user
Create a simple version of the board game:   Mastermind.

It must be possible to:

:   * choose the number of colors will be used in the game (2 - 20)
    * choose the color code length (4 - 10)
    * choose the maximum number of guesses the player has (7 - 20)
    * choose whether or not colors may be repeated in the code

The (computer program) game should display all the player guesses and the results of that guess.

Display (just an idea):

:   :   :   :   :   :   | Feature | Graphic Version | Text Version |
                        | --- | --- | --- |
                        | Player guess | Colored circles | Alphabet letters |
                        | Correct color & position | Black circle | X |
                        | Correct color | White circle | O |
                        | None | Gray circle | - |

A text version example:        1.   ADEF   -   XXO- 
  
Translates to:
  
the first guess;
  
the four colors (ADEF);
  
result:

:   :   :   :   two correct colors and spot,
            :   one correct color/wrong spot, one color isn't in the code.

Happy coding!

Related tasks

* Bulls and cows
* Bulls and cows/Player
* Guess the number
* Guess the number/With Feedback
assistant
(formerly Perl 6)

**Works with**: Rakudo version 2017.01

By default, plays classic Mastermind using letters in place of colors. ( 4 chosen from 6, no repeats, 10 guess limit. ) Pass in parameters to modify the game. Enter a string of --length (default 4) letters with or without spaces. Guesses accept lower or upper case.

```
sub MAIN (
    Int :$colors  where 1 < * < 21 = 6,  Int :$length  where 3 < * < 11 = 4,
    Int :$guesses where 7 < * < 21 = 10, Bool :$repeat = False
  ) {
    my @valid = ('A' .. 'T')[^$colors];
    my $puzzle = $repeat ?? @valid.roll($length) !! @valid.pick($length);
    my @guesses;

    my $black = '●';
    my $white = '○';

    loop {
        clearscr();
        say header();
        printf " %{$length * 2}s :: %s\n", @guesses[$_][0], @guesses[$_][1] for ^@guesses;
        say '';
        lose() if @guesses == $guesses;
        my $guess = get-guess();
        next unless $guess.&is-valid;
        my $score = score($puzzle, $guess);
        win() if $score eq ($black xx $length).join: ' ';
        @guesses.push: [$guess, $score];
    }

    sub header {
        my $num = $guesses - @guesses;
        qq:to/END/;
        Valid letter, but wrong position: ○ - Correct letter and position: ●
        Guess the {$length} element sequence containing the letters {@valid}
        Repeats are {$repeat ?? '' !! 'not '}allowed. You have $num guess{ $num == 1 ?? '' !! 'es'} remaining.
        END
    }

    sub score ($puzzle, $guess) {
        my @score;
        for ^$length {
            if $puzzle[$_] eq $guess[$_] {
                @score.push: $black;
            }
            elsif $puzzle[$_] eq any(@$guess) {
                @score.push: $white;
            }
            else {
                @score.push('-');
            }
        }
        @score.sort.reverse.join: ' ';
    }

    sub clearscr { $*KERNEL ~~ /'win32'/ ?? run('cls') !! run('clear') }

    sub get-guess { (uc prompt 'Your guess?: ').comb(/@valid/) }

    sub is-valid (@guess) { so $length == @guess }

    sub win  { say 'You Win! The correct answer is: ', $puzzle; exit }

    sub lose { say 'Too bad, you ran out of guesses. The solution was: ', $puzzle; exit }
}

```

Sample output:

```
Valid letter, but wrong position: ○ - Correct letter and position: ●
Guess the 4 element sequence containing the letters A B C D E F
Repeats are not allowed. You have 5 guesses remaining.

  A B C D :: ○ ○ ○ -
  C A B E :: ● ○ ○ -
  D A E F :: ● ○ - -
  B A E C :: ● ○ ○ -
  D E B C :: ○ ○ ○ ○

Your guess?: cdeb
You Win! The correct answer is: (C D E B)
```