// Textbook fragment 08.06
import java.util.Comparator;
/** Implementation of a priority queue by means of a sorted node list. */
public class SortedListPriorityQueue<K,V> implements PriorityQueue<K,V> {
  protected PositionList<Entry<K,V>> entries;
  protected Comparator<K> c;
  protected Position<Entry<K,V>> actionPos; // variable used by subclasses
  /** Inner class for entries */
  protected static class MyEntry<K,V> implements Entry<K,V> {
    protected K k; // key
    protected V v; // value
    public MyEntry(K key, V value) {
      k = key;
      v = value;
    }
    // methods of the Entry interface
    public K getKey() { return k; }
    public V getValue() { return v; }
  }
  /** Creates the priority queue with the default comparator. */
  public SortedListPriorityQueue () {
    entries = new NodePositionList<Entry<K,V>>();
    c = new DefaultComparator<K>();
  }
  /** Creates the priority queue with the given comparator. */
  public SortedListPriorityQueue (Comparator<K> comp) {
    entries = new NodePositionList<Entry<K,V>>();
    c = comp;
  }