HW2: <BUG-FIX> when calc the raw frequancy score
	devide by tokens number instead of  collocations number
HW2: reorganize the functions

Signed-off-by: unknown <zkk12345@gmail.com>
HW2: minor variables minor changes (variables names)

Signed-off-by: unknown <zkk12345@gmail.com>
HW2: minor changes