Java Prime编号程序

public class Tester {

   public static void main(String args[]) {

      int i, m = 0, flag = 0;

      int n = 41;// it is the number to be checked

      m = n / 2;

      if (n == 0 || n == 1) {

         System.out.println(n + " not a prime number");

      } else {

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

            if (n % i == 0) {

               System.out.println(n + " not a prime number");

               flag = 1;

               break;

            }

         }

         if (flag == 0) {

            System.out.println(n + " is a prime number");

         }

      }

   }

}