C program to find that given number is prime or not using function.

#include<stdio.h>

#include<conio.h>

main(){

int n,x;

int prime( int );

clrscr();

printf("enter a number\n");

scanf("%d",&n);

if (n==1) {

printf("%d is universal prime number\n");

}

else { 

x=prime(n);

if (n==x)

printf("%d is prime number\n",n);

else 

printf("%d is not a prime number\n",n);

}

getch();

return 1;

}

int prime( int y){

int i;

for (i=2;i<y;i++){

if (y%i==0)

return i;

}

return i;

}