编译原理中的词法分析器，用flex实现，非常适合学习编译原理的大家，程序容易懂，并带有实验报告，希望大家喜欢。-Build on the principle of lexical analyzer, using flex to achieve, very suitable for learning compiler theory of all, the program easier to understand, and with the experimental report, hope you

Flex example. Count number of words, phrases, differents words, words average per phrases and lexical density.

flex词法分析器实现从文件中读入字符串并统计出现次数，写入到另一个文件中-flex lexical analyzer to read from a file into a string and statistical occurrences, written to another file-