def make_two_way(singlyll):
if singlyll == None:
return (None, None)
temp = singlyll
doublyll = TwoWayNode(temp.data)
temp2 = doublyll
while temp.next != None:
temp = temp.next
new_node = TwoWayNode(temp.data, previous=doublyll)
doublyll.next = new_node
doublyll = doublyll.next
return (temp2, doublyll)
def append(self, data):
node = TwoWayNode(data)
if self.head == None:
self.head = node
self.head.next = self.head
self.tail = self.head
self.size += 1
else:
probe = self.head
while probe.next != self.head:
probe = probe.next
probe.next = node
node.next = self.head
node.previous = probe
self.tail = node
self.size += 1
def enqueue(self, data):
new_node = TwoWayNode(data)
if self.count == 0:
self.head = new_node
self.head.next = self.head
self.tail = self.head
else:
probe = self.head
while probe.next != self.head:
probe = probe.next
probe.next = new_node
new_node.next = self.head
new_node.previous = probe
self.tail = new_node
self.count += 1