Add solution #339

Author: JoshCrozier

README.md

@@ -327,6 +327,7 @@
 336|[Palindrome Pairs](./solutions/0336-palindrome-pairs.js)|Hard|
 337|[House Robber III](./solutions/0337-house-robber-iii.js)|Medium|
 338|[Counting Bits](./solutions/0338-counting-bits.js)|Easy|
+339|[Nested List Weight Sum](./solutions/0339-nested-list-weight-sum.js)|Medium|
 341|[Flatten Nested List Iterator](./solutions/0341-flatten-nested-list-iterator.js)|Medium|
 342|[Power of Four](./solutions/0342-power-of-four.js)|Easy|
 343|[Integer Break](./solutions/0343-integer-break.js)|Medium|

solutions/0339-nested-list-weight-sum.js

@@ -0,0 +1,33 @@
+/**
+ * 339. Nested List Weight Sum
+ * https://leetcode.com/problems/nested-list-weight-sum/
+ * Difficulty: Medium
+ *
+ * You are given a nested list of integers nestedList. Each element is either an integer or
+ * a list whose elements may also be integers or other lists.
+ *
+ * The depth of an integer is the number of lists that it is inside of. For example, the nested
+ * list [1,[2,2],[[3],2],1] has each integer's value set to its depth.
+ *
+ * Return the sum of each integer in nestedList multiplied by its depth.
+ */
+
+/**
+ * @param {NestedInteger[]} nestedList
+ * @return {number}
+ */
+var depthSum = function(nestedList) {
+  return calculateDepth(nestedList, 1);
+
+  function calculateDepth(list, depth) {
+    let total = 0;
+    for (const element of list) {
+      if (element.isInteger()) {
+        total += element.getInteger() * depth;
+      } else {
+        total += calculateDepth(element.getList(), depth + 1);
+      }
+    }
+    return total;
+  }
+};