用于c++的json类库，可以替代绝大多数的结构体，存储数据灵活，从此，无需定义N个繁杂的结构体，函数参数用此很方便。(The JSON class library for c++ can replace most of the structures, and store data flexibly. From then on, there is no need to define N complex structures. Function parameters are very conven