回文素数的Java实现

//按顺序打印出100个回文素数
public class PrimeNumber {

    public static void main(String[] args) {
        // TODO Auto-generated method stub

        int count = 0;
        for(int i = 2;count < 100;i++){
            if(isPrime(i) && isPalindrome(i)){
                System.out.print(i + " ");
                count++;
                if(count % 10 == 0)
                    System.out.println();
            }
        }
    }
    public static boolean isPrime(int num) { //判断是否为素数
      for(int i = 2;i <= Math.sqrt(num);i++)
          if(num % i == 0)
              return false;
      return true;
  }

    static int reversal(int num) {  //反转原数
      int result = 0;
      while(num != 0){
          int lastDigit = num % 10;
          result = result * 10+ lastDigit;
          num = num / 10;
      }
      return result;
  }

  static boolean isPalindrome(int num) {  //判断是否为回文数
      return num == reversal(num);
  }
}