问首n素数优化

EN

package main;

import java.util.Scanner;

public class Prime_Generator {
   public static void main(String args[]) {
      int n;
      int status = 1;
      int num = 3;

      Scanner scanner = new Scanner(System.in);
      System.out.print("First n primes: ");

      n = scanner.nextInt();
      if (n >= 1) {
         System.out.print("First "+n+" prime numbers are: \n");
         System.out.println(2);
      }

      for (int i = 2; i <=n;) {
         for (int j = 2; j <= Math.sqrt(num); j++) {
            if (num%j == 0) {
               status = 0;
               break;
            }
         }
         if (status != 0) {
            System.out.println(num);
            i++;
         }
         status = 1;
         num++;
      }         
   }
}