CIRCULAR QUEUES
In this blog post will study why to use circular queue, solution to the problem faced by an ordinary queue, operations and C++ code file for implementation of circular queue.
Need of circular queues?
Consider a situation in oridinary queue where the queue is full and you start deleting some items(not completely). Now if you want to insert new items then you get an error saying queue is full.
But why? It's because we check that if rear index is equal to one less than the size of the queue then it's a queue full condition. Even though there are rooms at the front which can be alotted for more data, due to this one condition there will be wastage of memory.
How to overcome this problem?
Shift the elements. As and when the dequeue operation is performed, we can shift the elements towards front such that there will be rooms empty at the rear index which can be used to fill. But shifting operation is expensive and it's a worst case operation in this solution.
There is an easiar way for implementing the queue that is to change the values of front and rear in dequeue and enqueue operations respectively by incrementing them by one and taking modula with size of the queue(You can clearly understand this in code).
In this way, an ordinary queue becomes a circular one. We can use a count variable to keep track of no. of items in the queue.
Standard Operations
- Enqueue: Insert a new item at the rear end of the queue. Increment the rear value by one and take modula with the size. If there is no place then queue is in overflow state.
- Dequeue: Remove an item from the front end of the queue. Increment the front value by one and take modula with the size. If there are no elements then the queue is in underflow state.
- isEmpty: To check whether queue is empty or not.
- isFull: To check if queue is full or not.
- Display Display the items in the queue.
Code file
Please open this in your pc or with a compatible app in your mobile.
C++ Implementation for CIRCULAR QUEUESThat's it from this blog post. If you liked it then do share this blog with your friends or people who wanna get into programming world. Thank You!