Circular Queues

 

The operations are performed based on FIFO (First In First Out) principle. It is also called ‘Ring Buffer’. 

In a normal Queue, we can insert elements until queue becomes full. But once queue becomes full, we can not insert the next element even if there is a space in front of queue.

Operations on Circular Queue:

• Front: Get the front item from the queue.
• Rear: Get the last item from the queue.
• enQueue(value) This function is used to insert an element into the circular queue. In a circular queue, the new element is always inserted at the rear position. 
  • Check whether the queue is full – [i.e., the rear end is in just before the front end in a circular manner].
  • If it is full then display Queue is full. 
    • If the queue is not full then,  insert an element at the end of the queue.
• deQueue() This function is used to delete an element from the circular queue. In a circular queue, the element is always deleted from the front position. 
  • Check whether the queue is Empty.
  • If it is empty then display Queue is empty.
    • If the queue is not empty, then get the last element and remove it from the queue.