Bulls and cows/Player: Difference between revisions
(Go solution) |
|||
Line 720: | Line 720: | ||
1549 -> (0, 0) |
1549 -> (0, 0) |
||
3627 -> (1, 0)</pre> |
3627 -> (1, 0)</pre> |
||
=={{header|Ruby}}== |
|||
{{trans|Python}} |
|||
<lang ruby> |
|||
size = 4 |
|||
scores = [] |
|||
guesses = [] |
|||
puts "Playing Bulls & Cows with #{size} unique digits." |
|||
possible_guesses = ('1'..'9').to_a.permutation(size).to_a.shuffle |
|||
while |
|||
guesses << current_guess = possible_guesses.pop |
|||
print "Guess #{guesses.size} is #{current_guess.join}. Answer (bulls,cows)? " |
|||
scores << score = gets.split(',').map(&:to_i) |
|||
# handle win |
|||
break (puts "Yeah!") if score == [size,0] |
|||
# filter possible guesses |
|||
possible_guesses.select! do |pos_guess| |
|||
bulls = pos_guess.zip(current_guess).count{|digit_pair| digit_pair[0] == digit_pair[1]} |
|||
cows = pos_guess.count{|digit| current_guess.include?( digit )} - bulls |
|||
[bulls, cows] == score |
|||
end |
|||
# handle 'no possible guesses left' |
|||
if possible_guesses.empty? then |
|||
puts "Error in scoring?" |
|||
guesses.zip(scores).each{|gs| puts "#{gs[0].join} => bulls #{gs[1][0]} cows #{gs[1][1]}"} |
|||
break |
|||
end |
|||
end |
|||
</lang> |
|||
'''Regular output''' |
|||
<pre> |
|||
Playing Bulls & Cows with 4 unique digits. |
|||
Guess 1 is 7158. Answer (bulls,cows)? 0,1 |
|||
Guess 2 is 6843. Answer (bulls,cows)? 0,2 |
|||
Guess 3 is 1439. Answer (bulls,cows)? 2,1 |
|||
Guess 4 is 3479. Answer (bulls,cows)? 0,2 |
|||
Guess 5 is 1234. Answer (bulls,cows)? 4,0 |
|||
Yeah! |
|||
</pre> |
|||
'''Wrong scoring''' |
|||
<pre> |
|||
Playing Bulls & Cows with 4 unique digits. |
|||
Guess 1 is 2857. Answer (bulls,cows)? 0,0 |
|||
Guess 2 is 6419. Answer (bulls,cows)? 1,0 |
|||
Error in scoring? |
|||
2857 => bulls 0 cows 0 |
|||
6419 => bulls 1 cows 0 |
|||
</pre> |
|||
=={{header|Tcl}}== |
=={{header|Tcl}}== |
Revision as of 23:43, 7 January 2011
You are encouraged to solve this task according to the task description, using any language you may know.
The task is to write a player of the Bulls and Cows game, rather than a scorer. The player should give intermediate answers that respect the scores to previous attempts.
One method is to generate a list of all possible numbers that could be the answer, then to prune the list by keeping only those numbers that would give an equivalent score to how your last guess was scored. Your next guess can be any number from the pruned list.
Either you guess correctly or run out of numbers to guess, which indicates a problem with the scoring.
