def insert(head, index, value):
if index < 0:
return head
if not head and index > 0:
return head
if index == 0:
new = Node(value=value)
new.next = head
head = new
return head
node = head
prev = None
step = 0
while node and step < index:
prev = node
node = node.next
step += 1
if not node:
return head
next = prev.next
new = Node(value=value)
prev.next = new
new.next = next
return head
def insert_before_value(self, value, x):
'''
This function is used to add element before given value
params:
value: any type
x : any type
'''
if self.head is None:
raise Exception("List has no items")
new_node = Node(value)
# if first node has matched condition
if self.head.data == x:
new_node.next = self.head
self.head = new_node
return
prev = self.head
while prev:
if prev.next.data == x:
break
prev = prev.next
if prev is None:
raise Exception("{} not exists in list".format(x))
new_node.next = prev.next
prev.next = new_node
def push(self, value):
'''
This function is used to add element at the beginning
params:
value: any type
'''
new_node = Node(value)
new_node.next = self.head
self.head = new_node
return
def insert_after_value(self, value, x):
'''
This function is used to add element after given value
params:
value: any type
x : any type
'''
if self.head is None:
raise Exception("List has no items")
new_node = Node(value)
current = self.head
while current:
if current.data == x:
break
current = current.next
if current is None:
raise Exception("{} not exists in list".format(x))
new_node.next = current.next
current.next = new_node