Question

1. Create a node class and linked list class.

2. Add the following function from lecture to your linked list class

addFirst(e)

addLast (e)

add(index, e)

removeFirst

removeLast

remove(index)

3. Add the following methods to the linked list class.

a. # Return the size of the list

def getSize(self):

b. # Clear the list */

def clear(self):

c. # Return the element from this list at the specified index

def get(self, index):

Answer 1

#Python program

class Node:
def __init__(self, data):
self.data = data
self.next = None
  
# Linked List class
class LinkedList:
def __init__(self):
self.head = None

def addFirst(self , new_data):
new_node = Node(new_data)
new_node.next= self.head
self.head = new_node

def addLast(self, new_data):
new_node = Node(new_data)
  
if self.head is None:
self.head = new_node
return
last = self.head
while (last.next):
last = last.next

last.next = new_node

def add(self,index,new_data):
if(index<0 or index>self.getSize()):
return
new_node = Node(new_data)
  
if index==0:
new_node.next= self.head
self.head = new_node
return
  
last = self.head
i=1
while (last.next and i<index):
last = last.next
i=i+1
  
new_node.next = last.next
last.next = new_node

def removeFirst(self):
if(self.head is None):
return
temp = self.head
self.head = temp.next
temp=None

def removeLast(self):
new_node = Node(new_data)
  
if self.head is None:
self.head = new_node
return
  
last = self.head
if last.next is None:
last = None
return
  
prev = last
while (last.next):
prev = last
last = last.next

prev.next = last.next
last = None

def getSize(self):
count = 0
last = self.head
while last:
count = count+1
last = last.next
return count

def clear (self):
current = self.head
while current:
prev = current.next
del current.data
current = prev

def get(self , index):
if(index<0 or index>=self.getSize()):
return
current = self.head
i=0
while current and i<index:
i=i+1
current = current.next

return current.data

llist = LinkedList()
llist.addLast(7)
llist.addFirst(1)
llist.addLast(3)
llist.addFirst(2)

print(llist.getSize())
print(llist.get(2))
llist.add(2,5)
print(llist.get(2))