C.f: Guess the number/With Feedback (Player)
C#
<lang csharp> using System; using System.Collections.Generic; using System.Linq; using System.Text;
namespace BullsAndCows {
class Program { const int ANSWER_SIZE = 4;
static IEnumerable<string> Permutations(int size) { if (size > 0) { foreach (string s in Permutations(size - 1)) foreach (char n in "123456789") if (!s.Contains(n)) yield return s + n; } else yield return ""; }
static IEnumerable<T> Shuffle<T>(IEnumerable<T> source) { Random random = new Random(); List<T> list = source.ToList(); while (list.Count > 0) { int ix = random.Next(list.Count); yield return list[ix]; list.RemoveAt(ix); } }
static bool ReadBullsCows(out int bulls, out int cows) { string[] input = Console.ReadLine().Split(',').ToArray(); bulls = cows = 0; if (input.Length < 2) return false; else return int.TryParse(input[0], out bulls) && int.TryParse(input[1], out cows); }
static void Main(string[] args) { Console.WriteLine("Bulls and Cows"); Console.WriteLine("=============="); Console.WriteLine(); List<string> answers = Shuffle(Permutations(ANSWER_SIZE)).ToList(); while (answers.Count > 1) { string guess = answers[0]; Console.Write("My guess is {0}. How many bulls, cows? ", guess); int bulls, cows; if (!ReadBullsCows(out bulls, out cows)) Console.WriteLine("Sorry, I didn't understand that. Please try again."); else for (int ans = answers.Count - 1; ans >= 0; ans--) { int tb = 0, tc = 0; for (int ix = 0; ix < ANSWER_SIZE; ix++) if (answers[ans][ix] == guess[ix]) tb++; else if (answers[ans].Contains(guess[ix])) tc++; if ((tb != bulls) || (tc != cows)) answers.RemoveAt(ans); } } if (answers.Count == 1) Console.WriteLine("Hooray! The answer is {0}!", answers[0]); else Console.WriteLine("No possible answer fits the scores you gave."); } }
} </lang> Example output:-
Bulls and Cows ============== My guess is 7854. How many bulls, cows? 0,1 My guess is 1539. How many bulls, cows? 1,2 My guess is 2935. How many bulls, cows? 2,1 My guess is 9635. How many bulls, cows? 1,3 Hooray! The answer is 5936!
Fortran
<lang fortran>module Player
implicit none
contains
subroutine Init(candidates)
integer, intent(in out) :: candidates(:) integer :: a, b, c, d, n n = 0
thousands: do a = 1, 9 hundreds: do b = 1, 9 tens: do c = 1, 9 units: do d = 1, 9
if (b == a) cycle hundreds if (c == b .or. c == a) cycle tens if (d == c .or. d == b .or. d == a) cycle units n = n + 1 candidates(n) = a*1000 + b*100 + c*10 + d end do units end do tens end do hundreds end do thousands
end subroutine init
subroutine Evaluate(bulls, cows, guess, candidates)
integer, intent(in) :: bulls, cows, guess integer, intent(in out) :: candidates(:) integer :: b, c, s, i, j character(4) :: n1, n2 write(n1, "(i4)") guess do i = 1, size(candidates) if (candidates(i) == 0) cycle b = 0 c = 0 write(n2, "(i4)") candidates(i) do j = 1, 4 s = index(n1, n2(j:j)) if(s /= 0) then if(s == j) then b = b + 1 else c = c + 1 end if end if end do if(.not.(b == bulls .and. c == cows)) candidates(i) = 0 end do
end subroutine Evaluate
function Nextguess(candidates)
integer :: Nextguess integer, intent(in out) :: candidates(:) integer :: i
nextguess = 0 do i = 1, size(candidates) if(candidates(i) /= 0) then nextguess = candidates(i) candidates(i) = 0 return end if end do
end function end module Player
program Bulls_Cows
use Player implicit none
integer :: bulls, cows, initial, guess integer :: candidates(3024) = 0 real :: rnum
! Fill candidates array with all possible number combinations
call Init(candidates)
! Random initial guess
call random_seed call random_number(rnum) initial = 3024 * rnum + 1 guess = candidates(initial) candidates(initial) = 0 do write(*, "(a, i4)") "My guess is ", guess write(*, "(a)", advance = "no") "Please score number of Bulls and Cows: " read*, bulls, cows write(*,*) if (bulls == 4) then write(*, "(a)") "Solved!" exit end if
! We haven't found the solution yet so evaluate the remaining candidates ! and eliminate those that do not match the previous score given
call Evaluate(bulls, cows, guess, candidates)
! Get the next guess from the candidates that are left
guess = Nextguess(candidates) if(guess == 0) then
! If we get here then no solution is achievable from the scores given or the program is bugged
write(*, "(a)") "Sorry! I can't find a solution. Possible mistake in the scoring" exit end if end do
end program</lang> Output
My guess is 1528 Please score number of Bulls and Cows: 0 1 My guess is 2346 Please score number of Bulls and Cows: 0 1 My guess is 3179 Please score number of Bulls and Cows: 1 2 My guess is 3795 Please score number of Bulls and Cows: 0 2 My guess is 4971 Please score number of Bulls and Cows: 2 2 My guess is 9471 Please score number of Bulls and Cows: 4 0 Solved!
