public class HashTreeElement (
  public class HashTreeElement {

 public final HashMap<String,HashTreeElement> children = new HashMap<String,HashTreeElement>();
 public final String key;

 public HashTreeElement(final String path) {
  int i = path.indexOf("\\");
  key = (i<0)?path:((i==0)?"":path.substring(0,i));
  if ((i>=0)&((i+1)<path.length())) {
   HashTreeElement child = new HashTreeElement(path.substring(i+1));
   children.put(child.key,child);
  }
 }

 public void add(final String path) {
  int i = path.indexOf("\\");
  String newKey = null;
  String childPath= null;
  if (i<0) {
   newKey=path;
  } else {
   newKey    = (i==0)?"":path.substring(0,i);
   childPath = path.substring(i+1);
   i = childPath.indexOf("\\");
   String childKey = (i<0)?childPath:((i==0)?"":childPath.substring(0,i));
   HashTreeElement child = this.children.get(childKey);
   if (child==null) {
    this.children.put(childKey,new HashTreeElement(childPath));
   } else {
    if (childPath.length()>(i+1)) {
     child.add(childPath);
    } 
   }
  }

//  if (!key.equals(newKey)) throw new Exception("new Tree root!");
 }
  
 public String toString(final int lvl) {
    StringBuffer res2 =new StringBuffer("\n");
    for (int i=0;i<=lvl;i++) {
     res2.append("...->");
    }
    StringBuffer res =new StringBuffer(key);
    boolean suff= true;
    for (HashTreeElement t:children.values()) {
      res.append(suff?"->":res2.toString()).append(t.toString(lvl+1));
      suff=false;
    }
    return res.toString();
 }

 public static void main(String[] args) {
  HashTreeElement root = null;
  for (String s : args) {
   if (root==null) {
    root = new HashTreeElement(s);
   } else {
    root.add(s);
   }
  }
  System.out.println(root.toString(0));
 }
}
)