125_Valid Palindrome

class Solution { public boolean isPalindrome(String s) { int len = s.length(); for (int i = 0; i < (len/2); i++) { if (s.charAt(i) != s.charAt(len-1-i)) { return false; } } return true; } }

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