我们设计一个简单的十字路*通灯。交通灯分东西和南北两个方向，均通过数码管和指示灯指示当前的状态。设两个方向的流量相当，红灯时间45s，绿灯时间40s，黄灯时间5s.-We design a simple traffic light intersection. West and East, and North-South traffic lights both directions, both through the digital control and the indicator indic