[LeetCode] 507. Perfect Number

Perfect number. Meaning of the questions is to give a positive integer number N, and asked if this number is a perfect number. Perfect number N is defined as N may be all greater than zero and the divisor is added. example

Input: 28
Output: True
Explanation: 28 = 1 + 2 + 4 + 7 + 14

Because it involves the divisor, so we will not need to traverse the range of greater than sqrt (N).

 1 /**
 2  * @param {number} num
 3  * @return {boolean}
 4  */
 5 var checkPerfectNumber = function(num) {
 6     // corner case
 7     if (num === 1) {
 8         return false;
 9     }
10 
11     // normal case
12     let res = 1;
13     for (let i = 2; i <= Math.sqrt(num); i++) {
14         if (num % i === 0) {
15             a + = i + Math.floor (whether he / l);
16          }
 17      }
 18      return business === num;
19 };