def _postorder_iter(node, func):
from pyds.stack.linkstack import LinkStack
stack = LinkStack([])
prior = None
while not stack.is_empty or node:
if node:
stack.push(node)
node = node.left
elif stack.top().right != prior:
node = stack.top().right
prior = None
else:
prior = stack.pop()
func(prior.data)
def _preorder_iter_linkstack(node, func):
from pyds.stack.linkstack import LinkStack
stack = LinkStack([])
stack.push(node)
while not stack.is_empty:
current_node = stack.pop()
func(current_node.data)
if current_node.right:
stack.push(current_node.right)
if current_node.left:
stack.push(current_node.left)