Memory Layout Comparison Array vs Linked List in DSA Python - Interactive Comparison Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create an array with 5 elements initialized to zero.

DSA Python

array = [[1]] * 5
print(array)

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

A1

BNone

C0

D''

Attempts:

3 left

💡 Hint

Common Mistakes

Using None instead of 0

Using a string instead of a number

The array is initialized with zeros using 0. This creates a list of five zeros.

2fill in blank

medium

Complete the code to define a Node class for a linked list with a value and a next pointer.

DSA Python

class Node:
    def __init__(self, value):
        self.value = value
        self.[1] = None

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

Anext

Bpointer

Cprev

Dlink

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'prev' which is for doubly linked lists

Using 'pointer' or 'link' which are not standard attribute names

The next attribute points to the next node in the linked list.

3fill in blank

hard

Fix the error in the code that appends a new node to the end of a linked list.

DSA Python

def append_node(head, value):
    new_node = Node(value)
    current = head
    while current.[1] is not None:
        current = current.next
    current.next = new_node
    return head

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

Anext

Bprev

Cvalue

Dpointer

Attempts:

3 left

💡 Hint

Common Mistakes

Checking 'prev' which is not used here

Checking 'value' which is data, not a pointer

The loop should check current.next to find the last node.

4fill in blank

hard

Fill both blanks to create a dictionary comprehension that maps array indices to their values if the value is even.

DSA Python

{i: arr[i] for i in range(len(arr)) if arr[i] [1] 2 == 0 and i [2] 5}

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

A%

B==

C<

D>

Attempts:

3 left

💡 Hint

Common Mistakes

Using '==' instead of '%' for even check

Using '>' instead of '<' for index filtering

The modulo operator % checks if a number is even. The comparison < filters indices less than 5.

5fill in blank

hard

Fill all three blanks to create a linked list from a list of values and print the values.

DSA Python

head = Node([1])
current = head
for val in values[1:]:
    current.[2] = Node(val)
    current = current.[3]

# Print linked list values
while head is not None:
    print(head.value, end=' -> ')
    head = head.next
print('None')

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

Avalues[0]

Bnext

Dvalue

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'value' instead of 'next' for linking

Using wrong index for first value

The first node is created with values[0]. The next attribute links nodes and moves the current pointer forward.