set. */
public void clear();
/** Tests whether this set contains a given entry.
@param anEntry The entry to locate.
@return True if the set contains anEntry, or false if not .*/
public boolean contains(T anEntry);
/** Retrieves all entries that are in this set.
@return A newly allocated array of all the entries in the set. */
public T[] toArray();
} // end SetInterface
/**
An interface for pairs of objects.
@author Frank M. Carrano
@varsion 4.0
*/
public interface Pairable<T>
{
public T getFirst();
public T getSecond();
public void changeOrder();
} // end Pairable/**
A class of ordered pairs of objects having the same data type.
@author Frank M. Carrano
@version 4.0
*/
public class OrderedPair<T> implements Pairable<T>
{
private T first, second;
public OrderedPair()
{
} // end default constructor
public OrderedPair(T firstItem, T secondItem)
{
first = firstItem;
second = secondItem;
} // end constructor
/** Returns the first object in this pair. */
public T getFirst()
{
return first;
} // end getFirst
/** Returns the second object in this pair. */
public T getSecond()
{
return second;
} // end getSecond
/** Returns a string representation of this pair. */
public String toString()
{
return "(" + first + ", " + second + ")";
} // end toString
/** Interchanges the objects in this pair. */
public void changeOrder()
{
T temp = first;
first = second;
second = temp;
} // changeOrder
} // end OrderedPair
