Bulls and cows: Difference between revisions

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(→‎{{header|Julia}}: another version with better input checking)
Line 1,943: Line 1,943:
end
end
end</lang>
end</lang>
The following version checks thoroughly that the input of the player is constituted of four distincts digits.
<lang julia>function bullsandcows ()
bulls = cows = 0
result = (s = {} ; while length(unique(s))<4 push!(s,rand('1':'9')) end; unique(s))
println("A game of bulls and cows!")
while (bulls != 4)
print("Your guess? ")
guess = collect(chomp(readline(STDIN)))
if ! (length(unique(guess)) == length(guess) == 4 && all(isdigit,guess))
println("please, enter four distincts digits")
continue
end
bulls = sum(map(==, guess, result))
cows = length(intersect(guess,result)) - bulls
println("$bulls bulls and $cows cows!")
end
println("You win!")
end</lang>
{{Out}}
<pre>julia> bullsandcows()
A game of bulls and cows!
Your guess? 1234
0 bulls and 2 cows!
Your guess? 12334
please, enter four distincts digits
Your guess? 5678
1 bulls and 1 cows!
Your guess? 1111
please, enter four distincts digits
Your guess? grr
please, enter four distincts digits
Your guess? ...
please, enter four distincts digits
Your guess? </pre>


=={{header|Liberty BASIC}}==
=={{header|Liberty BASIC}}==

Revision as of 22:52, 24 October 2013

Task
Bulls and cows
You are encouraged to solve this task according to the task description, using any language you may know.

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.
Cf,

Ada

<lang Ada>with Ada.Text_IO; use Ada.Text_IO; with Ada.Numerics.Discrete_Random;

procedure Bulls_And_Cows is

  package Random_Natural is new Ada.Numerics.Discrete_Random (Natural);
  Number : String (1..4);

begin

  declare -- Generation of number
     use Random_Natural;
     Digit    : String   := "123456789";
     Size     : Positive := 9;
     Dice     : Generator;
     Position : Natural;
  begin
     Reset (Dice);
     for I in Number'Range loop
        Position := Random (Dice) mod Size + 1;
        Number (I) := Digit (Position);
        Digit (Position..Size - 1) := Digit (Position + 1..Size);
        Size := Size - 1;
     end loop;
  end;
  loop -- Guessing loop
     Put ("Enter four digits:");
     declare
        Guess : String  := Get_Line;
        Bulls : Natural := 0;
        Cows  : Natural := 0;
     begin
        if Guess'Length /= 4 then
           raise Data_Error;
        end if;
        for I in Guess'Range loop
           for J in Number'Range loop                  
              if Guess (I) not in '1'..'9' or else (I < J and then Guess (I) = Guess (J)) then
                 raise Data_Error;
              end if;
              if Number (I) = Guess (J) then
                 if I = J then
                    Bulls := Bulls + 1;
                 else
                    Cows := Cows + 1;
                 end if;
              end if;
           end loop;
        end loop;
        exit when Bulls = 4;
        Put_Line (Integer'Image (Bulls) & " bulls," & Integer'Image (Cows) & " cows");
     exception
        when Data_Error => Put_Line ("You should enter four different digits 1..9");
     end;
  end loop;

end Bulls_And_Cows;</lang>

ALGOL 68

Translation of: Python
Works with: ALGOL 68 version Revision 1 - no extensions to language used
Works with: ALGOL 68G version Any - tested with release 1.18.0-9h.tiny
Works with: ELLA ALGOL 68 version Any (with appropriate job cards) - tested with release 1.8-8d

<lang algol68>STRING digits = "123456789";

[4]CHAR chosen; STRING available := digits; FOR i TO UPB chosen DO

   INT c = ENTIER(random*UPB available)+1; 
   chosen[i] := available[c]; 
   available := available[:c-1]+available[c+1:]

OD;

COMMENT print((chosen, new line)); # Debug # END COMMENT

OP D = (INT d)STRING: whole(d,0); # for formatting an integer #

print (("I have chosen a number from ",D UPB chosen," unique digits from 1 to 9 arranged in a random order.", new line, "You need to input a ",D UPB chosen," digit, unique digit number as a guess at what I have chosen", new line));

PRIO WITHIN = 5, NOTWITHIN = 5; OP WITHIN = (CHAR c, []CHAR s)BOOL: char in string(c,LOC INT,s); OP NOTWITHIN = (CHAR c, []CHAR s)BOOL: NOT ( c WITHIN s );

INT guesses := 0, bulls, cows; WHILE

   STRING guess;
   guesses +:= 1;
   WHILE 
       # get a good guess #
       print((new line,"Next guess [",D guesses,"]: "));
       read((guess, new line));
       IF UPB guess NE UPB chosen THEN
           FALSE
       ELSE
           BOOL ok;
           FOR i TO UPB guess WHILE
               ok := guess[i] WITHIN digits AND guess[i] NOTWITHIN guess[i+1:]
           DO SKIP OD;
           NOT ok 
       FI
   DO
       print(("Problem, try again. You need to enter ",D UPB chosen," unique digits from 1 to 9", new line))
   OD;
  1. WHILE #
   guess NE chosen

