Introduction - If you have any usage issues, please Google them yourself
This is the lexical analysis process, lexical analysis of requirements: a simple lexical grammar: < keyword> -> main | int | char | string | while | do | if | else | for < identifier> -> L | < identifier> L | < identifier> D < integer> -> D | < integer> D < operator >->+|-|*|/|=|< |> |< =|> =|< > |= = < sector Fu> -> (|) | [|] | (|) the specific contents of the report