TraversalDemo.java.html

  1  import java.util.Iterator;
  2  
  3  /**
  4     This program demonstrates tree traversal.
  5  */
  6  public class TraversalDemo
  7  {
  8     public static void main(String[] args)
  9     {
 10        Tree t1 = new Tree("Anne");
 11        Tree t2 = new Tree("Peter");
 12        t1.addSubtree(t2);
 13        Tree t3 = new Tree("Zara");
 14        t1.addSubtree(t3);
 15        Tree t4 = new Tree("Savannah");
 16        t2.addSubtree(t4);
 17  
 18        // Count short names with visitor
 19        class ShortNameCounter implements Tree.Visitor
 20        {
 21           public int counter = 0;
 22           public void visit(Object data)
 23           {
 24              System.out.println(data);
 25              if (data.toString().length() <= 5) { counter++; }
 26           }
 27        }
 28  
 29        ShortNameCounter v = new ShortNameCounter();
 30  
 31        t1.preorder(v);
 32        System.out.println("Short names: " + v.counter);
 33  
 34        // Count short names with iterator
 35        Iterator iter = t1.iterator();
 36        int counter = 0;
 37        while (iter.hasNext())
 38        {
 39           Object data = iter.next();
 40           System.out.println(data);
 41           if (data.toString().length() <= 5) { counter++; }
 42        }
 43        System.out.println("Short names: " + counter);         
 44     }
 45  }