DO

   bulls := cows := 0;
   FOR i TO UPB chosen DO
       IF guess[i] = chosen[i] THEN
           bulls +:= 1
       ELIF guess[i] WITHIN chosen THEN
           cows +:= 1
       FI
   OD;
   print(("  ",D bulls," Bulls",new line,"  ",D cows," Cows"))

OD; print((new line, "Congratulations you guessed correctly in ",D guesses," attempts.",new line))</lang> Output:

I have chosen a number from 4 unique digits from 1 to 9 arranged in a random order.
You need to input a 4 digit, unique digit number as a guess at what I have chosen

Next guess [1]: 

AutoHotkey

<lang autohotkey>While StrLen(Code) < 4 {

 Random, num, 1, 9
 If !InStr(Code, num)
   Code .= num

} Gui, Add, Edit, vGuess, Enter a guess... Gui, Add, Button, wp Default, Submit Gui, Add, ListBox, ym r8 vHistory Gui, Show Return

ButtonSubmit:

 Gui, Submit, NoHide
 If StrLen(Guess) != 4
   Return
 If Guess is not digit
   Return
 bulls:=0, cows:=0
 Loop, 4
   If (SubStr(Guess, A_Index, 1) = SubStr(Code, A_Index, 1))
     bulls++
   Else If InStr(Code, SubStr(Guess, A_Index, 1))
     cows++
 GuiControl,, History, % Guess ": " bulls " Bulls " cows " Cows"

Return

GuiClose:

 ExitApp</lang>

BASIC

Works with: QBasic

<lang qbasic>DEFINT A-Z

DIM secret AS STRING DIM guess AS STRING DIM c AS STRING DIM bulls, cows, guesses, i

RANDOMIZE TIMER DO WHILE LEN(secret) < 4

   c = CHR$(INT(RND * 10) + 48)
   IF INSTR(secret, c) = 0 THEN secret = secret + c

LOOP

guesses = 0 DO

   INPUT "Guess a 4-digit number with no duplicate digits: "; guess
   guess = LTRIM$(RTRIM$(guess))
   IF LEN(guess) = 0 THEN EXIT DO
   IF LEN(guess) <> 4 OR VAL(guess) = 0 THEN
       PRINT "** You should enter 4 numeric digits!"
       GOTO looper
   END IF
   bulls = 0: cows = 0: guesses = guesses + 1
   FOR i = 1 TO 4
       c = MID$(secret, i, 1)
       IF MID$(guess, i, 1) = c THEN
           bulls = bulls + 1
       ELSEIF INSTR(guess, c) THEN
           cows = cows + 1
       END IF
   NEXT i
   PRINT bulls; " bulls, "; cows; " cows"
   IF guess = secret THEN
       PRINT "You won after "; guesses; " guesses!"
       EXIT DO
   END IF

looper: LOOP</lang>

BBC BASIC

<lang bbcbasic> secret$ = ""

     REPEAT
       c$ = CHR$(&30 + RND(9))
       IF INSTR(secret$, c$) = 0 secret$ += c$
     UNTIL LEN(secret$) = 4
     
     PRINT "Guess a four-digit number with no digit used twice."'
     guesses% = 0
     REPEAT
       
       REPEAT
         INPUT "Enter your guess: " guess$
         IF LEN(guess$) <> 4 PRINT "Must be a four-digit number"
       UNTIL LEN(guess$) = 4
       guesses% += 1
       
       IF guess$ = secret$ PRINT "You won after "; guesses% " guesses!" : END
       
       bulls% = 0
       cows% = 0
       FOR i% = 1 TO 4
         c$ = MID$(secret$, i%, 1)
         IF MID$(guess$, i%, 1) = c$ THEN
           bulls% += 1
         ELSE IF INSTR(guess$, c$) THEN
             cows% += 1
           ENDIF
         ENDIF
       NEXT i%
       PRINT "You got " ;bulls% " bull(s) and " ;cows% " cow(s)."
       
     UNTIL FALSE

</lang>

Brat

<lang brat>secret_length = 4

secret = [1 2 3 4 5 6 7 8 9].shuffle.pop secret_length

score = { guess |

 cows = 0
 bulls = 0 
 guess.each_with_index { digit, index | 
   true? digit == secret[index]
     { bulls = bulls + 1 }
     { true? secret.include?(digit)
       { cows = cows + 1 }
     }
 } 
 [cows: cows, bulls: bulls]

}

won = false guesses = 1

p "I have chosen a number with four unique digits from 1 through 9. Can you guess it?"

while { not won }

 {
   print "Guess #{guesses}: "
   guess = g.strip.dice.map { d | d.to_i }
   when { guess == secret }  { p "You won in #{guesses} guesses!"; won = true }
     { guess.include?(0) || guess.include?(null) } { p "Your guess should only include digits 1 through 9." }
     { guess.length != secret.length } { p "Your guess was not the correct length. The number has exactly #{secret.length} digits." }
     { guess.unique.length != secret.length } { p "Each digit should only appear once in your guess." }
     { true } {
       result = score guess
       p "Score: #{result[:bulls]} bulls, #{result[:cows]} cows."
       guesses = guesses + 1
     }    
 }</lang>

