add solution: valid-palindrome

Author: yihyun-kim1

valid-palindrome/yihyun-kim1.js

@@ -0,0 +1,10 @@
+/**
+ * @param {string} s
+ * @return {boolean}
+ */
+const isPalindrome = (s) => {
+  const cleaned = s.toLowerCase().replace(/[^a-z0-9]/g, "");
+  const flipped = cleaned.split("").reverse().join("");
+
+  return cleaned === flipped;
+};