用c++加编译知识实现，一个正规式。而且是用Case语句加循环实现的。能识别一些有限自动机。用c++加编译知识实现，一个正规式。而且是用Case语句加循环实现的。能识别一些有限自动机。-C++ compiler with the increase of knowledge achieved, a formal style. But also increases with the Case statement cycle achievable. Able to identify a number