设计制作一个用于十字路口的交通灯控制器

有一组绿、黄、红灯用于指挥交通，绿灯、黄灯和红灯的持续时间分别为20秒、5秒和25秒；

当有特殊情况（如消防车、救护车等）时，两个方向均为红灯亮，计时停止，当特殊情况结束后，控制器恢复原状态，继续正常运行-design a crossroads for the traffic signal controller is a group in green, yellow and red lights to direct traffic. green, yellow and red, respectively for the duration of 20 seconds, five seconds and 25 seconds; When special circumstances (such as fire engines, ambulances and the like), in both directions were red light, stop time, when the special circumstances after the controller to restore the original state, continue normal operations