how to find number of elements in a Circular Queue

Question

how do i find the number of items in a circular queue?

|front - rear| doesnt always work.

is there one equation to know how many element is in a cir

Answer 1

No of items in Circular queue is,

size = (N-f+r) mod N

where

• N is the size of array used in circular fashion
• f index of the front element
• r index immediately past the rear element

This formula work for both liner and circular queues.