正则表达式转DFA，设计原理：1正则表达式转换为带ε的NFA（Thompson构造法）；2ε-NFA转为DFA；3最小化DFA；4DFA状态转换表判断是否接受输入字符串，附有详细文档说明。-Regular expressions turn DFA, design principles: a regular expression is converted to ε of the NFA (Thompson Construction Law