circular array Queue (conceptual)

Question

for circular arrays Queues, is a scenario possible where back < front and size < capacity?

or is that when back< front, size always equals capacity?

Thank You

Answer 1

Yes, back < front and size < capacity is valid state in a circular buffer/queue. Note that size is generally implicit and calculated as (back-front)%capacity . The Wikipedia article on circular buffers has a great description of how circular buffers function: http://en.wikipedia.org/wiki/Circular_buffer