Program 1
# implementation of doubly Circular Linked list
class Node:
def __init__(self):
self.ladd=None
self.data=None
self.radd=None
class CircularDoubleList:
def __init__(self):
self.start=None
self.count=0
# method for create list
def createList(self):
n=int(input("Enter an element"))
self.start=Node()
self.start.ladd=None
self.start.data=n
self.start.radd=None
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.ladd=None
newnode.data=n
newnode.radd=None
temp.radd=newnode
newnode.ladd=temp
self.start.ladd=newnode
newnode.radd=self.start
temp=temp.radd
self.count=self.count+1
choice=input("Want to continue: ")
# method for display
def displayList(self):
if(self.start==None):
print("List not found")
else:
temp=self.start
print()
while(1):
print(temp.data,end=" ")
temp=temp.radd
if(temp==self.start):
break
print("\nTotal Node is : " ,self.count)
# method for reverse display
def reversedisplayList(self):
if(self.start==None):
print("List not found")
else:
temp=self.start.ladd
temp1=self.start.ladd
while(1):
print(temp.data,end=" ")
temp=temp.ladd
if(temp==temp1):
break
# method for insert first
def insertFirst(self):
if(self.start==None):
print("List not found")
else:
last=self.start
last=last.ladd
n=int(input("Enter an element for insert"))
newnode=Node()
newnode.ladd=None
newnode.data=n
newnode.radd=None
newnode.radd=self.start
self.start=ladd=newnode
self.start=newnode
self.start.ladd=last
last.radd=self.start
self.count=self.count+1
# method for insert last
def insertLast(self):
if(self.start==None):
print("List not found")
else:
last=self.start.ladd
n=int(input("Enter an element"))
newnode=Node()
newnode.ladd=None
newnode.data=n
newnode.radd=None
last.radd=newnode
newnode.ladd=last
self.start.ladd=newnode
newnode.radd=self.start
self.count=self.count+1
# Method for delete last
def deleteLast(self):
if(self.start==None):
print("List not found")
else:
temp=self.start.ladd
prev=temp.ladd
self.start.ladd=prev
prev.radd=self.start
print("Delete node is: ",temp.data)
temp.ladd=None
temp.radd=None
temp=None
self.count=self.count-1
# Method for delete middle node
def deleteMiddle(self):
if(self.start==None):
print("List not found")
else:
pos=int(input("Enter middle position for delete"))
if(pos>self.count):
print("Invalid postion total node is: ",self.count)
else:
i=1
temp=self.start
while(i<pos):
temp=temp.radd
i=i+1
prev=temp.ladd
next=temp.radd
prev.radd=next
next.ladd=prev
print("Deleted node is:",temp.data)
temp.radd=None
temp.ladd=None
temp=None
self.count=self.count-1
# Method for delete First
def deleteFirst(self):
if(self.start==None):
print("List not found")
else:
temp=self.start
last=self.start.ladd
self.start=self.start.radd
self.start.ladd=last
last.radd=self.start
print("Deleted node is: ",temp.data)
temp.ladd=None
temp.radd=None
temp=None
self.count=self.count-1
#Method for insert middle position
def insertMiddle(self):
if(self.start==None):
print("List not found")
else:
n=int(input("Enter an element for insert at middle"))
newnode=Node()
newnode.ladd=None
newnode.data=n
newnode.radd=None
pos=int(input("Enter middle position"))
if(pos>self.count):
print("Invalid position total node only: ",self.count)
else:
i=1
next=self.start
while(i<pos):
prev=next
next=next.radd
i=i+1
prev.radd=newnode
newnode.ladd=prev
newnode.radd=next
next.ladd=newnode
self.count=self.count+1
# Main Menu
mylist=CircularDoubleList()
while(1):
print("------------------Circular Doubly Linked List-----------------")
print("1.Create")
print("2.Display")
print("3.Reverse Display")
print("4.Insert First")
print("5.Insert Last")
print("6.Insert Middle")
print("7.Delete First")
print("8.Delete Last")
print("9.Delete Middle")
print("10.Exit")
print("----------------------------------------------------------------")
choice=int(input("Enter your choice"))
if(choice==1):
mylist.createList()
elif(choice==2):
mylist.displayList()
elif(choice==3):
mylist.reversedisplayList()
elif(choice==4):
mylist.insertFirst()
elif(choice==5):
mylist.insertLast()
elif(choice==6):
mylist.insertMiddle()
elif(choice==7):
mylist.deleteFirst()
elif(choice==8):
mylist.deleteLast()
elif(choice==9):
mylist.deleteMiddle()
else:
break
