Untitled

// Online C compiler to run C program online
 #include <stdio.h>
#define max 10
int rear = -1, front = -1;
int queue[max];
void insertion(int d)
{
    if (rear == max - 1)
    {
        printf("\n no space is left");
    }
    else if (front == -1 && rear == -1)
    {
        front = 0;
        rear = 0;
    }
    else
    {
        rear = rear + 1;
    }
    queue[rear] = d;
}
void display()
{
    for (int i = front; i <= rear; i++)
    {
        printf("%d ", queue[i]);
    }
}
int deletion()
{
    if (rear == -1 && front == -1)
    {
        printf("\n queue is empty");
    }
    else
    {
        front = front + 1;
    }
}
int main()
{
    int val, option;
    do
    {
        printf("\n     MENU    ");
        printf(" \n 1.insertion");
        printf("\n 2.dislay");
        printf("\n 3.deletion");
        printf("\n enter ur option: ");
        scanf("%d", &option);
        switch (option)
        {
        case 1:
            printf("\n enter the value to be added : ");
            scanf("%d", &val);
            insertion(val);
           display();
            break;
        case 2:
            display();
            break;
        case 3:
            deletion();
            display();
            break;
        }
    } while (option != 4);

    return 0;
}