Clone Linked List with Random Pointer in DSA Python - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a new node with the same value as the current node.

DSA Python

new_node = Node(current.val[1])

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

A[]

B()

C{}

D<>

Attempts:

3 left

💡 Hint

Common Mistakes

Using square brackets [] instead of parentheses.

Using curly braces {} which are for dictionaries or sets.

To create a new node, we call the Node constructor with parentheses and pass the value.

2fill in blank

medium

Complete the code to link the new node after the current node.

DSA Python

current.next = [1]

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Anew_node

Bhead

Ccurrent

Drandom

Attempts:

3 left

💡 Hint

Common Mistakes

Assigning current.next to current itself causes a cycle.

Assigning current.next to head or random is incorrect.

We set current.next to new_node to insert the cloned node after current.

3fill in blank

hard

Fix the error in setting the random pointer of the cloned node.

DSA Python

current.next.random = current.random[1]

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A.next

B.next.random

C.next.next

D.random

Attempts:

3 left

💡 Hint

Common Mistakes

Using .random instead of .next leads to wrong pointer.

Using .next.next skips one node too far.

The cloned node's random pointer should point to the clone of current.random, which is current.random.next.

4fill in blank

hard

Fill both blanks to separate the original and cloned lists.

DSA Python

original.next = original.next[1]
clone.next = clone.next[2]

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A.next

B.random

C.next.next

D.random.next

Attempts:

3 left

💡 Hint

Common Mistakes

Using .random instead of .next causes wrong links.

Using .random.next is incorrect for next pointers.

To separate the lists, we skip every other node by assigning next pointers to next.next.

5fill in blank

hard

Fill all three blanks to complete the clone function.

DSA Python

def cloneLinkedList(head):
    if not head:
        return None
    current = head
    while current:
        new_node = Node(current.val[1])
        new_node.next = current.next
        current.next = new_node
        current = new_node.next
    current = head
    while current:
        if current.random:
            current.next.random = current.random[2]
        current = current.next.next
    original = head
    clone = head.next
    clone_head = clone
    while original:
        original.next = original.next[3]
        if clone.next:
            clone.next = clone.next.next
        original = original.next
        clone = clone.next
    return clone_head

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

A()

B.next

D.next.next

Attempts:

3 left

💡 Hint

Common Mistakes

Missing parentheses in constructor call.

Wrong attribute used for random pointer.

Incorrect next pointer update causing cycles.

The blanks fill the constructor call, the random pointer assignment, and the original list next pointer update.