Instructions

Solution

//--https://www.codewars.com/kata/55de8eabd9bef5205e0000ba/train/javaimport java.util.*;class Emirps{    private static long reverse(long n){        StringBuilder sb = new StringBuilder(String.valueOf(n));        return Long.valueOf(sb.reverse().toString());    }      private static Boolean isPrime(long n)  {        long i;        Boolean rslt = true;        for(i = 2; i <= Math.sqrt(n); i++){            if(n % i == 0){                rslt = false;                break;            }            }            return rslt;    }            public static long[] findEmirp(long n){        if(n < 13){            return new long[]{0,0,0};        }            List
    
      list = new ArrayList
     
      ();        for(long i = 13; i < n; i++){            if(Emirps.isPrime(i)){                long t = Emirps.reverse(i);                if(i != t && Emirps.isPrime(t)){                    list.add(i);                }                                }            }          long sum = 0;        for(long x : list){            sum += x;        }            return new long[] {list.size(), list.get(list.size() - 1), sum};      }    }
     
    

TDD

import org.junit.Test;import static org.junit.Assert.assertArrayEquals;public class EmirpsTest{    @Test    public void testSomething(){        assertArrayEquals(new long[]{0,0,0}, Emirps.findEmirp(10));        assertArrayEquals(new long[]{4,37,98}, Emirps.findEmirp(50));        assertArrayEquals(new long[]{8,97,418}, Emirps.findEmirp(100));    }    }