Project Euler > Problem 37 > Truncatable primes (Java Solution)

Problem:

The number 3797 has an interesting property. Being prime itself, it is possible to continuously remove digits from left to right, and remain prime at each stage: 3797, 797, 97, and 7. Similarly we can work from right to left: 3797, 379, 37, and 3.

Find the sum of the only eleven primes that are both truncatable from left to right and right to left.

NOTE: 2, 3, 5, and 7 are not considered to be truncatable primes.

Solution:

748317

Code:
The solution may include methods that will be found here: Library.java .

public interface EulerSolution{

public String run();

}

/* 
 * Solution to Project Euler problem 37
 * By Nayuki Minase
 * 
 * http://nayuki.eigenstate.org/page/project-euler-solutions
 * https://github.com/nayuki/Project-Euler-solutions
 */


public final class p037 implements EulerSolution {
 
 public static void main(String[] args) {
  System.out.println(new p037().run());
 }
 
 
 public String run() {
  long sum = 0;
  for (int count = 0, n = 10; count < 11; n++) {
   if (isTruncatablePrime(n)) {
    sum += n;
    count++;
   }
  }
  return Long.toString(sum);
 }
 
 
 private static boolean isTruncatablePrime(int n) {
  // Test if left-truncatable
  for (long i = 10; i <= n; i *= 10) {
   if (!Library.isPrime(n % (int)i))
    return false;
  }
  
  // Test if right-truncatable
  for (; n != 0; n /= 10) {
   if (!Library.isPrime(n))
    return false;
  }
  
  return true;
 }
 
}