12. Valid Palindrome

Easy

Description

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.

Examples

Input: s = "A man, a plan, a canal: Panama"
Output: true
Explanation: "amanaplanacanalpanama" is a palindrome.
Input: s = "race a car"
Output: false
Explanation: "raceacar" is not a palindrome.

Constraints

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

Tags

Two Pointers
String
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