定义C语言或其子集的单词并给出编号，根据给定的语言子集构造词法分析器，从输入的源程序中，识别出各个具有独立意义的单词，即基本保留字、标识符、常量、运算符、分隔符五大类。并依次输出各个单词的内部编码及单词符号自身值（遇到错误时可显示“Error”，然后跳过错误部分继续显示），要求输出以文件形式存放的Token串。-Or a subset of the C language definition of the word and gives the number, according to a given subset of the language constructs lexical analyzer, from the input source, identify the meaning of each word independent, that is basically reserved words, identifiers, constants, operators, delimiters five categories. And in turn the output encoding of each word and word symbols of their own internal value (an error is encountered can be displayed " Error" , and then continue to skip the error part of the display), the output stored in document form requires the Token string.