Intermediate Algorithm Scripting: Sum All Primes
A prime number is a whole number greater than 1 with exactly two divisors: 1 and itself. For example, 2 is a prime number because it is only divisible by 1 and 2. In contrast, 4 is not prime since it is divisible by 1, 2 and 4.
Rewrite sumPrimes so it returns the sum of all prime numbers that are less than or equal to num.
sumPrimes(10) should return a number.
sumPrimes(10) should return 17.
sumPrimes(977) should return 73156.
function* primesGenerator(qualifierFunc) {
const primes = [2];
yield primes[0];
for (let odd = 3; ; odd += 2) {
if (qualifierFunc && !qualifierFunc(odd)) {
return;
}
if (primes.some(n => odd % n === 0)) {
continue;
}
yield odd;
primes.push(odd);
}
}
function sumPrimes(num) {
return Array.from(primesGenerator(n => n <= num)).reduce((a, b) => a + b);
}
console.log(sumPrimes(10));
console.log(sumPrimes(977));
Output:
17 73156
No comments:
Post a Comment