I enjoy participating in math competitions run by Mu Alpha Theta, a mathematics honor society in the United States. At competitions, I take a 30-question multiple choice test. There are five choices per question, labeled A through E.
My score on a test is four points for each correct answer, zero points for a question left blank, and negative one points for each wrong answer.
Write a program that grades a test according to the above scoring system. There should be two components to the input: an answer key followed by responses. Questions left blank are to be inputted as blank spaces. The first input must contain only the letters A-E (or a-e, your choice), and it can be assumed that there is no whitespace in the input. The second input must only contain blank spaces and the letters A-E (or a-e). Inputs not implementing 30-question tests must print
Invalid test as output.
The output should be the grade or
If your program prints the number right, number left blank, and number wrong after the final score as
(aR bB cW), take off 20 bytes.
CABBDCABECDBACDBEAACADDBBBEDDA //answer key CABEDDABDC BACDBBAADE CBBEDDA //responses
73 (20R 3B 7W)
Standard rules apply. Shortest code in bytes wins.