Visit Leaves In-orderby Isai Damier, Android Engineer @ Google

```  #=====================================================================
# Author: Isai Damier
# Title: Visit Leaves In-order
# Project: geekviewpoint
# Package: algorithms
#
# Statement:
#   Visit/Print the leaves of this BST in order.
#
# Time Complexity of Solution:
#   Best = Average = Worst = O(n).
#
# Alternate Algorithm: recursive:
#
#     def leavesInorder(self):
#       leavesInorder(self.root)
#
#     def leavesInorder(self, n):
#       if n is not None:
#         leavesInorder(n.left)
#         if n is None.left and n is None.right: # isLeaf()
#            self.visit(n)
#         leavesInorder(n.right)
#
#=====================================================================

from Queue import LifoQueue

class BST( object ):

def __init__( self ):
self.root = None

def getRoot( self ):
return self.root

def leavesInorder( self ):
stack = LifoQueue()
n = self.root
while n is not None or not stack.empty():
if n is not None:
stack.put( n )
n = n.left
else:
n = stack.get()
if n.left is None and n.right is None: # isLeaf()
self.visit( n )
n = n.right
```
```import unittest
from algorithms.BST import BST
from cStringIO import StringIO
import sys
class Test( unittest.TestCase ):
#===================================================================
# Test of leavesInorder method, of class BST.
# draw the tree on paper for visual
#===================================================================
def testLeavesInorder( self ):
bst = BST()
old_stdout = sys.stdout
result = sys.stdout = StringIO()

expected = ""
self.assertEquals( expected, result.getvalue() )
expected = "35\n75\n125\n175\n212\n275\n312\n400\n"

treeTape = [200, 100, 300, 50, 150, 250, 350, 25, 75, 125,
175, 225, 275, 325, 375, 35, 212, 312, 400]
for i in treeTape: