1390. Four Divisors

Given an integer array nums, return the sum of divisors of the integers in that array that have exactly four divisors. If there is no such integer in the array, return 0.

Example

Example 1:

Input: nums = [21,4,7] Output: 32

Explanation: 21 has 4 divisors: 1, 3, 7, 21 4 has 3 divisors: 1, 2, 4 7 has 2 divisors: 1, 7 The answer is the sum of divisors of 21 only.

Example 2:

Input: nums = [21,21] Output: 64

Example 3:

Input: nums = [1,2,3,4,5] Output: 0

Constraints:

1 <= nums.length <= 104 1 <= nums[i] <= 105

/**
 * @param {number[]} nums
 * @return {number}
 */

const findDivisors = (num) => {
  const divisors = [1, num];
  const upperLimit = Math.sqrt(num);
  if (Number.isInteger(upperLimit)) {
    return [];
    // divisors.push(upperLimit)
  }
  for (let i = 2; i < upperLimit; i++) {
    if (Number.isInteger(num / i)) {
      divisors.push(i);
      divisors.push(num / i);
    }
    if (divisors.length > 4) {
      return [];
    }
  }
  if (divisors.length === 4) {
    return divisors;
  } else {
    return [];
  }
};
var sumFourDivisors = function (nums) {
  const res = [];
  const length = nums.length;
  for (let i = 0; i < length; i++) {
    res.push(findDivisors(nums[i]).reduce((prev, cur) => prev + cur, 0));
  }
  return res.reduce((prev, cur) => prev + cur, 0);
};