Array Deletion at End in DSA Python - Practice Problems & Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output after deleting the last element?

Consider the following Python code that deletes the last element from an array. What will be printed?

DSA Python

arr = [10, 20, 30, 40, 50]
arr.pop()
print(arr)

A [10, 20, 30, 40]

B [10, 20, 30, 40, 50]

C [20, 30, 40, 50]

D []

💡 Hint

The pop() method removes the last element from the list.

The pop() method removes the last element (50) from the list, so the remaining list is [10, 20, 30, 40].

❓ Predict Output

intermediate

What happens if we delete the last element from an empty array?

What error will this code produce?

DSA Python

arr = []
arr.pop()
print(arr)

A []

B IndexError: pop from empty list

C None

D TypeError: pop() missing required argument

💡 Hint

You cannot pop from an empty list.

Calling pop() on an empty list raises an IndexError because there is no element to remove.

🔧 Debug

advanced

Why does this code raise an error when deleting the last element?

Find the reason for the error in this code snippet.

DSA Python

arr = [1, 2, 3]
arr.pop(3)
print(arr)

A SyntaxError due to wrong pop syntax

B TypeError because pop() takes no arguments

C IndexError because index 3 is out of range

D No error, output is [1, 2]

💡 Hint

pop(index) removes element at given index; index must be valid.

The list has indices 0,1,2. pop(3) tries to remove element at index 3 which does not exist, causing IndexError.

🧠 Conceptual

advanced

What is the time complexity of deleting the last element from an array?

Consider a dynamic array (like Python list). What is the time complexity of deleting the last element?

A O(1) constant time

B O(n) linear time

C O(log n) logarithmic time

D O(n^2) quadratic time

💡 Hint

Deleting the last element does not require shifting other elements.

Deleting the last element is done in constant time because no elements need to be moved.

❓ Predict Output

expert

What is the final array after multiple deletions at the end?

What will be printed after these operations?

DSA Python

arr = [5, 10, 15, 20, 25]
arr.pop()
arr.pop()
arr.pop()
print(arr)

A [10, 15, 20]

B [5, 10, 15, 20]

C [5, 10, 15]

D [5, 10]

💡 Hint

Each pop() removes one element from the end.

Three pop() calls remove 25, 20, and 15, leaving [5, 10].