125. Valid Palindrome

class Solution {
    public boolean isPalindrome(String s) {
        if (s.isEmpty()) {
        	return true;
        }
        int s = 0, e = s.length() - 1;
        char chars, chare;
        while(s <= e) {
        	chars = s.charAt(s);
        	chare = s.charAt(e);
        	if (!Character.isLetterOrDigit(chars)) {
        		s++;
        	} else if(!Character.isLetterOrDigit(chare)) {
        		e--;
        	} else {
        		if (Character.toLowerCase(chars) != Character.toLowerCase(chare)) {
        			return false;
        		}
        		s++;
        		e--;
        	}
        }
        
        return true;
    }

}