comefrom: <doocs>0481.Magical String_1.py
code: def magicalString( n: int) -> int:
      s = list('1221121')
      i = 5
      while len(s) < n:
          if s[i] == '1':
              s.append('2' if s[-1] == '1' else '1')
          else:
              s.extend(list('22' if s[-1] == '1' else '11'))
          i += 1
      return s[:n].count('1')
masked: def sample_funcname ( var_0 : int ) -> int :
      var_4 = list ( '1221121' )
      var_6 = 5
      while len ( var_4 ) < var_0 :
          if var_4 [ var_6 ] == '1' :
              var_4.append ( '2' if var_4 [ - 1 ] == '1' else '1' )
          else :
              var_4.extend ( list ( '22' if var_4 [ - 1 ] == '1' else '11' ) )
          var_6 += 1
      return var_4 [ : var_0 ].count ( '1' )
  