%{#include <stdio.h>%}%%[0-9]+(\.[0-9]+)?[eE][-+]?[0-9]+ printf("index: %s\n", yytext);[0-9]+\.[0-9]+ printf("float: %s\n", yytext);[0-9]+ printf("int: %s\n", yytext);. printf("error\n");%%int main() { yylex(); return 0;}%{#include <stdio.h>%}%%[0-9]+\.[0-9]+[eE][-+]?[0-9]+ {printf("指数： %s\n", yytext);}[0-9]+\.[0-9]+ {printf("小数： %s\n", yytext);}[0-9]+ {printf("整数： %s\n", yytext);}. {printf("出错\n");}%%int main() { yylex(); return 0;}