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DLLPrepend.py
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DLLPrepend.py
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from tkinter.messagebox import NO
class Node:
def __init__(self, value):
self.value = value
self.next = None
self.prev = None
class DoublyLinkedList:
def __init__(self, value):
new_node = Node(value)
self.head = new_node
self.tail = new_node
self.length = 1
def print_list(self):
temp = self.head
while temp is not None:
print(temp.value)
temp = temp.next
def append(self, value):
new_node = Node(value)
if self.head is None:
self.head = new_node
self.tail = new_node
else:
self.tail.next = new_node
new_node.prev = self.tail
self.tail = new_node
self.length += 1
return True
def prepend(self, value):
new_node = Node(value)
if self.length == 0:
self.head = new_node
self.tail = new_node
else:
new_node.next = self.head
self.head.prev = new_node
self.head = new_node
self.length += 1
return True
my_dll = DoublyLinkedList(0)
my_dll.append(1)
my_dll.append(2)
my_dll.prepend(3)
my_dll.print_list()