Question

in python please

Q1) Create a Singly link list and write Python Programs for the following tasks: a. Delete the first node/item from the beginning of the link list b. Insert a node/item at the end of the link list c. Delete a node/item from a specific position in the link list

Q2) Create a Singly link list and write a Python Program for the following tasks: a. Search a specific item in the linked list and return true if the item is found and display the node position otherwise return false. b. Reverse the link list.

Answer 1

Python code

Q1)

class Node:
def __init__(self, data=None):
self.data = data
self.next = None

class PLinkedList:
def __init__(self):
self.head = None

# Function to delete node at first
def DeleteAtFirst(self):
if ( self.head is None):
print('No node')
else:
temp=self.head
self.head=self.head.next
temp=None
print('Deleted')
  
# Function to insert newnode at end
def InsertAtEnd(self, newdata):
NewNode = Node(newdata)
if self.head is None:#no node in the list
self.head = NewNode
return
temp = self.head
while(temp.next):#traverse the list up to the end of the node
temp = temp.next
temp.next=NewNode

# Function to remove node at given poistion
def DeleteNodeAtpos(self, pos):
temp = self.head
count=0 # finding position
if (self.head is not None and pos==1):# first node, positon=1
self.head = self.head.next #assign first node to next
temp = None
print('Deleted')
return
prev=self.head
flag=0
while (temp is not None):
count=count+1
if count == pos:
prev.next=temp.next
temp=None
print('Deleted')
flag=1
break
prev = temp
temp = temp.next
if flag==0:
print('No node at this position')

# Function to display the linked list

def Listdisplay(self):
temp = self.head
while (temp):
print(temp.data)
temp = temp.next

Plist = PLinkedList()
Plist.InsertAtEnd(5)
Plist.InsertAtEnd(6)
Plist.InsertAtEnd(7)
Plist.Listdisplay()
Plist.DeleteAtFirst()
Plist.Listdisplay()
Plist.DeleteNodeAtpos(2)
Plist.Listdisplay()
Plist.DeleteNodeAtpos(2)

output

5
6
7
Deleted
6
7
Deleted
6
No node at this position

screenshort of output

Q2)

class Node:
def __init__(self, data=None):
self.data = data
self.next = None

class PLinkedList:
def __init__(self):
self.head = None
  
  
# Function to insert newnode at end
def InsertAtEnd(self, newdata):
NewNode = Node(newdata)
if self.head is None:#no node in the list
self.head = NewNode
return
temp = self.head
while(temp.next):#traverse the list up to the end of the node
temp = temp.next
temp.next=NewNode
  
# This Function checks whether the value present in the linked list
def Listsearch(self, val):
  
# Initialize temp to head
temp = self.head
count=0
# loop till temp not equal to None
while temp != None:
count=count+1
if temp.data == val:
print('Found at position',count)
return True # data found
  
temp = temp.next
  
return False # Data Not found

# Function to reverse the linked list
def Reverselist(self):
prev = None
temp = self.head
while(temp is not None):
next = temp.next
temp.next = prev
prev = temp
temp = next
self.head = prev
  
# Function to display the linked list
def Listdisplay(self):
temp = self.head
while (temp):
print(temp.data)
temp = temp.next

Plist = PLinkedList()
Plist.InsertAtEnd(5)
Plist.InsertAtEnd(6)
Plist.InsertAtEnd(7)
Plist.Listdisplay()
if Plist.Listsearch(6)==False:
print('Not Found')
Plist.Reverselist()
print('List after reverse')
Plist.Listdisplay()

screenshort of output

Q1

Q2