Add solution #896

Author: JoshCrozier

README.md

@@ -706,6 +706,7 @@
 893|[Groups of Special-Equivalent Strings](./0893-groups-of-special-equivalent-strings.js)|Medium|
 894|[All Possible Full Binary Trees](./0894-all-possible-full-binary-trees.js)|Medium|
 895|[Maximum Frequency Stack](./0895-maximum-frequency-stack.js)|Hard|
+896|[Monotonic Array](./0896-monotonic-array.js)|Easy|
 901|[Online Stock Span](./0901-online-stock-span.js)|Medium|
 905|[Sort Array By Parity](./0905-sort-array-by-parity.js)|Easy|
 909|[Snakes and Ladders](./0909-snakes-and-ladders.js)|Medium|

solutions/0896-monotonic-array.js

@@ -0,0 +1,22 @@
+/**
+ * 896. Monotonic Array
+ * https://leetcode.com/problems/monotonic-array/
+ * Difficulty: Easy
+ *
+ * An array is monotonic if it is either monotone increasing or monotone decreasing.
+ *
+ * An array nums is monotone increasing if for all i <= j, nums[i] <= nums[j]. An array nums
+ * is monotone decreasing if for all i <= j, nums[i] >= nums[j].
+ *
+ * Given an integer array nums, return true if the given array is monotonic, or false otherwise.
+ */
+
+/**
+ * @param {number[]} nums
+ * @return {boolean}
+ */
+var isMonotonic = function(nums) {
+  const isIncreasing = nums.every((num, i) => i === 0 || num >= nums[i - 1]);
+  const isDecreasing = nums.every((num, i) => i === 0 || num <= nums[i - 1]);
+  return isIncreasing || isDecreasing;
+};