Enqueue Using Linked List in DSA Python - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a new node with the given value.

DSA Python

new_node = Node([1])

Drag options to blanks, or click blank then click option'

Avalue

Bhead

CNone

Dtail

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'head' or 'tail' instead of the actual value.

Passing None instead of the value.

We create a new node by passing the value to the Node constructor.

2fill in blank

medium

Complete the code to check if the queue is empty before enqueue.

DSA Python

if self.tail is [1]:

Drag options to blanks, or click blank then click option'

Anew_node

Bself.head

CNone

Dhead

Attempts:

3 left

💡 Hint

Common Mistakes

Comparing tail to head instead of None.

Using 'new_node' in the condition.

If tail is None, the queue is empty and we need to set head and tail to the new node.

3fill in blank

hard

Fix the error in linking the new node at the end of the queue.

DSA Python

self.tail.[1] = new_node

Drag options to blanks, or click blank then click option'

Anext

Bhead

Cprev

Dvalue

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'prev' which is for doubly linked lists.

Trying to assign to 'head' or 'value' instead.

The 'next' pointer of the current tail should point to the new node.

4fill in blank

hard

Fill both blanks to update the tail pointer after enqueue.

DSA Python

self.tail = [1]
self.tail.[2] = None

Drag options to blanks, or click blank then click option'

Anew_node

Bnext

Cprev

Dhead

Attempts:

3 left

💡 Hint

Common Mistakes

Setting tail to head instead of new_node.

Using 'prev' instead of 'next' for the pointer.

After adding the new node, tail should point to it, and its next should be None.

5fill in blank

hard

Fill all three blanks to complete the enqueue method using linked list.

DSA Python

def enqueue(self, value):
    new_node = Node([1])
    if self.tail is [2]:
        self.head = new_node
        self.tail = new_node
    else:
        self.tail.[3] = new_node
        self.tail = new_node

Drag options to blanks, or click blank then click option'

Avalue

BNone

Cnext

Dprev

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'prev' instead of 'next' to link nodes.

Not updating tail after adding new node.

Checking tail against head instead of None.

We create a new node with the value, check if tail is None (empty queue), set head and tail to new node if empty, else link new node at tail.next and update tail.