Add solution #342

Author: JoshCrozier

README.md

@@ -74,6 +74,7 @@
 273|[Integer to English Words](./0273-integer-to-english-words.js)|Hard|
 283|[Move Zeroes](./0283-move-zeroes.js)|Easy|
 326|[Power of Three](./0326-power-of-three.js)|Easy|
+342|[Power of Four](./0342-power-of-four.js)|Easy|
 345|[Reverse Vowels of a String](./0345-reverse-vowels-of-a-string.js)|Easy|
 347|[Top K Frequent Elements](./0347-top-k-frequent-elements.js)|Medium|
 349|[Intersection of Two Arrays](./0349-intersection-of-two-arrays.js)|Easy|

solutions/0342-power-of-four.js

@@ -0,0 +1,22 @@
+/**
+ * 342. Power of Four
+ * https://leetcode.com/problems/power-of-four/
+ * Difficulty: Easy
+ *
+ * Given an integer n, return true if it is a power of four. Otherwise, return false.
+ *
+ * An integer n is a power of four, if there exists an integer x such that n == 4x.
+ */
+
+/**
+ * @param {number} n
+ * @return {boolean}
+ */
+var isPowerOfFour = function(n) {
+  if (n > 1) {
+    while (n % 4 === 0) {
+      n /= 4
+    }
+  }
+  return n === 1;
+};