12.7

  1. It fails if the list is empty.
  2.  
    public Tree (int a, int b, int c)
{
   Node left = new Node(b,null,null);
   Node right = new Node(c,null,null);
   root = new Node (a,left,right);
}
  3.  
    public void insert27()
{
   Node newNode = new Node();
   newNode.info = 27;
   newNode.link = current.link;
   current.link = newNode;
}