Add solution #643

Author: JoshCrozier

README.md

@@ -218,6 +218,7 @@
 606|[Construct String from Binary Tree](./0606-construct-string-from-binary-tree.js)|Easy|
 617|[Merge Two Binary Trees](./0617-merge-two-binary-trees.js)|Easy|
 628|[Maximum Product of Three Numbers](./0628-maximum-product-of-three-numbers.js)|Easy|
+643|[Maximum Average Subarray I](./0643-maximum-average-subarray-i.js)|Easy|
 645|[Set Mismatch](./0645-set-mismatch.js)|Medium|
 648|[Replace Words](./0648-replace-words.js)|Medium|
 653|[Two Sum IV - Input is a BST](./0653-two-sum-iv-input-is-a-bst.js)|Easy|

solutions/0643-maximum-average-subarray-i.js

@@ -0,0 +1,31 @@
+/**
+ * 643. Maximum Average Subarray I
+ * https://leetcode.com/problems/maximum-average-subarray-i/
+ * Difficulty: Easy
+ *
+ * You are given an integer array nums consisting of n elements, and an integer k.
+ *
+ * Find a contiguous subarray whose length is equal to k that has the maximum average
+ * value and return this value. Any answer with a calculation error less than 10-5
+ * will be accepted.
+ */
+
+/**
+ * @param {number[]} nums
+ * @param {number} k
+ * @return {number}
+ */
+var findMaxAverage = function(nums, k) {
+  let sum = 0;
+  for (let i = 0; i < k; i++) {
+    sum += nums[i];
+  }
+
+  let max = sum;
+  for (let i = k; i < nums.length; i++) {
+    sum = sum - nums[i - k] + nums[i];
+    max = Math.max(max, sum);
+  }
+
+  return max / k;
+};