[프로그래머스] 약수의 개수와 덧셈 js javascript

function solution(left, right) {
    var answer = 0;
    
    for (i = left; i<=right; i++){
        var factors = 0;
        for(j=1; j<=i; j++){
            if(i%j ==0)
                factors++;
        }
        factors%2===0?answer=answer+i : answer=answer-i;
    }
    return answer;
}