模拟一个简单的十字路口交通灯（各个只有红绿黄灯，没有转弯灯）。交通灯一共有4 个状态，一是倒计时60 秒，同时亮南北方向绿灯、东西方向红灯；二是倒计时5 秒，同时数码管闪烁显示‘0’，同时亮南北方向红灯、东西方向黄灯；三是倒计时30 秒，东西方向亮红灯、南北方向绿灯；四是倒计时5 秒，数码管闪烁显示‘0’，东西方向亮黄、南北方向红灯。四个状态循环就构成了一个简单的交通灯（未了降低难度，我们设计简化交通灯，与真实情况不太一样）。-Simulate a simple intersection traffic lights (red, green, yellow, only the individual, there is no turning lights). There are four traffic lights state, one countdown 60 seconds, while the green light north-south direction, the direction of the red stuff　the second is the countdown five seconds, while the LED is blinking display　0 , while red light north-south direction, the direction of the yellow stuff lights　three is the countdown 30 seconds, red light east-west direction, the north-south direction of the green　four is the countdown five seconds, the LED flashes　0 , something Directional Brightness yellow, red light north-south direction. Four state cycle constitutes a simple traffic light (unfinished reduce the difficulty, we designed to simplify the traffic lights, and the truth is not the same).