Queue Operations Quiz

What is a dequeue operation?

• Removes and returns the element from the front of the queue

• Removes and returns the element from the rear of the queue.

• Removes the element from the front of the queue.

• Returns the element from the rear of the queue.

A queue is implemented in Python using the built-in list data structure. What Python method is used to implement enqueue() function?

• insert()

• append()

• add()

• delete()

If maxsize is equal to size of the array used in a circular queue (q), complete the pseudocode given for enqueue operation. function enQueue(element){ if q.isFull() print(‘Queue is full’) else rear=...................... q[rear]=newElement}

• rear+1

• (rear+1) MOD maxsize

• (rear-1) MOD maxsize

• (front-1) MOD maxsize

What element does the rear pointer point to?

• ‘a’

• ‘b’

• ‘c’

• ‘d’

What is the value of q? (Based on the following operations performed on a circular queue implemented using an array: q=Queue(4), q.enQueue(10), q.enQueue(20), q.enQueue(30), q.enQueue(40), q.deQueue(), q.enQueue(50))

• [10, 20, 30, 40]

• [10, 20, 30, 50]

• [50, 10, 20, 30]

• [50, 20, 30, 40]

What is q.rear? (Based on the following operations performed on a circular queue implemented using an array: q=Queue(4), q.enQueue(10), q.enQueue(20), q.enQueue(30), q.enQueue(40), q.deQueue(), q.enQueue(50))

• 0

• 1

• 2

• 3

If max size is equal to size of the array used in a circular queue (q), complete the pseudocode given for dequeue operation. function deQueue(){ if q.isEmpty(){ print(‘Queue is empty’) element=null} else{ .................................. .................................. } return element }

• element=q[front] front=(front+1) MOD maxsize

• element=q[rear] rear=(rear-1) MOD maxsize

• element=q[front] front=(front-1) MOD maxsize

• element=q[front+1] front=(front+1) MOD maxsize

Questions 5 and 6 are based on these operations that are performed on a queue. q=Queue() q.enQueue(‘a’) q.enQueue(‘b’) q.deQueue() q.enQueue(‘c’) q.enQueue(‘d’) What element does the front pointer point to?

• ‘a’

• ‘b’

• ‘c’

• ‘d’

In the circular queue, further operations are performed: q.deQueue() q.enQueue(60) What is the value of q now?

• [50, 60, 30, 40]

• [10, 20, 50, 60]

• [60, 50, 30, 40]

• [60, 50, 10, 20]

What is q.front?

• 0

• 1

• 2

• 3