Queue Implementation Using Array in DSA Python - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to initialize the queue size.

DSA Python

queue = [None] * [1]

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

A10

B5

C0

DNone

Attempts:

3 left

💡 Hint

Common Mistakes

Using 0 or None will not create a usable queue array.

The queue is initialized with a fixed size of 10 to hold elements.

2fill in blank

medium

Complete the code to check if the queue is empty.

DSA Python

def is_empty(front):
    return front == [1]

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

A0

Bfront

C-1

DNone

Attempts:

3 left

💡 Hint

Common Mistakes

Checking for 0 or None will not correctly detect empty queue.

The queue is empty when the front index is -1.

3fill in blank

hard

Fix the error in the enqueue function to update rear correctly.

DSA Python

def enqueue(queue, rear, item, max_size):
    if rear == max_size - 1:
        print('Queue is full')
        return rear
    rear = rear [1] 1
    queue[rear] = item
    return rear

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

A-

B*

C/

D+

Attempts:

3 left

💡 Hint

Common Mistakes

Using - will move rear backward causing errors.

To add an item, rear index must increase by 1 using + operator.

4fill in blank

hard

Fill both blanks to correctly dequeue an item and update front.

DSA Python

def dequeue(queue, front, rear):
    if front == [1]:
        print('Queue is empty')
        return front, None
    item = queue[front]
    if front == rear:
        front = [2]
        rear = -1
    else:
        front += 1
    return front, item

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

A-1

B0

Cfront

Drear

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong values for empty queue check or reset.

If front is -1, queue is empty. When last item is dequeued, front resets to 0 and rear to -1.

5fill in blank

hard

Fill all three blanks to implement a function that prints the queue elements.

DSA Python

def print_queue(queue, front, rear):
    if front == [1]:
        print('Queue is empty')
        return
    i = front
    while i != rear:
        print(queue[i], end=' -> ')
        i = i [2] 1
    print(queue[[3]])

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

A-1

B+

Crear

Dfront

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong empty check or wrong index for last element.

Check if front is -1 for empty. Increment i by 1 to traverse. Print last element at rear index.