Go
Notes: Strategy per the suggestion in the problem description. Check algorithm lifted from Bulls and cows program. It was nice to have done that one first. Code here uses Go's built in map type as the container for the list of still-possible numbers. The only the map key is used; the value is assigned a dummy of 0. <lang go> package main
import (
"bufio" "fmt" "os" "strconv" "strings"
)
func main() {
fmt.Println(`Cows and bulls/player
You think of four digit number of unique digits in the range 1 to 9. I guess. You score my guess:
A correct digit but not in the correct place is a cow. A correct digit in the correct place is a bull.
You give my score as two numbers separated with a space.`)
// generate possible patterns, store in map m := make(map[string]int) var g func([]byte, int) g = func(digits []byte, fixed int) { if fixed == 4 { m[string(digits[:4])] = 0 return } for i := fixed; i < len(digits); i++ { digits[fixed], digits[i] = digits[i], digits[fixed] g(digits, fixed+1) digits[fixed], digits[i] = digits[i], digits[fixed] } } g([]byte("123456789"), 0)
// guess/score/eliminate loop for in := bufio.NewReader(os.Stdin);; { // pick a value, ie, guess var guess string for guess = range m { m[guess] = 0, false // remove it break }
// get and parse score var c, b uint for ;; fmt.Println("Score guess as two numbers: cows bulls") { fmt.Printf("My guess: %s. Score? (c b) ", guess) score, err := in.ReadString('\n') if err != nil { fmt.Println("\nSo, bye.") return } s2 := strings.Fields(score) if len(s2) == 2 { c, err = strconv.Atoui(s2[0]) if err == nil && c <= 4 { b, err = strconv.Atoui(s2[1]) if err == nil && c+b <= 4 { break } } } }
// check for win if b == 4 { fmt.Println("I did it. :)") return }
// eliminate patterns with non-matching scores for pat := range m { var cows, bulls uint for ig, cg := range guess { switch strings.IndexRune(pat, cg) { case -1: default: // I just think cows should go first cows++ case ig: bulls++ } } if cows != c || bulls != b { m[pat] = 0, false } }
// check for inconsistency if len(m) == 0 { fmt.Println("Oops, check scoring.") return } }
} </lang>
Haskell
<lang haskell>import Data.List import Control.Monad import System.Random (randomRIO) import Data.Char(digitToInt)
combinationsOf 0 _ = [[]] combinationsOf _ [] = [] combinationsOf k (x:xs) = map (x:) (combinationsOf (k-1) xs) ++ combinationsOf k xs
player = do
let ps = concatMap permutations $ combinationsOf 4 ['1'..'9'] play ps where play ps = if null ps then
putStrLn "Unable to find a solution"
else do i <- randomRIO(0,length ps - 1) let p = ps!!i :: String
putStrLn ("My guess is " ++ p) >> putStrLn "How many bulls and cows?" input <- takeInput let bc = input ::[Int] ps' = filter((==sum bc).length. filter id. map (flip elem p)) $ filter((==head bc).length. filter id. zipWith (==) p) ps if length ps' == 1 then putStrLn $ "The answer is " ++ head ps' else play ps'
takeInput = do inp <- getLine let ui = map digitToInt $ take 2 $ filter(`elem` ['0'..'4']) inp if sum ui > 4 || length ui /= 2 then do putStrLn "Wrong input. Try again"
takeInput else return ui</lang> Example: <lang haskell>*Main> player My guess is 4923 How many bulls and cows? 2 2 My guess is 3924 How many bulls and cows? 1 3 My guess is 4329 How many bulls and cows? 1 3 My guess is 4932 How many bulls and cows? 4 0 The answer is 4932</lang>
J
<lang j>require'misc'
poss=:1+~.4{."1 (i.!9)A.i.9 fmt=: ' ' -.~ ":
play=:3 :0
while.1<#poss=.poss do. smoutput'guessing ',fmt guess=.({~ ?@#)poss bc=.+/\_".prompt 'how many bull and cows? ' poss=.poss #~({.bc)=guess+/@:="1 poss poss=.poss #~({:bc)=guess+/@e."1 poss end. if.#poss do. 'the answer is ',fmt,poss else. 'no valid possibilities' end.
