修改过的较为简单易懂的代码，encode代码为一个单独的循环编码，可根据需要修改采用，前边几个为一个完整的H、G矩阵生成代码，及校验代码，简单易懂，码长，迭代次数各种参数都可根据需要进行修改。-The modified relatively simple code, the encode code for a single cycle code, can be modified according to the need, in front of a few for a complete H,