Queue vs Stack When to Use Which in DSA Python - Interactive Comparison Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to add an element to the end of a queue using a list.

DSA Python

queue = []
queue.append([1])
print(queue)

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

A'banana'

B'date'

C'cherry'

D'apple'

Attempts:

3 left

💡 Hint

Common Mistakes

Using insert(0, element) instead of append to add to the queue.

Trying to use pop() to add elements.

The append method adds the element to the end of the list, simulating enqueue in a queue.

2fill in blank

medium

Complete the code to remove the first element from a queue using a list.

DSA Python

queue = ['apple', 'banana', 'cherry']
removed = queue.[1](0)
print(removed)
print(queue)

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

Aremove

Bpop

Cdelete

Ddiscard

Attempts:

3 left

💡 Hint

Common Mistakes

Using remove() which removes by value, not index.

Using pop() without an index, which removes the last element.

pop(0) removes and returns the first element, simulating dequeue in a queue.

3fill in blank

hard

Fix the error in the code to add an element to the top of a stack using a list.

DSA Python

stack = ['a', 'b', 'c']
stack.[1]('d')
print(stack)

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

Apush

Binsert

Cappend

Dadd

Attempts:

3 left

💡 Hint

Common Mistakes

Using push() which is not a list method in Python.

Using insert() which adds at a specific position, not necessarily the top.

append() adds an element to the end of the list, which is the top of the stack.

4fill in blank

hard

Fill both blanks to remove the top element from a stack and print it.

DSA Python

stack = ['x', 'y', 'z']
top = stack.[1]()
print(top)
print(stack[[2]])

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

Apop

Bappend

C-1

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using pop(0) which removes the first element, not the top of the stack.

Using append() instead of pop().

pop() removes the last element (top of stack). Using -1 index accesses the last element.

5fill in blank

hard

Fill all three blanks to create a queue using collections.deque, add an element, and remove the first element.

DSA Python

from collections import deque
queue = deque()
queue.[1]('first')
queue.[2]('second')
removed = queue.[3]()
print(removed)
print(list(queue))

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

Aappend

Bappendleft

Cpopleft

Dpop

Attempts:

3 left

💡 Hint

Common Mistakes

Using pop() which removes from the right end, not the front.

Using appendleft() which adds to the front, not the end.

append() adds to the right end of the deque (end of queue). popleft() removes from the left end (front of queue).