def postOrderTraversial(root):
buffer = Stack()
arraylist = []
node = root
buffer.push(node)
node = node.leftChild
while(node != None):
buffer.push(node)
node = node.leftChild
while(buffer.isEmpty() is False):
node = buffer.peek()
if(node.rightChild != None and node.rightChild.visited is False): # We have to set a visited flag that make the
node = node.rightChild # nodes will not visit multiple times.
while(node != None):
buffer.push(node)
parent = node
node = node.leftChild
if(parent.rightChild == None):
arraylist.append(parent.key)
parent.visited = True
buffer.pop()
else:
node.visited = True # Set visited flags
arraylist.append(node.key)
buffer.pop()
return arraylist
def inOrderTraversial(root):
arraylist = []
buffer = Stack()
node = root
# buffer.push(node)
# node = node.leftChild
# while(node != None):
# buffer.push(node)
# node = node.leftChild
#
# while(buffer.isEmpty() is False):
# node = buffer.pop()
# arraylist.append(node.key)
# if(node.rightChild != None):
# node = node.rightChild
# while(node != None):
# buffer.push(node)
# node = node.leftChild
#
# return arraylist
#
while (buffer.isEmpty() is False or node != None):
if (node != None):
buffer.push(node)
node = node.leftChild
else:
node = buffer.pop()
arraylist.append(node.key)
node = node.rightChild
return arraylist
def checkBST(root):
list = []
stack = Stack()
node = root
# stack.push(node)
while(stack.isEmpty() is False or node != None):
if(node != None):
stack.push(node)
node = node.leftChild
else:
node = stack.pop()
list.append(node.key)
node = node.rightChild
print list
return checkOrder(list)