MAIN

import java.util.Scanner;
public class Main {
//==============================QUEUE================================\\
    int maxi = 1000;
    int[] a = new int[maxi];
    int f, r;

    void initialize() {
        f = r = -1;
    }

    void enqueue(int val) {
        if (r == a[maxi] - 1) {
            System.out.println("Queue Overflow!");
        } else if (f == -1 && r == -1) {
            f = r = 1;
            a[r] = val;
        } else {
            r++;
            a[r] = val;
        }
    }

    void dequeue() {
        if (f == -1 && r == -1) {
            System.out.println("Queue is already empty!\n\n");
        } else if (f == r) {
            System.out.println("The dequeued element is: \n" + a[f]);
            f = r = -1;
        } else {
            System.out.println("The dequeued element is: " + a[f]);
            System.out.println("\n\n");
            f++;
        }
    }

    void call() {
        int x;
        if (f == -1 && r == -1) {
            System.out.println("The Queue is empty!\n\n");
            return;
        }
        System.out.println("The Contents of the Queue is: ");
        System.out.println("\n\n");
        for (x = f; x <= r; x++) {
            System.out.println(a[x] + " ");
        }
    }

	public static void main(String[] args) {
	Scanner sc = new Scanner(System.in);
	Main obj = new Main();

	obj.initialize();
                    char qw = 0;
                    int value;
                        System.out.println("\t------------------Queue------------------\n");
                        System.out.println("Select below:\n");
                        System.out.print("[a] - Enqueue\n[b] - Dequeue\n[c] - Exit\n");
                        System.out.print("Select your choice: ");
                        qw = sc.nextLine().charAt(0);

                switch (qw) {
                    case 'a':
                        System.out.print("Enter the element to be enqueued: ");
                        value = sc.nextInt();
                        sc.nextLine();
                        obj.enqueue(value);
                        break;
                    case 'b':
                        obj.dequeue();
                        break;
                    case 'c':
                        obj.call();
                        break;
                    default:
                        break;
                }
	}
}