Tetris

说明：  大概在最近两天之内编码完成，但此前一天开始构思。第一天晚上主要完成了方块旋转算法，第二天也就是今天加了消方块的处理算法。但是可能还有一些考虑不周的地方，比如，没有采用定时中断，而是图方便采用了和cpu频率有关的delay（）函数来模拟时间间隔，这是需要改进的地方。(Probably within the last two days to complete coding, but the idea of the day before the beginning. Completed the first night the main box rotation algorithm, the next day that is today' s consumer box added processing algorithms. However, there may be some places where ill-considered, for example, does not use timer interrupt, but rather seek convenience and the cpu frequency of using the delay () function to simulate the time interval, and that needs improvement.)