comefrom: <awangdev>921. Minimum Add to Make Parentheses Valid_2.java
code: public int minAddToMakeValid(String s) {
          if (s == null || s.length() == 0) {
              return 0;
          }
          int count = 0, openCount = 0;
          for (char c : s.toCharArray()) {
              if (c == '(') openCount++;
              else if (openCount == 0) count++;
              else openCount--;
          }
          return count + openCount;
      }
masked: public int sample_funcname ( String var_0 ) {
    if ( var_0 == null || var_0 . length ( ) == 0 ) {
      return 0 ;
    }
    int var_1 = 0 , var_2 = 0 ;
    for ( char var_3 : var_0 . toCharArray ( ) ) {
      if ( var_3 == '(' ) var_2 ++ ;
      else if ( var_2 == 0 ) var_1 ++ ;
      else var_2 -- ;
    }
    return var_1 + var_2 ;
  }
  