remove comentaries problem

%{
    #include <stdio.h>
    #include <stdlib.h>
%}


%%


"/""/"[^\n]*    {}


"/""*"(.|\n)*"*""/" {}



%%

int main(){

  yyin = fopen("file.txt","r");
  yyout = fopen("file.txt","w");
  yylex();
  fclose(yyout);
  fclose(yyin);
  return 0;

}