/in/hotel-ll.c: In function 'write_room':
/in/hotel-ll.c:59:19: error: format '%s' expects argument of type 'char *', but argument 3 has type 'int' [-Werror=format=]
     fprintf(fp,"[%s]\n",*room_number);
                   ^
/in/hotel-ll.c:62:13: error: implicit declaration of function 'fprint' [-Werror=implicit-function-declaration]
             fprint(fp, "type = dorm\n");
             ^~~~~~
cc1: all warnings being treated as errors