Linked List vs Array When to Choose Which in DSA Python - Interactive Comparison Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create an array with 5 elements.

DSA Python

arr = [[1]]

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

A1, 2, 3, 4, 5

B[]

Crange(5)

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Using range(5) directly creates a range object, not a list.

Using empty brackets creates an empty list.

The array is created by listing elements separated by commas inside square brackets.

2fill in blank

medium

Complete the code to add a new node with value 10 at the start of a linked list.

DSA Python

new_node = Node(10)
new_node.next = [1]
head = new_node

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

Anew_node

Bhead

CNone

Dhead.next

Attempts:

3 left

💡 Hint

Common Mistakes

Setting new_node.next to None breaks the list.

Using head.next instead of head causes errors.

To insert at the start, new_node.next should point to the current head.

3fill in blank

hard

Fix the error in the code to remove the last element from an array.

DSA Python

arr = [1, 2, 3, 4, 5]
arr.[1]()

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

Apop()

Bremove(5)

Cpop(0)

Ddelete()

Attempts:

3 left

💡 Hint

Common Mistakes

Using remove(5) removes the first occurrence of 5 but is less efficient.

delete() is not a valid list method.

pop() without arguments removes the last element from the list.

4fill in blank

hard

Fill both blanks to traverse a linked list and print each node's value.

DSA Python

current = head
while current [1] None:
    print(current.[2])
    current = current.next

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

Ais not

Bvalue

Cval

D==

Attempts:

3 left

💡 Hint

Common Mistakes

Using '==' instead of 'is not' for None check.

Using 'val' instead of 'value' if the attribute is named 'value'.

We check if current is not None to continue traversal and print the value attribute of the node.

5fill in blank

hard

Fill all three blanks to create a dictionary comprehension that maps each word to its length if length is greater than 3.

DSA Python

{ [1]: [2] for [3] in words if len([3]) > 3 }

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

Aword

Blen(word)

Ditem

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names inconsistently.

Not filtering words by length correctly.

The comprehension maps each word to its length for words longer than 3 characters.