Intersection Point of Two Linked Lists in DSA Python - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to return the node where two linked lists intersect.

DSA Python

def getIntersectionNode(headA, headB):
    while headA and headB and headA != headB:
        headA = headA.next
        headB = headB.next
    return [1]

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

AheadA.next

BheadA

CheadB

DNone

Attempts:

3 left

💡 Hint

Common Mistakes

Returning headB instead of headA

Returning None prematurely

Returning headA.next which may be None

The function returns the intersection node, which is headA when both pointers meet.

2fill in blank

medium

Complete the code to switch the pointer to the other list when it reaches the end.

DSA Python

def getIntersectionNode(headA, headB):
    a, b = headA, headB
    while a != b:
        a = a.next if a else [1]
        b = b.next if b else headA
    return a

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

ANone

BheadA

CheadB

Da

Attempts:

3 left

💡 Hint

Common Mistakes

Switching to headA instead of headB

Not switching pointer at all

Using None instead of headB

When pointer a reaches the end of list A, it switches to head of list B.

3fill in blank

hard

Fix the error in the loop condition to correctly detect intersection.

DSA Python

def getIntersectionNode(headA, headB):
    a, b = headA, headB
    while [1]:
        a = a.next if a else headB
        b = b.next if b else headA
    return a

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

Aa != b

Ba or b

Ca and b

Da == b

Attempts:

3 left

💡 Hint

Common Mistakes

Using equality in the loop condition

Using logical and/or incorrectly

Infinite loop due to wrong condition

The loop continues while pointers a and b are not equal.

4fill in blank

hard

Fill both blanks to create a loop that moves pointers or switches lists.

DSA Python

def getIntersectionNode(headA, headB):
    a, b = headA, headB
    while a != b:
        a = a[1] if a else [2]
        b = b.next if b else headA
    return a

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

A.next

BheadB

CheadA

DNone

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong attribute instead of .next

Switching to headA instead of headB

Using None instead of list head

Pointer a moves to a.next or switches to headB if it reaches the end.

5fill in blank

hard

Fill all three blanks to create a dictionary comprehension filtering nodes by value.

DSA Python

def filterNodes(nodes):
    return [1]: [2] for node in nodes if node.val [3] 10

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

Anode.val

Bnode

C>

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using node instead of node.val as key

Using wrong comparison operator

Not filtering nodes correctly

The comprehension creates a dictionary with keys as node values and values as nodes, filtering nodes with value greater than 10.