COSC 311  Homework 11/7/2016  Compute balance of BST (at root)  
Distributed 11/7/2016
Due: 11/14/2016

Balance at a node =  
  node is a leaf:   0
  else:             height of right child - height of left child
  
Height of a node =
   node is a leaf:  0
   else:            1 + max (height of right child, height of left child)

(1) Implement a recursive solution to the problem of computing the balance of
the root node of a binary search tree.  

(2) Give the output when run on the following data, inserted in order, 
10, 5, 15, 3, 13, 17, 18, 22, 21


Turn in:
  Hardcopy of your code.
  Hardcopy of test run on above data
  In your code, include a header:
      [your name]
      [URL of code]
      COSC 311
      HW 1107
      FALL 2016.
  Do not supply UML diagram for your code.