<awangdev>36. Valid Sudoku_1.java
private boolean helper(char c, Set<Character> set) {

        if (!set.contains(c)) set.add(c);
        else if (c != '.') return false;
        return true;
    }
private boolean var_0 ( char var_1 , Set < Character > var_4 ) {
  if ( ! var_4 . contains ( var_1 ) ) var_4 . add ( var_1 ) ;
  else if ( var_1 != '.' ) return false ;
  return true ;
}
