Add solution #209

Author: JoshCrozier

README.md

@@ -186,6 +186,7 @@
 205|[Isomorphic Strings](./0205-isomorphic-strings.js)|Easy|
 206|[Reverse Linked List](./0206-reverse-linked-list.js)|Easy|
 207|[Course Schedule](./0207-course-schedule.js)|Medium|
+209|[Minimum Size Subarray Sum](./0209-minimum-size-subarray-sum.js)|Medium|
 211|[Design Add and Search Words Data Structure](./0211-design-add-and-search-words-data-structure.js)|Medium|
 213|[House Robber II](./0213-house-robber-ii.js)|Medium|
 214|[Shortest Palindrome](./0214-shortest-palindrome.js)|Hard|

solutions/0209-minimum-size-subarray-sum.js

@@ -0,0 +1,29 @@
+/**
+ * 209. Minimum Size Subarray Sum
+ * https://leetcode.com/problems/minimum-size-subarray-sum/
+ * Difficulty: Medium
+ *
+ * Given an array of positive integers nums and a positive integer target, return the
+ * minimal length of a subarray whose sum is greater than or equal to target. If there
+ * is no such subarray, return 0 instead.
+ */
+
+/**
+ * @param {number} target
+ * @param {number[]} nums
+ * @return {number}
+ */
+var minSubArrayLen = function(target, nums) {
+  let result = Infinity;
+
+  for (let right = 0, sum = 0, left = 0; right < nums.length; right++) {
+    sum += nums[right];
+    while (sum >= target) {
+      result = Math.min(result, right - left + 1);
+      sum -= nums[left];
+      left++;
+    }
+  }
+
+  return result === Infinity ? 0 : result;
+};