import java.io.File;
import java.util.ArrayList;
import java.util.Comparator;

import javax.swing.JFileChooser;

/*
 * Created on Oct 29, 2004
 *
 */

/**
 * @author Owen Astrachan
 *
 */
public class PQDemo {
    private static JFileChooser ourChooser = new JFileChooser(".");
    
    private static class Reverser implements Comparator{

        public int compare(Object o1, Object o2) {
            return -1 * ((Comparable) o1).compareTo(o2);
        }
        
    }
    public static void print(PriorityQueue pq){
        while (pq.size() > 0){
            System.out.println(pq.remove());
        }
    }
    
    public static void main(String[] args){
        
        int retval = ourChooser.showOpenDialog(null);

        if (retval == JFileChooser.APPROVE_OPTION){
            File f = ourChooser.getSelectedFile();  
            Scanner s = new Scanner(f);
            ArrayList list = new ArrayList();
            
            while (s.hasNext()){
                list.add(s.next());
            }
            System.out.println("read # words = "+list.size());
            PriorityQueue pq = new PriorityQueue();
            pq.addAll(list);
            print(pq);
            
            System.out.println("\n reversed \n");
            PriorityQueue rpq = new PriorityQueue(new Reverser());
            rpq.addAll(list);
            print(rpq);
            
        }
        else {
            System.out.println("operation cancelled");   
        }
        System.exit(0);
    }
}