def buildParseTree(expression):
expList = expression.split()
empTree = BinaryTree('')
parentStack = Stack()
parentStack.push(empTree)
currentNode = empTree
for item in expList:
if item == '(':
currentNode.insertLeft('')
parentStack.push(currentNode)
currentNode = currentNode.getLeftChild()
elif item not in ['+', '-', '*', '/', ')']:
currentNode.setRootValue(int(item))
currentNode = parentStack.pop()
elif item in ['+', '-', '*', '/']:
currentNode.setRootValue(item)
currentNode.insertRight('')
parentStack.push(currentNode)
currentNode = currentNode.getRightChild()
elif item == ')':
currentNode = parentStack.pop()
else:
raise ValueError
return empTree
def iterInOrder(currentTree):
pStack = Stack()
print "\nPrinting in order traversal\n"
while currentTree != None or not pStack.isEmpty():
if currentTree !=None:
pStack.push(currentTree)
currentTree = currentTree.getLeftChild()
else:
currentTree = pStack.pop()
print currentTree.getRootValue()
currentTree = currentTree.getRightChild()
