Python Linked List: Count the number of items of a given doubly linked list
10. Count Items in Doubly Linked List
Write a Python program to count the number of items of a given doubly linked list.
Sample Solution:
Python Code:
class Node(object):
# Singly linked node
def __init__(self, data=None, next=None, prev=None):
self.data = data
self.next = next
self.prev = prev
class doubly_linked_list(object):
def __init__(self):
self.head = None
self.tail = None
self.count = 0
def append_item(self, data):
# Append an item
new_item = Node(data, None, None)
if self.head is None:
self.head = new_item
self.tail = self.head
else:
new_item.prev = self.tail
self.tail.next = new_item
self.tail = new_item
self.count += 1
items = doubly_linked_list()
items.append_item('PHP')
items.append_item('Python')
items.append_item('C#')
items.append_item('C++')
items.append_item('Java')
items.append_item('SQL')
print("Number of items of the Doubly linked list:",items.count)
Sample Output:
Number of items of the Doubly linked list: 6
Flowchart:
For more Practice: Solve these Related Problems:
- Write a Python program to count the total number of nodes in a doubly linked list by traversing from the head.
- Write a Python script to implement a recursive function that returns the size of a doubly linked list.
- Write a Python program to create a doubly linked list and then verify its size by traversing from both the head and tail.
- Write a Python function to count the nodes in a doubly linked list and print a message if the list is empty.
Python Code Editor:
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