假设道路交叉口，有红绿黄三色交通控制灯，且要求：

1）。绿灯亮是，车辆可潜行，过30秒，绿灯熄灭，黄灯亮；

2）。黄灯亮5秒后，熄灭，红灯亮，车辆停止前行。红灯亮30秒之后熄灭，黄灯亮；

3）黄灯亮5秒之后，熄灭，绿灯又亮，车辆可通行，如此循环。

-Assuming the road intersection, a red-green-yellow three-color traffic control lights, and requirements: 1). The green light is that vehicles will be allowed to sneak, over 30 seconds, the green light is off, yellow light　2). 5 seconds after the yellow light, off, red light, vehicles to stop before the line. 30 seconds after the red light is off, yellow light　3) 5 seconds after the yellow light, off, green light, bright, vehicles that can use it, and so the cycle.