Add solution #414

Author: JoshCrozier

README.md

@@ -121,6 +121,7 @@
 374|[Guess Number Higher or Lower](./0374-guess-number-higher-or-lower.js)|Medium|
 383|[Ransom Note](./0383-ransom-note.js)|Easy|
 387|[First Unique Character in a String](./0387-first-unique-character-in-a-string.js)|Easy|
+414|[Third Maximum Number](./0414-third-maximum-number.js)|Easy|
 442|[Find All Duplicates in an Array](./0442-find-all-duplicates-in-an-array.js)|Medium|
 448|[Find All Numbers Disappeared in an Array](./0448-find-all-numbers-disappeared-in-an-array.js)|Easy|
 451|[Sort Characters By Frequency](./0451-sort-characters-by-frequency.js)|Medium|

solutions/0414-third-maximum-number.js

@@ -0,0 +1,21 @@
+/**
+ * 414. Third Maximum Number
+ * https://leetcode.com/problems/third-maximum-number/
+ * Difficulty: Easy
+ *
+ * Given an integer array nums, return the third distinct maximum number in this array.
+ * If the third maximum does not exist, return the maximum number.
+ */
+
+/**
+ * @param {number[]} nums
+ * @return {number}
+ */
+var thirdMax = function(nums) {
+  const sortedSet = [...new Set(nums)].sort((a, b) => a - b);
+  const thirdMax = sortedSet[sortedSet.length - 3];
+
+  return thirdMax !== undefined
+    ? thirdMax
+    : sortedSet[sortedSet.length - 1];
+};