Check Whether a Number is Prime or Not in C Program programming

 Check Whether a Number is Prime or Not 

#include <stdio.h>

int main()

{

    int n, i, flag = 0;

    printf("Enter a positive integer: ");

    scanf("%d",&n);

    for(i=2; i<=n/2; ++i)

    {

        // condition for nonprime number

        if(n%i==0)

        {

            flag=1;

            break;

        }

    }

    if (flag==0)

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

    else

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

    

    return 0;

}