Tuenti Challenge 2001 #3

What is the sum of all emirps up to X?

by Luis Martin

JavaScript

function getEmirps(max) {
    var sieve = [], i, j, primes = [];
    for (i = 2; i <= max; ++i) {
        if (!sieve[i]) {
            primes.push(i);
            for (j = i << 1; j <= max; j += i) {
                sieve[j] = true;
            }
        }
    }
    return primes.filter(num => (num.length!=1) && !isPalindrome(num) && reverseIsPrime(num));
}

function isPalindrome(num){
return num.toString().split("").reverse().join("") == num+""

}

function reverseIsPrime(num) {
	num = Number(num.toString().split("").reverse().join(""))
  for(var i = 2; i < num; i++)
    if(num % i === 0) return false;
  return num !== 1;
}

let input = `100
200`;

let lines = input.split("\n")

lines.forEach((line) => {

	console.log(getEmirps(Number(line)).reduce((tot,el)=>tot+=el,0))


});