inspectablebinarytree.java

真的很麻烦也

public interface InspectableBinaryTree
    extends InspectableTree {
  // accessor methods
  /** return the left child of a node */
  public Position leftChild(Position v);
  /** return the right child of a node */
  public Position rightChild(Position v);
  /** return the sibling of a node */
  public Position sibling(Position v);
}