Add solution #581

Author: JoshCrozier

README.md

@@ -453,6 +453,7 @@
 572|[Subtree of Another Tree](./0572-subtree-of-another-tree.js)|Easy|
 575|[Distribute Candies](./0575-distribute-candies.js)|Easy|
 576|[Out of Boundary Paths](./0576-out-of-boundary-paths.js)|Medium|
+581|[Shortest Unsorted Continuous Subarray](./0581-shortest-unsorted-continuous-subarray.js)|Medium|
 589|[N-ary Tree Preorder Traversal](./0589-n-ary-tree-preorder-traversal.js)|Easy|
 594|[Longest Harmonious Subsequence](./0594-longest-harmonious-subsequence.js)|Easy|
 599|[Minimum Index Sum of Two Lists](./0599-minimum-index-sum-of-two-lists.js)|Easy|

solutions/0581-shortest-unsorted-continuous-subarray.js

@@ -0,0 +1,33 @@
+/**
+ * 581. Shortest Unsorted Continuous Subarray
+ * https://leetcode.com/problems/shortest-unsorted-continuous-subarray/
+ * Difficulty: Medium
+ *
+ * Given an integer array nums, you need to find one continuous subarray such that if you
+ * only sort this subarray in non-decreasing order, then the whole array will be sorted
+ * in non-decreasing order.
+ *
+ * Return the shortest such subarray and output its length.
+ */
+
+/**
+ * @param {number[]} nums
+ * @return {number}
+ */
+var findUnsortedSubarray = function(nums) {
+  let start = -1;
+  let end = -2;
+
+  for (let i = 1, min = nums[nums.length - 1], max = nums[0]; i < nums.length; i++) {
+    max = Math.max(max, nums[i]);
+    min = Math.min(min, nums[nums.length - 1 - i]);
+    if (nums[i] < max) {
+      end = i;
+    }
+    if (nums[nums.length - 1 - i] > min) {
+      start = nums.length - 1 - i;
+    }
+  }
+
+  return end - start + 1;
+};