Double Ended Queue Deque in DSA Python - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create an empty deque using Python's collections module.

DSA Python

from collections import deque

my_deque = deque([1])
print(my_deque)

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

ANone

B[]

C{}

D()

Attempts:

3 left

💡 Hint

Common Mistakes

Passing None which causes error

To create an empty deque, you pass an empty list [] to deque().

2fill in blank

medium

Complete the code to add an element 10 to the right end of the deque.

DSA Python

from collections import deque

my_deque = deque([])
my_deque.[1](10)
print(my_deque)

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

Aappendleft

Bpop

Cpopleft

Dappend

Attempts:

3 left

💡 Hint

Common Mistakes

Using pop or popleft which remove elements

Using appendleft which adds to the left end

Use append to add an element to the right end of the deque.

3fill in blank

hard

Fix the error in the code to remove an element from the left end of the deque.

DSA Python

from collections import deque

my_deque = deque([1, 2, 3])
removed = my_deque.[1]()
print(removed)
print(my_deque)

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

Apopleft

Bremove

Cpop

Ddelete

Attempts:

3 left

💡 Hint

Common Mistakes

Using pop which removes from right end

Using remove which removes by value, not position

Using delete which is not a deque method

Use popleft() to remove and return the element from the left end of the deque.

4fill in blank

hard

Fill both blanks to rotate the deque one step to the right.

DSA Python

from collections import deque

my_deque = deque([1, 2, 3, 4])
my_deque.[1]([2])
print(my_deque)

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

Arotate

Bappend

C1

D-1

Attempts:

3 left

💡 Hint

Common Mistakes

Using append instead of rotate

Using negative number to rotate right

Use rotate(1) to move all elements one step to the right.

5fill in blank

hard

Fill all three blanks to create a deque, add 5 to the left, and remove from the right.

DSA Python

from collections import deque

my_deque = deque([1])
my_deque.[2](5)
removed = my_deque.[3]()
print(removed)
print(my_deque)

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

A[]

Bappendleft

Cpop

D[1, 2, 3]

Attempts:

3 left

💡 Hint

Common Mistakes

Starting with empty deque instead of list

Using append instead of appendleft

Using popleft instead of pop

Start with deque([1, 2, 3]), add 5 to the left with appendleft, then remove from right with pop.