What is a circular queue in Java and how do I implement it?

What is a circular queue in Java and how do I implement it?

A circular queue is a linear data structure that follows the FIFO principle but connects the end back to the front. To implement it in Java, you can use an array and two pointers to track the front and rear.

Can you show me a simple code example?

Sure! Here's a basic implementation:

class CircularQueue {
    private int[] queue;
    private int front, rear, size;
    private int capacity;

    public CircularQueue(int capacity) {
        this.capacity = capacity;
        queue = new int[capacity];
        front = size = 0;
        rear = capacity - 1;  
    }

    public void enqueue(int item) {
        rear = (rear + 1) % capacity;
        queue[rear] = item;
        size++;
    }

    public int dequeue() {
        int item = queue[front];
        front = (front + 1) % capacity;
        size--;
        return item;
    }
}

This code defines a circular queue with basic enqueue and dequeue operations.

What are the advantages of using a circular queue?

The main advantages of a circular queue are efficient use of space and the ability to reuse empty slots, which prevents wastage of memory. It also allows for continuous data processing without needing to shift elements.

Are there any limitations I should be aware of?

Yes, one limitation is that the circular queue has a fixed size, so if it's full, you can't add more elements until some are removed. Additionally, if not managed properly, it can lead to underflow or overflow conditions.