Program 1
# Implemenation of Circular linked list
class Node:
def __init__(self):
self.data=None
self.add=None
class CircularLinkedList:
def __init__(self):
self.start=None
self.count=0
# create list
def createList(self):
n=int(input("Enter an element"))
self.start=Node()
self.start.data=n
self.start.add=self.start
temp=self.start
self.count=self.count+1
choice=input("Want to continue")
while(choice=="Y" or choice=="y"):
n=int(input("Enter next element"))
newnode=Node()
newnode.data=n
newnode.add=self.start
temp.add=newnode
temp=temp.add
self.count=self.count+1
choice=input("Want to continue")
# Display list
def displayList(self):
if(self.start==None):
print("List not found")
else:
temp=self.start
while(True):
print(temp.data,end=" ")
temp=temp.add
if(temp==self.start):
break
print("\nTotal Node is : ",self.count)
# insert first node
def insertFirst(self):
if(self.start==None):
print("List not found")
else:
n=int(input("Enter an element"))
newnode=Node()
newnode.data=n
newnode.add=None
last=self.start
while(last.add!=self.start):
last=last.add
newnode.add=self.start
self.start=newnode
last.add=self.start
self.count=self.count+1
# insert last node
def insertLast(self):
if(self.start==None):
print("List not found")
else:
n=input("Enter an element for insert")
newnode=Node()
newnode.data=n
newnode.add=None
last=self.start
while(last.add!=self.start):
last=last.add
last.add=newnode
newnode.add=self.start
self.count=self.count+1
# insert middle node
def insertMiddle(self):
if(self.start==None):
print("List is empty")
else:
n=int(input("Enter an element for insert"))
newnode=Node()
newnode.data=n
newnode.add=None
pos=int(input("Enter the position"))
if(pos>self.count):
print("Invalid position")
else:
i=1
next=self.start
while(i<pos):
prev=next
next=next.add
i=i+1
prev.add=newnode
newnode.add=next
self.count=self.count+1
# delete first node
def deleteFirst(self):
if(self.start==None):
print("List not found")
else:
last=self.start
while(last.add!=self.start):
last=last.add
temp=self.start
self.start=self.start.add
last.add=self.start
print("Deleted node is: ",temp.data)
temp.add=None
temp=None
self.count=self.count-1
# Delete node from Middle
def deleteMiddle(self):
if(self.start==None):
print("List is empty")
else:
pos=int(input("Enter the position for delete"))
if(pos>self.count):
print("Invalid position")
else:
i=1
next=self.start
while(i<pos):
prev=next
next=next.add
i=i+1
temp=next
next=next.add
prev.add=next
print("Deleted node is: ",temp.data)
temp=None
self.count=self.count-1
# delete last node
def deleteLast(self):
if(self.start==None):
print("List not found")
else:
last=self.start
while(last.add!=self.start):
prev=last
last=last.add
prev.add=self.start
print("Deleted Node is :",last.data)
last.add=None
last=None
self.count=self.count-1
# Main Method
mylist=CircularLinkedList()
while(1):
print("\n----------------------Circular Linked List Menu--------------\n")
print("1.Create")
print("2.Display")
print("3.Insert First")
print("4.Insert Middle")
print("5.Insert Last")
print("6.Delete First")
print("7.Delete Middle")
print("8.Delete Last")
print("9.Exit")
print("\n------------------------------------------------------------\n")
choice=int(input("Enter your choice"))
if(choice==1):
mylist.createList()
elif(choice==2):
mylist.displayList()
elif(choice==3):
mylist.insertFirst()
elif(choice==4):
mylist.insertMiddle()
elif(choice==5):
mylist.insertLast()
elif(choice==6):
mylist.deleteFirst()
elif(choice==7):
mylist.deleteMiddle()
elif(choice==8):
mylist.deleteLast()
else:
break