)</lang>
For example: <lang j> play guessing 7461 how many bull and cows? 0 1 guessing 3215 how many bull and cows? 0 3 guessing 2357 how many bull and cows? 2 0 guessing 1359 how many bull and cows? 3 0 the answer is 1358</lang>
Perl
<lang perl>#!/usr/bin/perl use warnings; use strict; use v5.10;
- Build a list of all possible solutions. The regular expression weeds
- out numbers containing zeroes or repeated digits. See how Perl
- automatically converts numbers to strings for us, just because we
- use them as if they were strings:
my @candidates = grep {not /0 | (\d) .* \1 /x} 1234 .. 9876;
- Repeatedly prompt for input until the user supplies a reasonable score.
- The regex validates the user's input and then returns two numbers,
- $+{BULLS} and $+{COWS}.
sub read_score($) {
(my $guess) = @_;
for (;;) { say "My guess: $guess (from ", 0+@candidates, " possibilities)"; if (<> =~ / ^ \h* (?<BULLS> \d) \h* (?<COWS> \d) \h* $ /x and $+{BULLS} + $+{COWS} <= 4) { return ($+{BULLS}, $+{COWS}); }
say "Please specify the number of bulls and the number of cows"; }
}
sub score_correct($$$$) {
my ($a, $b, $bulls, $cows) = @_;
# Count the positions at which the digits match: my $exact = () = grep {substr($a, $_, 1) eq substr($b, $_, 1)} 0 .. 3;
# Cross-match all digits in $a against all digits in $b, using a regex # (specifically, a character class) instead of an explicit loop: my $loose = () = $a =~ /[$b]/g;
return $bulls == $exact && $cows == $loose - $exact;
}
do {
# Pick a number, display it, get the score, and discard candidates # that don't match the score: my $guess = @candidates[rand @candidates]; my ($bulls, $cows) = read_score $guess; @candidates = grep {score_correct $_, $guess, $bulls, $cows} @candidates;
} while (@candidates > 1);
say(@candidates?
"Your secret number is @candidates": "I think you made a mistake with your scoring");
</lang>
Sample game: <lang perl>msl@64Lucid:~/perl$ ./bulls-and-cows My guess: 1869 (from 3024 possibilities) 1 0 My guess: 3265 (from 240 possibilities) 0 2 My guess: 7853 (from 66 possibilities) 1 2 My guess: 7539 (from 7 possibilities) 0 3 Your secret number is 1357 msl@64Lucid:~/perl$</lang>
PicoLisp
<lang PicoLisp>(load "@lib/simul.l")
(de bullsAndCows ()
(let Choices (shuffle (mapcan permute (subsets 4 (range 1 9)))) (use (Guess Bulls Cows) (loop (prinl "Guessing " (setq Guess (pop 'Choices))) (prin "How many bulls and cows? ") (setq Bulls (read) Cows (read)) (setq Choices (filter '((C) (let B (cnt = Guess C) (and (= Bulls B) (= Cows (- (length (sect Guess C)) B)) ) ) ) Choices ) ) (NIL Choices "No matching solution") (NIL (cdr Choices) (pack "The answer is " (car Choices))) ) ) ) )</lang>
Output:
: (bullsAndCows) Guessing 4217 How many bulls and cows? 0 2 Guessing 5762 How many bulls and cows? 1 1 Guessing 9372 How many bulls and cows? 0 1 Guessing 7864 How many bulls and cows? 1 2 Guessing 8754 How many bulls and cows? 0 2 -> "The answer is 2468"
PureBasic
<lang PureBasic>#answerSize = 4 Structure history
answer.s bulls.i cows.i
EndStructure
Procedure evaluateGuesses(*answer.history, List remainingGuesses.s())
Protected i, cows, bulls
ForEach remainingGuesses() bulls = 0: cows = 0 For i = 1 To #answerSize If Mid(remainingGuesses(), i, 1) = Mid(*answer\answer, i, 1) bulls + 1 ElseIf FindString(remainingGuesses(), Mid(*answer\answer, i, 1), 1) cows + 1 EndIf Next If bulls <> *answer\bulls Or cows <> *answer\cows DeleteElement(remainingGuesses()) EndIf Next
EndProcedure
Procedure findPermutations(List permutations.s(), elementChar.s, permSize)
