Implementation of queue using array
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#define MAX 100 // Define maximum size of the queue
typedef struct Queue {
int front, rear, size;
int array[MAX];
} Queue;
// Function to initialize the queue
void initQueue(Queue *q) {
q->front = 0;
q->rear = -1;
q->size = 0;
}
// Function to check if the queue is empty
bool isEmpty(Queue *q) {
return q->size == 0;
}
// Function to check if the queue is full
bool isFull(Queue *q) {
return q->size == MAX;
}
// Function to add an element to the queue (enqueue)
void enqueue(Queue *q, int value) {
if (isFull(q)) {
printf("Queue is full. Cannot enqueue %d.\n", value);
return;
}
q->rear = (q->rear + 1) % MAX;
q->array[q->rear] = value;
q->size++;
printf("%d enqueued to queue.\n", value);
}
// Function to remove an element from the queue (dequeue)
int dequeue(Queue *q) {
if (isEmpty(q)) {
printf("Queue is empty. Cannot dequeue.\n");
return -1; // Return a sentinel value to indicate the queue is empty
}
int value = q->array[q->front];
q->front = (q->front + 1) % MAX;
q->size--;
return value;
}
// Function to get the front element of the queue
int front(Queue *q) {
if (isEmpty(q)) {
printf("Queue is empty.\n");
return -1; // Return a sentinel value to indicate the queue is empty
}
return q->array[q->front];
}
// Function to get the rear element of the queue
int rear(Queue *q) {
if (isEmpty(q)) {
printf("Queue is empty.\n");
return -1; // Return a sentinel value to indicate the queue is empty
}
return q->array[q->rear];
}
// Function to print the queue elements
void printQueue(Queue *q) {
if (isEmpty(q)) {
printf("Queue is empty.\n");
return;
}
printf("Queue elements are:\n");
for (int i = 0; i < q->size; i++) {
printf("%d ", q->array[(q->front + i) % MAX]);
}
printf("\n");
}
int main() {
Queue q;
initQueue(&q);
enqueue(&q, 10);
enqueue(&q, 20);
enqueue(&q, 30);
enqueue(&q, 40);
printf("Front element: %d\n", front(&q));
printf("Rear element: %d\n", rear(&q));
printQueue(&q);
printf("%d dequeued from queue.\n", dequeue(&q));
printf("%d dequeued from queue.\n", dequeue(&q));
printQueue(&q);
return 0;
}
