Add solution #1390

Author: JoshCrozier

README.md

@@ -1,4 +1,4 @@
-# 1,273 LeetCode solutions in JavaScript
+# 1,274 LeetCode solutions in JavaScript
 
 [https://leetcodejavascript.com](https://leetcodejavascript.com)
 
@@ -1060,6 +1060,7 @@
 1387|[Sort Integers by The Power Value](./solutions/1387-sort-integers-by-the-power-value.js)|Medium|
 1388|[Pizza With 3n Slices](./solutions/1388-pizza-with-3n-slices.js)|Hard|
 1389|[Create Target Array in the Given Order](./solutions/1389-create-target-array-in-the-given-order.js)|Easy|
+1390|[Four Divisors](./solutions/1390-four-divisors.js)|Medium|
 1400|[Construct K Palindrome Strings](./solutions/1400-construct-k-palindrome-strings.js)|Medium|
 1402|[Reducing Dishes](./solutions/1402-reducing-dishes.js)|Hard|
 1408|[String Matching in an Array](./solutions/1408-string-matching-in-an-array.js)|Easy|

solutions/1390-four-divisors.js

@@ -0,0 +1,36 @@
+/**
+ * 1390. Four Divisors
+ * https://leetcode.com/problems/four-divisors/
+ * Difficulty: Medium
+ *
+ * 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.
+ */
+
+/**
+ * @param {number[]} nums
+ * @return {number}
+ */
+var sumFourDivisors = function(nums) {
+  function countDivisors(num) {
+    const divisors = new Set();
+    for (let i = 1; i * i <= num; i++) {
+      if (num % i === 0) {
+        divisors.add(i);
+        divisors.add(num / i);
+      }
+    }
+    return divisors;
+  }
+
+  let result = 0;
+  for (const num of nums) {
+    const divisors = countDivisors(num);
+    if (divisors.size === 4) {
+      const sum = [...divisors].reduce((acc, val) => acc + val, 0);
+      result += sum;
+    }
+  }
+
+  return result;
+};