factor/extra/rosetta-code/bulls-and-cows/bulls-and-cows.factor

91 lines
2.7 KiB
Factor

! Copyright (c) 2012 Anonymous
! See http://factorcode.org/license.txt for BSD license.
USING: accessors assocs combinators fry grouping hashtables
kernel locals math math.parser math.ranges random sequences
strings io ascii ;
IN: rosetta-code.bulls-and-cows
! http://rosettacode.org/wiki/Bulls_and_cows
! This is an old game played with pencil and paper that was
! later implemented on computer.
! The task is for the program to create a four digit random
! number from the digits 1 to 9, without duplication. The program
! should ask for guesses to this number, reject guesses that are
! malformed, then print the score for the guess.
! The score is computed as:
! 1. The player wins if the guess is the same as the randomly
! chosen number, and the program ends.
! 2. A score of one bull is accumulated for each digit in the
! guess that equals the corresponding digit in the randomly
! chosen initial number.
! 3. A score of one cow is accumulated for each digit in the
! guess that also appears in the randomly chosen number, but in
! the wrong position.
TUPLE: score bulls cows ;
: <score> ( -- score ) 0 0 score boa ;
TUPLE: cow ;
: <cow> ( -- cow ) cow new ;
TUPLE: bull ;
: <bull> ( -- bull ) bull new ;
: inc-bulls ( score -- score ) dup bulls>> 1 + >>bulls ;
: inc-cows ( score -- score ) dup cows>> 1 + >>cows ;
: random-nums ( -- seq ) 9 [1,b] 4 sample ;
: add-digits ( seq -- n ) 0 [ swap 10 * + ] reduce number>string ;
: new-number ( -- n narr ) random-nums dup add-digits ;
: narr>nhash ( narr -- nhash ) { 1 2 3 4 } swap zip ;
: num>hash ( n -- hash )
[ digit> ] { } map-as narr>nhash ;
:: cow-or-bull ( n g -- arr )
{
{ [ n first g at n second = ] [ <bull> ] }
{ [ n second g value? ] [ <cow> ] }
[ f ]
} cond ;
: add-to-score ( arr -- score )
<score> [ bull? [ inc-bulls ] [ inc-cows ] if ] reduce ;
: check-win ( score -- ? ) bulls>> 4 = ;
: sum-score ( n g -- score ? )
'[ _ cow-or-bull ] map sift add-to-score dup check-win ;
: print-sum ( score -- str )
dup bulls>> number>string "Bulls: " swap append swap cows>> number>string
" Cows: " swap 3append "\n" append ;
: (validate-readln) ( str -- ? ) dup length 4 = not swap [ letter? ] all? or ;
: validate-readln ( -- str )
readln dup (validate-readln)
[ "Invalid input.\nPlease enter a valid 4 digit number: "
write flush drop validate-readln ]
when ;
: win ( -- ) "\nYou've won! Good job. You're so smart." print flush ;
: main-loop ( x -- )
"Enter a 4 digit number: " write flush validate-readln num>hash swap
[ sum-score swap print-sum print flush ] keep swap not
[ main-loop ] [ drop win ] if ;
: bulls-and-cows-main ( -- ) new-number drop narr>nhash main-loop ;
MAIN: bulls-and-cows-main