/**
 * Interface for Dictionary.
 */
interface Dictionary<AnyType> 
{

	/**
     * Test if the Dictionary is logically 
     * empty (contains no valid values).
     * @return true if empty, false otherwise.
     */
	public boolean isEmpty();
   
	/**
     * Return number of elements inserted into the Dictionary 
     * @return number of Items in the Dictionary (i.e. "N").
     */
	public int numElements();
	
	/**
     * Find an item in the Dictionary.
     * @param A the item to search for.
     * @return true if found.
     */
    public boolean contains(AnyType A);
    
    /**
     * Insert into the Dictionary; duplicates are ignored.
     * @param A the item to insert.
     */
    public void insert(AnyType A);
   
    /** 
     * Resets the internal statistic counters to zero.
     */
	public void resetStats();
	
	/**
     * Return the requested statistic for a given data structure:
     * @param statistic requested, as follows:
     * For all data structures:
     * 1 = Number of locations examined (Excluding the location
     * an Item was found/placed.)
     * For Trees:
     * 2 = Tree Height
     * For Hash Tables:
     * 2 = Number of empty buckets
     * 3 = TableSize
     * @return the requested statistic.
     */
	public int returnStats(int statType);
	
}