An emirp (prime spelled backward) is a nonpalindromic prime number whose reversal is also a prime.
For example, 17 is a prime and 71 is a prime, so 17 and 71 are emirps.
We would like to write a program that displays the first 100 emirps.
public class Main { public static void main(String[] args) { int count = 0; for (int i = 10; count < 100; i++) { if (isPrime(i) && isPrime(reverse(i)) && !isPalindrome(i)) { System.out.printf("%10d", i); count++;//from w w w .java 2 s . co m if (count % 10 == 0 && i != 0) System.out.println(); } } } //your code here }
public class Main { public static void main(String[] args) { int count = 0; for (int i = 10; count < 100; i++) { if (isPrime(i) && isPrime(reverse(i)) && !isPalindrome(i)) { System.out.printf("%10d", i); count++; if (count % 10 == 0 && i != 0) System.out.println(); } } } public static boolean isPrime(long n) { if (n < 2) return false; for (int i = 2; i <= n / 2; i++) { if (n % i == 0) return false; } return true; } public static long reverse(long number) { long reverse = 0; while (number != 0) { reverse *= 10; // is ignored first iteration reverse += number % 10; number /= 10; } return reverse; } public static boolean isPalindrome(long number) { return (number == reverse(number)); } }