import java.io.*;

public class PrintVisitor implements FileSystemVisitor
{
   public void visitFileNode(FileNode node)
   {
      for (int i = 0; i < level; i++) System.out.print(" ");
      System.out.println(node.getFile().getName());
   }

   public void visitDirectoryNode(DirectoryNode node)
   {
      for (int i = 0; i < level; i++) System.out.print(" ");
      System.out.println(node.getDirectory().getName());
      level++;
      for (FileSystemNode c : node.getChildren())
         c.accept(this);
      level--;
   }

   private int level = 0;
}