https://metaso.cn/search/8576087031624630272?q=%E8%AF%81%E6%98%8E%E4%BD%BF%E5%BE%97%E6%AD%A4%E5%BC%8F+%24%3D0%24+%E7%9A%84%E6%89%80%E6%9C%89+%24d%24+%E9%83%BD%E6%BB%A1%E8%B6%B3+%24x-d%24+%E6%98%AF%E5%9B%A0%E5%BC%8F%E3%80%82

应该打得开吧