设计一个简单的词法分析器，从而进一步加深对词法分析器工作原理的理解。了解编译原理中词法分析器的原理，并用一种编程语言的具体代码实现简单的词法分析器的功能（在这里我使用C语言实现，代码可以完成简单的C语言程序中的关键词，变量，分界符，数字，运算符，赋值符。）-Design a simple lexical analyzer to further deepen the understanding of the lexical analyzer works. Compiler theory to understand the principles of lexical analyzer, and using a programming language specific code to achieve a simple lexical analyzer function (here I use the C language, the code can complete a simple C language program in the key words, variables, delimiter, numbers, operators, assignment operator.)