Protected i, j, stackDepth, elementCount = Len(elementChar) - 1, working.s = Space(permSize), *working = @working permSize - 1 Dim stack(permSize) ;holds index states Dim elements(elementCount) Dim elementChar.c(elementCount) For i = 0 To elementCount elementChar(i) = PeekC(@elementChar + i * SizeOf(Character)) Next i = 0 Repeat While i <= elementCount If elements(i) = 0 stack(stackDepth) = i If stackDepth = permSize For j = 0 To permSize PokeC(*working + j * SizeOf(Character), elementChar(stack(j))) Next AddElement(permutations()) permutations() = working Else elements(i) = 1 stackDepth + 1 i = 0 Continue ;skip update EndIf EndIf i + 1 Wend stackDepth - 1 If stackDepth < 0 Break EndIf i = stack(stackDepth) + 1 elements(i - 1) = 0 ForEver
EndProcedure
If OpenConsole()
Define guess.s, guessNum, score.s, delimeter.s NewList remainingGuesses.s() NewList answer.history() findPermutations(remainingGuesses(), "123456789", 4) PrintN("Playing Bulls & Cows with " + Str(#answerSize) + " unique digits." + #CRLF$) Repeat If ListSize(remainingGuesses()) = 0 If answer()\bulls = #answerSize And answer()\cows = 0 PrintN(#CRLF$ + "Solved!") Break ;exit Repeat/Forever EndIf PrintN(#CRLF$ + "BadScoring! Nothing fits the scores you gave.") ForEach answer() PrintN(answer()\answer + " -> [" + Str(answer()\bulls) + ", " + Str(answer()\cows) + "]") Next Break ;exit Repeat/Forever Else guessNum + 1 SelectElement(remainingGuesses(), Random(ListSize(remainingGuesses()) - 1)) guess = remainingGuesses() DeleteElement(remainingGuesses()) Print("Guess #" + Str(guessNum) + " is " + guess + ". What does it score (bulls, cows)?") score = Input() If CountString(score, ",") > 0: delimeter = ",": Else: delimeter = " ": EndIf AddElement(answer()) answer()\answer = guess answer()\bulls = Val(StringField(score, 1, delimeter)) answer()\cows = Val(StringField(score, 2, delimeter)) evaluateGuesses(@answer(), remainingGuesses()) EndIf ForEver Print(#CRLF$ + #CRLF$ + "Press ENTER to exit"): Input() CloseConsole()
EndIf</lang> Sample output:
Playing Bulls & Cows with 4 unique digits. Guess #1 is 6273. What does it score (bulls, cows)?0,2 Guess #2 is 7694. What does it score (bulls, cows)?0,2 Guess #3 is 9826. What does it score (bulls, cows)?0,3 Guess #4 is 2569. What does it score (bulls, cows)?2,0 Guess #5 is 2468. What does it score (bulls, cows)?4,0 Solved! Press ENTER to exit
Python
<lang python>from itertools import permutations from random import shuffle
try:
raw_input
except:
raw_input = input
try:
from itertools import izip
except:
izip = zip
digits = '123456789' size = 4
def parse_score(score):
score = score.strip().split(',') return tuple(int(s.strip()) for s in score)
def scorecalc(guess, chosen):
bulls = cows = 0 for g,c in izip(guess, chosen): if g == c: bulls += 1 elif g in chosen: cows += 1 return bulls, cows
choices = list(permutations(digits, size)) shuffle(choices) answers = [] scores = []
print ("Playing Bulls & Cows with %i unique digits\n" % size)
while True:
ans = choices[0] answers.append(ans) #print ("(Narrowed to %i possibilities)" % len(choices)) score = raw_input("Guess %2i is %*s. Answer (Bulls, cows)? " % (len(answers), size, .join(ans))) score = parse_score(score) scores.append(score) #print("Bulls: %i, Cows: %i" % score) found = score == (size, 0) if found: print ("Ye-haw!") break choices = [c for c in choices if scorecalc(c, ans) == score] if not choices: print ("Bad scoring? nothing fits those scores you gave:") print (' ' + '\n '.join("%s -> %s" % (.join(an),sc) for an,sc in izip(answers, scores))) break</lang>
Sample output
Playing Bulls & Cows with 4 unique digits Guess 1 is 1935. Answer (Bulls, cows)? 0,2 Guess 2 is 4169. Answer (Bulls, cows)? 0,3 Guess 3 is 6413. Answer (Bulls, cows)? 1,1 Guess 4 is 9612. Answer (Bulls, cows)? 1,1 Guess 5 is 9481. Answer (Bulls, cows)? 3,0 Guess 6 is 9471. Answer (Bulls, cows)? 4,0 Ye-haw!
