public class panduansushu { public static void main(String args[]) { baiint x, y, j; Scanner i = new Scanner(System.in); System.out.print("请输入du一个数:zhi"); y = i.nextInt(); j = (int) y / 2; for (x = 2; x <= j; x++) { if (y % x == 0) { System.out.println("此数不为素数"); break; } } if (x > j) { System.out.println("此数为素数"); } }}