想研究透彻正则表达式，必须知道有穷自动机的原理，这个源码可以给你一个很好的示例参考。编译后程序会生成一个可执行文件，运行这个文件出来一个DOS窗口，然后按提示输入正则表达式。-Wish to research thoroughly regular expressions, you must know the finite automata theory, this source can give you a good example for reference. The compiled program generates an executable file, run this file out of a DOS window, and then enter the regular expression and follow the prompts.