Inserting a node at the beginning of a linked list
In the previous exercise, you learned how to implement a Node()
and LinkedList()
class.
In this exercise, you will prepare the code for the insert_at_beginning()
method to add a new node at the beginning of a linked list.
Recall the Node()
class:
class Node:
def __init__(self, data):
self.data = data
self.next = None
This exercise is part of the course
Data Structures and Algorithms in Python
Exercise instructions
- Create the new node.
- Check whether the linked list has a
head
node. - If the linked list has a
head
node, point thenext
node of the new node to thehead
.
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
def insert_at_beginning(self, data):
# Create the new node
new_node = ____(data)
# Check whether the linked list has a head node
if self.____:
# Point the next node of the new node to the head
new_node.___ = self.____
self.head = new_node
else:
self.tail = new_node
self.head = new_node