//Write a c program to do QUEUE operation using array

#include <stdio.h>
void main() {
 int queue[20], n, front = -1, rear = -1, ch;
 printf("QUEUE OPERATIONS\n\n");
 printf("Enter the size of the queue: ");
 scanf("%d", &n);
 while (1) {
 printf("\nPlease enter your choice of operation:\n");
 printf("1. Enqueue\n2. Dequeue\n3. Display\n4. Exit\n");
 scanf("%d", &ch);
 switch (ch) {
 case 1:
 if (rear == n - 1) {
 printf("Queue Overflow!\n");
 } else {
 if (front == -1) {
 front = 0;
 }
 rear++;
 printf("Enter element to enqueue: ");
 scanf("%d", &queue[rear]);
 printf("Element enqueued successfully.\n");
 }
 break;
 case 2:
 if (front == -1) {
 printf("Queue Underflow!\n");
 } else {
 printf("Dequeued element: %d\n", queue[front]);
 if (front == rear) {
 front = rear = -1;
 } else {
 front++;
 }
 }
 break;
 case 3:
 if (front == -1) {
 printf("Queue is empty.\n");
 } else {
 printf("Elements in the queue:\n");
 for (int i = front; i <= rear; i++) {
 printf("%d\n", queue[i]);
 }
 }
 break;
 case 4:
 printf("Exiting the program.\n");
 return;
 default:
 printf("Invalid choice. Please choose again.\n");
 }
 }
}