/**
   A class for vertices of a graph.  This class is
   mutable only in that vertices may be marked or unmarked.
   Vertices have, in addition to marks, numbers and names
   that may be accessed.
*/

public class Vertex
{

   // a numerical index that may be used for
   //   adjacency matrices or adjacency list
   int number;

   // a mark that may be used in traversal
   boolean mark=false;

   // the name of the vertex
   String name;


   /** construct a vertex with a given name
       and a given index
       @param s the name
   */

   public Vertex(String s, int n)      {
     name=s;
     number=n;                         }


   /**
      @return the index of the vertex
   */

   public int getNumber()              {
     return number;                    }


   /**
      @return the name of the given vertex
   */
   public String getName()             {
     return name;                      }


   /**
      @return a string representation of
       the name of the vertex
   */

   public String toString()            {
     return name;                      }


   /** mark the given vertex
   */

   public void mark()                  {
     mark=true;                        }


   /** unmark the given vertex
   */

   public void unmark()                {
     mark=false;                       }



   /** determine whether the vertex is marked
   */


   public boolean isMarked()           {
     return mark;                      }

};