comefrom: <awangdev>125. Valid Palindrome_2.java
code: public boolean isPalindrome(String s) {
          if (s == null || s.length() <= 1) {
              return true;
          }
          String str = s.replaceAll("[^a-zA-Z0-9]", "").toLowerCase();
          int start = 0;
          int end = str.length() - 1;
          while (start < end) {
              if (str.charAt(start) != str.charAt(end)) {
                  return false;
              }
              start++;
              end--;
          }
          return true;
      }
masked: public boolean var_0 ( String var_2 ) {
    if ( var_2 == null || var_2 . length ( ) <= 1 ) {
      return true ;
    }
    String var_10 = var_2 . replaceAll ( "[^a-zA-Z0-9]" , "" ) . toLowerCase ( ) ;
    int var_12 = 0 ;
    int var_13 = var_10 . length ( ) - 1 ;
    while ( var_12 < var_13 ) {
      if ( var_10 . charAt ( var_12 ) != var_10 . charAt ( var_13 ) ) {
        return false ;
      }
      var_12 ++ ;
      var_13 -- ;
    }
    return true ;
  }
  