queue

#include <stdio.h>
#include <stdlib.h>
#define size 50

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

void enqueue(){
    int item;
    if(rear == size - 1){
        printf("\nOverflow");
    }
    else {
        printf("Enter element to be inserted: ");
        scanf("%d", &item);
        if(front == -1 && rear == -1){
            front = 0;
        }
        queue[++rear] = item;
    }
}

void dequeue(){
    int item = queue[front];

    if(front == -1){
        printf("\nUnderflow");
    }
    else {
        printf("\n%d removed from queue\n", item);
        if(front == rear) {
            rear = -1;
            front = -1;
        }
        else {
            front++;
        }
    }
}

void display() {
    if (front == -1 && rear == -1) {
        printf("\nQueue Underflow\n");
    } else {
        int i;
        printf("\n{");
        for (i = front; i <= rear; i++) {
            printf("%d, ", queue[i]);
        }
        printf("}\n");
    }
}

int main() {
    int arg;
    while (1) {
        printf("\n******************");
        printf("\nEnter your choice:\n1. Enqueue\n2. Dequeue\n3. Display\n0. Exit");
        printf("\n******************\n");
        scanf("%d", &arg);
        switch (arg) {
            case 1: {
                enqueue();
                break;
            }
            case 2: {
                dequeue();
                break;
            }
            case 3: {
                display();
                break;
            }
            case 0: {
                exit(0);
            }
            default: {
                printf("\nInvalid Argument\n");
                break;
            }
        }
    }
}