import java.util.Scanner;
public class Tese_A21 {public static void main(String[] args) {Scanner scanner=new Scanner(System.in);System.out.println("请输入一个整数：");int number = scanner.nextInt(); // 要检查的数if (isPrime(number)) {System.out.println(number + " 是一个素数");} else {System.out.println(number + " 不是一个素数.");}}public static boolean isPrime(int number) {if (number <= 1) {return false;}if (number == 2) {return true;}int sqrt = (int) Math.sqrt(number);for (int i = 2; i <= sqrt; i++) {if (number % i == 0) {return false; // 如果能被整除，则不是素数}}return true; // 没有被整除，是素数}
}