BST Is Empty
by Isai Damier, Android Engineer @ Google

  #=====================================================================
  # Author: Isai Damier
  # Title: Is Empty
  # Project: geekviewpoint
  # Package: algorithms
  #
  # Time Complexity of Solution:
  #   Best = Average = Worst = const.
  #
  #=====================================================================
 
 
class BST( object ):

  def __init__( self ):
      self.root = None


  def getRoot( self ):
    return self.root

  def isEmpty( self ):
    return self.root is None

import unittest
from algorithms.BST import BST
from cStringIO import StringIO
import sys
class Test( unittest.TestCase ):
  #=====================================================================
  # Test of isEmpty method, of class BST.
  #=====================================================================
  def testIsEmpty( self ):
    bst = BST()

    expResult = True
    result = bst.isEmpty()
    self.assertEquals( expResult, result )
    bst.add( 5 )
    result = bst.isEmpty()
    expResult = False
    self.assertEquals( expResult, result )