Test: Queue - 1 - CUET Humanities MCQ

Queue is a data structure which is also called a list where data elements can be added from one end of the list and removed from the other end of the list.

If Front = Rear, then queue has only one element.
Therefore, Front = 0 and Rear = 0

A queue is a linear list in which insertions can take place at one end of the list, which is called rear of the list.

There are two possibilities which occur in dequeue operations on a circular queue.

Priority queue is a kind of queue in which each element is assigned a priority.

This operation on queue removes the front item from the queue.

FIFO stands for First In First Out.

Priority queue does not follow the FIFO method because where insertion process depends on the order of arrival, the deletion process is based on priority.

Minimum stacks needed to implement queue functionality is 2.
It can be done in the following way:
Take two stacks.
For enqueue operation, blindly push the elements into the first stack.
But when it comes to dequeue, we need to use the second stack.
When dequeue operation is to be performed, pop all elements from first stack and push all of them into second stack. Now the element first inserted into the stack will be at the top of the second stack. (FIFO functionality). Pop that element and again pop all elements from second stack and push back to first stack.
Repeat the above process for every dequeue operation.
Hence 2 stacks are enough. This is correct option.

Dequeue supports insertion or deletion of elements from head or back. Dequeue stands for double ended queue.