Day23.java

/*Palindrome Sentence
 
Given a single string s, the task is to check if it is a palindrome sentence or not.
A palindrome sentence is a sequence of characters, such as word, phrase, or series of symbols that reads the same backward as forward after converting all uppercase letters to lowercase and removing all non-alphanumeric characters (including spaces and punctuation).

Examples:

Input: s = "Too hot to hoot"
Output: true
Explanation: If we remove all non-alphanumeric characters and convert all uppercase letters to lowercase, string s will become "toohottohoot" which is a palindrome.
Input: s = "Abc 012..## 10cbA"
Output: true
Explanation: If we remove all non-alphanumeric characters and convert all uppercase letters to lowercase, string s will become "abc01210cba" which is a palindrome.
Input: s = "ABC $. def01ASDF"
Output: false
Explanation: The processed string becomes "abcdef01asdf", which is not a palindrome.*/
/*class Solution {
    public boolean isPalindrome(String s) {
        int left = 0, right = s.length() - 1;

        while (left < right) {
            while (left < right && !Character.isLetterOrDigit(s.charAt(left))) {
                left++;
            }
            while (left < right && !Character.isLetterOrDigit(s.charAt(right))) {
                right--;
            }

            if (Character.toLowerCase(s.charAt(left)) !=
                Character.toLowerCase(s.charAt(right))) {
                return false;
            }

            left++;
            right--;
        }
        return true;
    }
}
 */
/*⏱️ Complexity

Time Complexity: O(n)

Space Complexity: O(1) (no extra string created) */