Interview Question for Java Engineer at Nextlabs:

/***************************************************************************
* INSERT
 ****************************************************************************/
public void insert(T data)
{
    root = insert(root, data);
}
private Node<T> insert(Node<T> p, T toInsert)
{
    if (p == null)
       return new Node<T>(toInsert);
    if (toInsert.compareTo(p.data) == 0)
        return p;

    if (toInsert.compareTo(p.data) < 0)
        p.left = insert(p.left, toInsert);
    else
        p.right = insert(p.right, toInsert);

    return p;
}

/***************************************************************************
* FIND MIN
 ****************************************************************************/
public void findMin( )
{
    return findMin(root);
}
private Node<T> findMin( Node<T> t )
{
    if( t == null )
        return null;
    else if( t.left == null )
        return t;
    return findMin( t.left );
}
/***************************************************************************
* CONTAINS
 ****************************************************************************/
public boolean contains(T data)
{
   return contains(root, data);
}
private boolean contains(Node<T> p, T toSearch)
{
   if (p == null)
      return false;
   else
      if (toSearch.compareTo(p.data) == 0)
          return true;
      else if (toSearch.compareTo(p.data) < 0)
         return search(p.left, toSearch);
      else
         return search(p.right, toSearch);
}

/***************************************************************************
* REMOVE
 ****************************************************************************/

public void remove(T data)
{
    root = remove(root, data);
}
private Node<T> remove(Node<T> p, T d)
{
    if (p == null)
        throw new RuntimeException("cannot be remove.");
    else if (d.compareTo(p.data) < 0)
        p.left = delete (p.left, d);
    else if (d.compareTo(p.data) > 0)
        p.right = delete (p.right, d);
    else
    {
        if (p.left == null)
            return p.right;
        else if (p.right == null)
            return p.left;
        else
        {
             Node<T> tmp = new Node<T>(retrieveData(p.left));
             tmp.left = delete(p.left, tmp.data) ;
             tmp.right = p.right;
             p = tmp;
        }
    }
    return p;
}
private T retrieveData(Node<T> p)
{
    while (p.right != null) p = p.right;
    return p.data;
}