Assignment 4: Mastermind

You will write a system in which the computer randomly invents a pattern and then judges your guesses. Your system will include a function try which returns a list of the number of black pegs and the number of white pegs received. In the example session below, the computer has the pattern (yellow red black blue) in mind.

> (try '(red red red red))
(1 0)
> (try '(red yellow yellow yellow))
(0 2)
> (try '(yellow red green green))
(2 0)
> (try '(yellow red blue blue))
(3 0)
> (try '(yellow red blue white))
(2 1)
> (try '(yellow red black blue))
(4 0)

1. Write a function random-color which takes no arguments and returns one of the six sequence colors at random. You will need the random function given in assignment 1.
2. Write a function random-sequence which takes one argument (a number) and returns a list of that many random colors.
3. Write a function find-blacks which takes a guess and a pattern and returns the number of positions where both lists have the same value.
4. Write a function find-whites which takes a guess and a pattern and returns the number of times a color in the guess appears in the pattern. It is easiest to make this function add a white peg even in case of an exact match, and then subtract the number of black pegs in the next function.

   Note that

   (find-whites '(red yellow red blue) '(green red green green))
   

   should return 1, not 2.
5. Write a curried function judge which takes a pattern and returns a function which takes a guess and returns a list of the numbers of black and white pegs. This function must adjust for the fact that, for each exact match, both a black and a white peg are generated, but only the black peg should be shown.
6. (define try (judge (random-sequence 4)))