Question

Suppose a circular queue of capacity (n - 1) elements is implemented with an array of n elements. Assume that the insertion and deletion operations are carried out using REAR and FRONT as array indeed variables respectively. Initially, REAR = FRONT = 0. The conditions to detect queue full and queue empty are

• A. full : (FRONT +1) mode n == REAR empty : REAR == FRONT
• B. full : REAR == FRONT
  empty : (REAR + 1) mod n == FRONT
• C. full : (REAR + 1) mod n == FRONT empty : REAR == FRONT
• D. full : (REAR + 1) mod n == FRONT empty : (FRONT + 1) mod n == REAR

Answer 1

The correct option is C full : (REAR + 1) mod n == FRONT empty : REAR == FRONT

So above condition can be specified as:

Full : (Rear + 1) mod n = front
Empty : Rear = front