说明：  本程序主要实现了一个基于单片机的篮球计时器算法，该篮球计时器能够实现甲乙比分加减，中场比分交换等功能。
(This procedure is mainly based on the realization of a single chip microcomputer basketball timer algorithm, the basketball timer can realize the B score score functions such as addition and subtraction, midfielder exchange. )