Add solution #125

Author: JoshCrozier

README.md

@@ -79,6 +79,7 @@
 119|[Pascal's Triangle II](./0119-pascals-triangle-ii.js)|Easy|
 120|[Triangle](./0120-triangle.js)|Medium|
 121|[Best Time to Buy and Sell Stock](./0121-best-time-to-buy-and-sell-stock.js)|Easy|
+125|[Valid Palindrome](./0125-valid-palindrome.js)|Easy|
 128|[Longest Consecutive Sequence](./0128-longest-consecutive-sequence.js)|Medium|
 133|[Clone Graph](./0133-clone-graph.js)|Medium|
 134|[Gas Station](./0134-gas-station.js)|Medium|

solutions/0125-valid-palindrome.js

@@ -0,0 +1,20 @@
+/**
+ * 125. Valid Palindrome
+ * https://leetcode.com/problems/valid-palindrome/
+ * Difficulty: Easy
+ *
+ * A phrase is a palindrome if, after converting all uppercase letters into lowercase letters and
+ * removing all non-alphanumeric characters, it reads the same forward and backward. Alphanumeric
+ * characters include letters and numbers.
+ *
+ * Given a string s, return true if it is a palindrome, or false otherwise.
+ */
+
+/**
+ * @param {string} s
+ * @return {boolean}
+ */
+var isPalindrome = function(s) {
+  const string = s.replace(/[^A-Z\d]+/ig, '').toLowerCase();
+  return string.split('').reverse().join('') === string;
+};