What is a circular queue in C programming?

Can you explain what a circular queue is in C programming?

A circular queue is a linear data structure that follows the FIFO principle but connects the end back to the front, forming a circle.

How do I implement a circular queue in C?

You can implement a circular queue using an array and two pointers, front and rear, to track the start and end of the queue.

Can you show me a sample code for a circular queue?

Sure! Here's a simple implementation:

#include <stdio.h>
#define SIZE 5

int queue[SIZE];
int front = -1, rear = -1;

void enqueue(int value) {
    if ((rear + 1) % SIZE == front) {
        printf("Queue is full\n");
    } else {
        if (front == -1) front = 0;
        rear = (rear + 1) % SIZE;
        queue[rear] = value;
    }
}

int dequeue() {
    if (front == -1) {
        printf("Queue is empty\n");
        return -1;
    } else {
        int value = queue[front];
        if (front == rear) {
            front = rear = -1;
        } else {
            front = (front + 1) % SIZE;
        }
        return value;
    }
}

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

What are the advantages of using a circular queue?

Circular queues are efficient in utilizing space, as they allow for continuous use of the array without needing to shift elements, which is common in linear queues.