leetcode-patterns-java/LeetCode_Problems/Java/easy/0125. Valid Palindrome.java at main · elchibek5/leetcode-patterns-java · GitHub

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class Solution {
    public boolean isPalindrome(String s) {
        if (s.isEmpty()) return true;

        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;
    }
}