feat: implement isPalindrome function with detailed comments on approach and complexity

Author: hongseoupyun

valid-palindrome/hongseoupyun.ts

@@ -0,0 +1,17 @@
+// # Palindrome is a word, phrase, number, or other sequences of characters that reads the same forward and backward (ignoring non-alphanumeric characters - letters and number).
+// # the solution should first filter out non-alphanumeric characters and convert the string to lowercase.
+// # Then, it should check if the cleaned string is equal to its reverse.
+
+
+// Time complexity = O(n), as it checks, replaces, converts to lowercase, and reverses all characters in the string
+// Space complexity = O(n), as it creates a new string with a maximum length equal to the original string
+function isPalindrome(s: string): boolean {
+    let filteredString: string = s.replace(/[^a-zA-Z0-9]/g, '').toLowerCase();
+    let reversed: string = filteredString.split("").reverse().join("")
+
+    if (filteredString === reversed) {
+        return true
+    } else {
+        return false
+    }
+};