Valid Palindrome

Easy

A phrase is a palindrome if, after converting uppercase to lowercase and removing all non-alphanumeric characters, it reads the same forward and backward. Given a string s, return true if it is a palindrome.

Example 1

Input:  s = "A man, a plan, a canal: Panama"
Output: true

Example 2

Input:  s = "race a car"
Output: false

Constraints

• 1 <= s.length <= 2*10^5
• s consists of printable ASCII characters.