Create cycling groups.

import java.util.*;
import java.io.*;
/**
 * Create cycling groups.
 */
public class RidingGroup implements Iterable<HashSet<String>>
{
    private List<HashSet<String>> groups;

    /** Constructor for Riding Group */
    public RidingGroup()
    {
        // initialize the category map
        groups = new ArrayList<HashSet<String>>();
        // Create an entry in the map for each skill
        for (Distance dist: Distance.values())
        {
            // Each group is associated with a set of cyclist names
            groups.add(new HashSet<String>());
        }
    }


    /** Read the cyclist data from an input stream and create the list.
     * @return List of cyclists from whom to form groups.
     */
    public void load(Scanner input)
    {
        // Read all input
        while(input.hasNext())
        {
            //the first token will be the name
            String name = input.next();
            Distance distance = Distance.valueOf(input.next());
            // categorize the riders by distance
            groups.get(distance.ordinal()).add(name);
        }
    }
    /** Accessor to an iterator over the groups */
    public Iterator<HashSet<String>> iterator()
    {
        return groups.iterator();
    }
    /** Local main for testing */
    public static void main(String[] args) throws java.io.IOException
    {
        // Open standard input for reading the text
        RidingGroup rg = new RidingGroup();
        rg.load(new Scanner(System.in));
        //rg.createGroups(list);
        Iterator<HashSet<String>> iter = rg.iterator();
        for (Distance dist: Distance.values())
        {
            System.out.println(dist);
            System.out.println(iter.next());
        }

    }
}
/** Enumerated type for riding distances */
enum Distance
{
  easy, moderate, lengthy, century, centuryplus;
}