def prepend(self, data):
if self.head == None:
self.head = Node(data)
else:
new_head = Node(data)
new_head.next = self.head
self.head = new_head
def insert_after(self, locdata, data):
node = Node(data)
curr = self.head
while curr.data != locdata and curr.next:
curr = curr.next
node.next = curr.next
curr.next = node
def push(self, new_data):
# Create new node
new_node = Node(new_data)
# Make next of new node as head
new_node.next = self.head
# Point new node the head node
self.head = new_node
def insert_at_head(self, data):
if self.head is None:
self.head = Node(data)
return
node = Node(data)
self.head.prev = node
node.next = self.head
self.head = node
def insert_at_pos(self, pos, data):
node = Node(data)
curr = self.head
count = 1
while count != pos and curr.next:
curr = curr.next
count += 1
node.next = curr.next
curr.next = node
def add_to_front(self, item):
temp = Node(item)
if self.back == None:
self.back = self.front = temp
return
oldfront = self.front
self.front = temp
temp.next = oldfront
self.n += 1
def createList(iterator) -> Node:
'''
Create a link list with None head and keep the order.
'''
head = Node(None, None)
head.next = head
probe = head
for data in iterator:
probe.next = Node(data, head)
probe = probe.next
# node head
return head
def insertAfter(self, prev_node, new_data):
# Check if the given prev_node exists
if prev_node is None:
print("Prev node must be in list")
return
# Create a new node
new_node = Node(new_data)
# Make next of new node as next of prev_node
new_node.next = prev_node.next
prev_node.next = new_node
def insert_at(self, item, i):
insert = Node(item)
if i == 0:
self.add_to_front(item)
return
elif i > self.n:
self.add_to_back(item)
return
x = 0
curr = self.front
while x < i - 1: # get left neighbor
curr = curr.next
x += 1
next_one = curr.next
curr.next = insert
insert.next = next_one
self.n += 1
def insert_at_head(self, data):
node = Node(data)
node.next = self.head
self.head = node
