Add solution #334

Author: JoshCrozier

README.md

@@ -159,6 +159,7 @@
 290|[Word Pattern](./0290-word-pattern.js)|Easy|
 316|[Remove Duplicate Letters](./0316-remove-duplicate-letters.js)|Medium|
 326|[Power of Three](./0326-power-of-three.js)|Easy|
+334|[Increasing Triplet Subsequence](./0334-increasing-triplet-subsequence.js)|Medium|
 342|[Power of Four](./0342-power-of-four.js)|Easy|
 344|[Reverse String](./0344-reverse-string.js)|Easy|
 345|[Reverse Vowels of a String](./0345-reverse-vowels-of-a-string.js)|Easy|

solutions/0334-increasing-triplet-subsequence.js

@@ -0,0 +1,31 @@
+/**
+ * 334. Increasing Triplet Subsequence
+ * https://leetcode.com/problems/increasing-triplet-subsequence/
+ * Difficulty: Medium
+ *
+ * Given an integer array nums, return true if there exists a triple of indices
+ * (i, j, k) such that i < j < k and nums[i] < nums[j] < nums[k]. If no such
+ * indices exists, return false.
+ */
+
+/**
+ * @param {number[]} nums
+ * @return {boolean}
+ */
+var increasingTriplet = function(nums) {
+  let first = Infinity;
+  let second = Infinity;
+
+  for (const current of nums) {
+    if (current > second && current > first) {
+      return true;
+    }
+    if (current > first) {
+      second = current;
+    } else {
+      first = current;
+    }
+  }
+
+  return false;
+};