Data Structures (Queue operations using arrays)

#include<stdio.h>
#include<conio.h>

int queue[10];
int front = -1;
int rear = -1;
int n = 9;

void queue_insert(int data)
{
     if(front==n)
    {
         printf("Queue rull");
    }
    else if(front==-1)
    {
         queue[0] = data;
         front = rear = 0;
     }
     else
     {
         queue[++rear] = data;
    }
}

void queue_delete()
{
     if(front==-1 && rear==-1)
     {
         printf("Queue empty");
         exit(0);
     }
     else if(front==rear)
     {
          printf("\n%d deleted from the queue.\n",queue[front]);
         front=rear=-1;
     }
     else
     {
     printf("%d deleted from the queue.\n",queue[front]);
     front++;
     }
}

int main()
{
    queue_insert(10);
    queue_insert(20);
    queue_delete();
    getch();
}