Insert at Specific Position in Doubly 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 data.

DSA Python

new_node = Node([1])

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

Aitem

Bvalue

Cnode

Ddata

Attempts:

3 left

💡 Hint

Common Mistakes

Using a variable name that is not defined in the function.

Passing the node instead of the data.

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

2fill in blank

medium

Complete the code to check if the position to insert is at the head (position 1).

DSA Python

if position == [1]:

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A1

B-1

C0

DNone

Attempts:

3 left

💡 Hint

Common Mistakes

Checking for position 0 instead of 1.

Using None or negative numbers for position.

Position 1 means inserting at the head of the doubly linked list.

3fill in blank

hard

Fix the error in the loop that moves to the node before the insertion point.

DSA Python

for _ in range([1] - 2):
    current = current.next

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Aposition

Bposition + 1

Cposition - 1

Dposition - 2

Attempts:

3 left

💡 Hint

Common Mistakes

Using position - 1 or position - 2 incorrectly causing off-by-one errors.

Using position + 1 which goes too far.

We loop position - 2 times to reach the node before the insertion point.

4fill in blank

hard

Fill both blanks to correctly insert the new node between nodes.

DSA Python

new_node.next = current.[1]
new_node.prev = current
current.[2] = new_node

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Anext

Bprev

Cnext_node

Dprevious

Attempts:

3 left

💡 Hint

Common Mistakes

Using prev instead of next causing wrong links.

Using incorrect attribute names like next_node.

We set new_node.next to current.next and then current.next to new_node to insert properly.

5fill in blank

hard

Fill all three blanks to update the previous pointer of the next node after insertion.

DSA Python

if new_node.next is not None:
    new_node.next.[1] = new_node

return [2]

# Function ends here

head = [3]

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

Aprev

Bhead

Cnew_node

Dnext

Attempts:

3 left

💡 Hint

Common Mistakes

Not updating the prev pointer of the next node.

Returning or assigning the wrong variable.

We update new_node.next.prev to new_node, return head, and assign head to the function call result.