Circular Queue using Function in C program

#include<stdio.h> #include<conio.h> #include<windows.h> #define SIZE 5 int display(); int insert(); int deletedata();                 int cqueue[SIZE];                 int front=0;                 int rear=0;                 int data; int main() {int ch;                 while(1)                 {                                 printf("\nCircular Queue Operation \n");                                 printf("1.Insert Data\n2.Delete Data\n3.Display Data\n4.Exit");                                 printf("\nChoose Your option  : ");                                 scanf("%d", &ch);                                 switch(ch)                                 {                                                 case 1:                                                                 system("cls");                                                 insert();                                                 break;                                                 case 2:                                                                 system("cls");                                                 deletedata();                                                 break;                                                 case 3:                                                                 system("cls");                                                 display();                                                 break;                                                 case 4:                                                 exit(0);                                                 break;                                                 default:                                                                 system("cls");                                                 printf("Invalid Option Please press a Valid Option ");                                 }                 }                 getch();                } int insert() {                 if(front==(SIZE-1))                 printf("The Circular Queue is Full");                 else {                 printf("Enter a element tobe inserted ");                 scanf("%d", &data);   rear = (rear + 1) % SIZE;   cqueue[rear] = data; } } int deletedata() {  if (front!=rear)                 {                                 {    front = ((front + 1) % SIZE); data=cqueue[front]; printf("Element is deleted"); }                 }                 else                   printf("\nCircular Queue is empty"); } int display() {                 int i,j; if(rear==front) printf("Circular Queue is Empty"); else printf("Elements in circular queue are:\t"); { for (i = front+1; i < rear; i =(i + 1)%SIZE) printf("%d ", cqueue[i]); printf("%d ", cqueue[i]); } }