Sample bad output
If the scores are inconsistent you get output like:
Playing Bulls & Cows with 4 unique digits Guess 1 is 1549. Answer (Bulls, cows)? 0,0 Guess 2 is 3627. Answer (Bulls, cows)? 1,0 Bad scoring? nothing fits those scores you gave: 1549 -> (0, 0) 3627 -> (1, 0)
Ruby
<lang ruby> size = 4 scores = [] guesses = [] puts "Playing Bulls & Cows with #{size} unique digits." possible_guesses = ('1'..'9').to_a.permutation(size).to_a.shuffle
while
guesses << current_guess = possible_guesses.pop print "Guess #{guesses.size} is #{current_guess.join}. Answer (bulls,cows)? " scores << score = gets.split(',').map(&:to_i)
# handle win break (puts "Yeah!") if score == [size,0] # filter possible guesses possible_guesses.select! do |pos_guess| bulls = pos_guess.zip(current_guess).count{|digit_pair| digit_pair[0] == digit_pair[1]} cows = pos_guess.count{|digit| current_guess.include?( digit )} - bulls [bulls, cows] == score end
# handle 'no possible guesses left' if possible_guesses.empty? then puts "Error in scoring?" guesses.zip(scores).each{|gs| puts "#{gs[0].join} => bulls #{gs[1][0]} cows #{gs[1][1]}"} break end
end </lang> Regular output
Playing Bulls & Cows with 4 unique digits. Guess 1 is 7158. Answer (bulls,cows)? 0,1 Guess 2 is 6843. Answer (bulls,cows)? 0,2 Guess 3 is 1439. Answer (bulls,cows)? 2,1 Guess 4 is 3479. Answer (bulls,cows)? 0,2 Guess 5 is 1234. Answer (bulls,cows)? 4,0 Yeah!
Wrong scoring
Playing Bulls & Cows with 4 unique digits. Guess 1 is 2857. Answer (bulls,cows)? 0,0 Guess 2 is 6419. Answer (bulls,cows)? 1,0 Error in scoring? 2857 => bulls 0 cows 0 6419 => bulls 1 cows 0
Tcl
<lang tcl>package require struct::list package require struct::set
proc scorecalc {guess chosen} {
set bulls 0 set cows 0 foreach g $guess c $chosen {
if {$g eq $c} { incr bulls } elseif {$g in $chosen} { incr cows }
} return [list $bulls $cows]
}
- Allow override on command line
set size [expr {$argc ? int($argv) : 4}]
set choices {} struct::list foreachperm p [split 123456789 ""] {
struct::set include choices [lrange $p 1 $size]
} set answers {} set scores {}
puts "Playing Bulls & Cows with $size unique digits\n" fconfigure stdout -buffering none while 1 {
set ans [lindex $choices [expr {int(rand()*[llength $choices])}]] lappend answers $ans puts -nonewline \
"Guess [llength $answers] is [join $ans {}]. Answer (Bulls, cows)? "
set score [scan [gets stdin] %d,%d] lappend scores $score if {$score eq {$size 0}} {
puts "Ye-haw!" break
} foreach c $choices[set choices {}] {
if {[scorecalc $c $ans] eq $score} { lappend choices $c }
} if {![llength $choices]} {
puts "Bad scoring? nothing fits those scores you gave:" foreach a $answers s $scores { puts " [join $a {}] -> ([lindex $s 0], [lindex $s 1])" } break
}
}</lang> Sample Output
Playing Bulls & Cows with 4 unique digits Guess 1 is 8527. Answer (Bulls, cows)? 0,1 Guess 2 is 5143. Answer (Bulls, cows)? 0,2 Guess 3 is 9456. Answer (Bulls, cows)? 2,0 Guess 4 is 9412. Answer (Bulls, cows)? 2,1 Guess 5 is 9481. Answer (Bulls, cows)? 3,0 Guess 6 is 9471. Answer (Bulls, cows)? 4,0 Ye-haw!
Sample Bad Output
Playing Bulls & Cows with 4 unique digits Guess 1 is 6578. Answer (Bulls, cows)? 0,0 Guess 2 is 3241. Answer (Bulls, cows)? 1,0 Bad scoring? nothing fits those scores you gave: 6578 -> (0, 0) 3241 -> (1, 0)