Array Deletion at Middle Index in DSA Python - Practice Problems & Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output after deleting middle element from an odd-length array

What is the output of the following code after deleting the middle element from the array?

DSA Python

arr = [10, 20, 30, 40, 50]
mid = len(arr) // 2
arr.pop(mid)
print(arr)

A [10, 30, 40, 50]

B [10, 20, 30, 40]

C [20, 30, 40, 50]

D [10, 20, 40, 50]

💡 Hint

Remember that integer division // gives the middle index for odd-length arrays.

The middle index for the array of length 5 is 2 (0-based). Removing element at index 2 removes 30, so the array becomes [10, 20, 40, 50].

❓ Predict Output

intermediate

Output after deleting middle element from an even-length array

What is the output of the following code after deleting the middle element from the array?

DSA Python

arr = [5, 15, 25, 35, 45, 55]
mid = len(arr) // 2
arr.pop(mid)
print(arr)

A [5, 15, 25, 45, 55]

B [15, 25, 35, 45, 55]

C [5, 15, 25, 35, 45]

D [5, 15, 35, 45, 55]

💡 Hint

For even length, integer division picks the higher middle index.

The length is 6, so mid = 3. Removing element at index 3 removes 35, so the array becomes [5, 15, 25, 45, 55].

🔧 Debug

advanced

Identify the error in deleting middle element

What error will this code produce when trying to delete the middle element?

DSA Python

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

A IndexError: pop index out of range

B SyntaxError: invalid syntax

C TypeError: 'float' object cannot be interpreted as an integer

D No error, output: [1, 2, 4]

💡 Hint

Check the type of mid and what pop expects as index.

len(arr) / 2 returns a float (2.0). pop() requires an integer index, so passing a float causes a TypeError.

🧠 Conceptual

advanced

Effect of deleting middle element on array length

If an array has 7 elements, what will be its length after deleting the middle element?

A 7

B 6

C 5

D 8

💡 Hint

Deleting one element reduces length by one.

Deleting one element from 7 elements leaves 6 elements.

❓ Predict Output

expert

Output after deleting middle element in a loop

What is the final output of the code after deleting the middle element repeatedly until the array is empty?

DSA Python

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

A []

B [3]

C [2]

D [1]

💡 Hint

Each loop removes the middle element until no elements remain.

The loop removes the middle element repeatedly until the array is empty, so the final output is an empty list [].