Delete from Beginning of Doubly Linked List in DSA Python - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to update the head pointer after deleting the first node.

DSA Python

def delete_from_beginning(head):
    if head is None:
        return None
    new_head = head.[1]
    if new_head is not None:
        new_head.prev = None
    return new_head

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

Anext

Bprev

Cdata

Dhead

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'prev' instead of 'next' to update the head.

Not updating the head pointer at all.

After deleting the first node, the new head should be the next node in the list, which is accessed by head.next.

2fill in blank

medium

Complete the code to set the previous pointer of the new head to None.

DSA Python

def delete_from_beginning(head):
    if head is None:
        return None
    new_head = head.next
    if new_head is not None:
        new_head.[1] = None
    return new_head

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

Aprev

Bnext

Cdata

Dhead

Attempts:

3 left

💡 Hint

Common Mistakes

Setting the next pointer to None instead of the previous pointer.

Forgetting to update the previous pointer.

The previous pointer of the new head should be set to None because it becomes the first node.

3fill in blank

hard

Fix the error in the code to correctly delete the first node of the doubly linked list.

DSA Python

def delete_from_beginning(head):
    if head is None:
        return None
    temp = head
    head = head.[1]
    if head is not None:
        head.prev = None
    del temp
    return head

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

Ahead

Bnext

Cdata

Dprev

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'prev' instead of 'next' to update the head.

Deleting the wrong node.

The head should be updated to head.next to move to the next node after deletion.

4fill in blank

hard

Fill both blanks to complete the function that deletes the first node and returns the updated head.

DSA Python

def delete_from_beginning(head):
    if head is None:
        return None
    temp = head
    head = head.[1]
    if head is not None:
        head.[2] = None
    del temp
    return head

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

Anext

Bprev

Cdata

Dhead

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping 'next' and 'prev' in the blanks.

Not deleting the old head node.

First, update the head to head.next. Then set the new head's previous pointer to None.

5fill in blank

hard

Fill all three blanks to complete the function that deletes the first node and returns the updated head.

DSA Python

def delete_from_beginning(head):
    if head is None:
        return None
    temp = head
    head = head.[1]
    if head is not None:
        head.[2] = None
    del [3]
    return head

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

Anext

Bprev

Ctemp

Dhead

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting to delete the old head node.

Using wrong variable names in deletion.

Update head to head.next, set head.prev to None, and delete the old head stored in temp.