Array Insertion at Middle Index in DSA Python - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to insert the value 99 at the middle index of the list.

DSA Python

arr = [1, 2, 3, 4, 5]
mid = len(arr) // 2
arr.[1](mid, 99)
print(arr)

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

Aappend

Binsert

Cextend

Dremove

Attempts:

3 left

💡 Hint

Common Mistakes

Using append adds the element at the end, not the middle.

Using remove deletes elements instead of adding.

The insert method adds an element at a specific index. Here, it inserts 99 at the middle index.

2fill in blank

medium

Complete the code to find the middle index of the list correctly.

DSA Python

arr = [10, 20, 30, 40, 50, 60]
mid = [1]
print(mid)

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Alen(arr) // 2

Blen(arr) / 2

Clen(arr) % 2

Darr[len(arr)]

Attempts:

3 left

💡 Hint

Common Mistakes

Using regular division returns a float, which is invalid as a list index.

Using modulo operator does not give the middle index.

Using integer division // gives the middle index as an integer.

3fill in blank

hard

Fix the error in the code to insert 77 at the middle index of the list.

DSA Python

numbers = [5, 10, 15, 20]
middle = len(numbers) // 2
numbers.[1](middle, 77)
print(numbers)

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

Aappend

Bextend

Cinsert

Dadd

Attempts:

3 left

💡 Hint

Common Mistakes

Using append adds at the end, not at the middle index.

Using add or extend are invalid for this operation.

The insert method is correct to add an element at a specific index. Other methods do not accept two arguments or do not insert at an index.

4fill in blank

hard

Fill both blanks to create a list of squares for numbers less than 5 and insert 100 at the middle index.

DSA Python

nums = [1, 2, 3, 4, 5, 6]
squares = [x[1]2 for x in nums if x [2] 5]
mid = len(squares) // 2
squares.insert(mid, 100)
print(squares)

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

A**

B>

C<

D+

Attempts:

3 left

💡 Hint

Common Mistakes

Using '+' instead of '**' does addition, not squaring.

Using '>' instead of '<' filters wrong numbers.

Use ** for exponentiation to square numbers, and < to filter numbers less than 5.

5fill in blank

hard

Fill all three blanks to create a dictionary of numbers and their squares for numbers greater than 2, then insert 50 at the middle index of the list.

DSA Python

nums = [1, 2, 3, 4, 5]
squares_dict = {{ [1]: [2] for [1] in nums if [1] [3] 2 }}
nums.insert(len(nums)//2, 50)
print(nums)
print(squares_dict)

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

Ax

Bx**2

C>

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' instead of '>' filters wrong numbers.

Using the wrong variable name causes errors.

Use x as the key, x**2 as the value, and > to filter numbers greater than 2.