C

Library: ncurses

<lang c>#include <stdio.h>

  1. include <stdarg.h>
  2. include <stdlib.h>
  3. include <stdbool.h>
  4. include <curses.h>
  5. include <string.h>
  1. define MAX_NUM_TRIES 72
  2. define LINE_BEGIN 7
  3. define LAST_LINE 18

int yp=LINE_BEGIN, xp=0;

char number[5]; char guess[5];

  1. define MAX_STR 256

void mvaddstrf(int y, int x, const char *fmt, ...) {

 va_list args;
 char buf[MAX_STR];
 
 va_start(args, fmt);
 vsprintf(buf, fmt, args);
 move(y, x);
 clrtoeol();
 addstr(buf);
 va_end(args);

}

void ask_for_a_number() {

 int i=0;
 char symbols[] = "123456789";
 move(5,0); clrtoeol();
 addstr("Enter four digits: ");
 while(i<4) {
   int c = getch();
   if ( (c >= '1') && (c <= '9') && (symbols[c-'1']!=0) ) {
     addch(c);
     symbols[c-'1'] = 0;
     guess[i++] = c;
   }
 }

}

void choose_the_number() {

 int i=0, j;
 char symbols[] = "123456789";
 while(i<4) {
   j = rand() % 9;
   if ( symbols[j] != 0 ) {
     number[i++] = symbols[j];
     symbols[j] = 0;
   }
 }

}</lang>

The following function contains the code to check how many bulls and cows there are.

<lang c>bool take_it_or_not() {

 int i;
 int cows=0, bulls=0;
 for(i=0; i < 4; i++) {
   if ( number[i] == guess[i] ) {
     bulls++;
   } else if ( strchr(number, guess[i]) != NULL ) {
     cows++;
   }
 }
 move(yp, xp);
 addstr(guess); addch(' ');
 if ( bulls == 4 ) { yp++; return true; }
 if ( (cows==0) && (bulls==0) ) addch('-');
 while( cows-- > 0 ) addstr("O");
 while( bulls-- > 0 ) addstr("X");
 yp++;
 if ( yp > LAST_LINE ) {
   yp = LINE_BEGIN;
   xp += 10;
 }
 return false;

}

bool ask_play_again() {

 int i;
 while(yp-- >= LINE_BEGIN) {
   move(yp, 0); clrtoeol();
 }
 yp = LINE_BEGIN; xp = 0;
 move(21,0); clrtoeol();
 addstr("Do you want to play again? [y/n]");
 while(true) {
   int a = getch();
   switch(a) {
   case 'y':
   case 'Y':
     return true;
   case 'n':
   case 'N':
     return false;
   }
 }

}


int main() {

 bool bingo, again;
 int tries = 0;
 initscr(); cbreak(); noecho();
 clear();
 number[4] = guess[4] = 0;
 mvaddstr(0,0, "I choose a number made of 4 digits (from 1 to 9) without repetitions\n"
               "You enter a number of 4 digits, and I say you how many of them are\n"
               "in my secret number but in wrong position (cows or O), and how many\n"
               "are in the right position (bulls or X)");
 do {
   move(20,0); clrtoeol(); move(21, 0); clrtoeol();
   srand(time(NULL));
   choose_the_number();
   do {
     ask_for_a_number();
     bingo = take_it_or_not();
     tries++;
   } while(!bingo && (tries < MAX_NUM_TRIES));
   if ( bingo ) 
     mvaddstrf(20, 0, "You guessed %s correctly in %d attempts!", number, tries);
   else
     mvaddstrf(20,0, "Sorry, you had only %d tries...; the number was %s", 

MAX_NUM_TRIES, number);

   again = ask_play_again();
   tries = 0; 
 } while(again);
 nocbreak(); echo(); endwin();
 return EXIT_SUCCESS;

}</lang>

C++

<lang cpp>#include <iostream>

  1. include <string>
  2. include <algorithm>
  3. include <cstdlib>

bool contains_duplicates(std::string s) {

 std::sort(s.begin(), s.end());
 return std::adjacent_find(s.begin(), s.end()) != s.end();

}

void game() {

 typedef std::string::size_type index;
 std::string symbols = "0123456789";
 unsigned int const selection_length = 4;
 std::random_shuffle(symbols.begin(), symbols.end());
 std::string selection = symbols.substr(0, selection_length);
 std::string guess;
 while (std::cout << "Your guess? ", std::getline(std::cin, guess))
 {
   if (guess.length() != selection_length
       || guess.find_first_not_of(symbols) != std::string::npos
       || contains_duplicates(guess))
   {
     std::cout << guess << " is not a valid guess!";
     continue;
   }
   unsigned int bulls = 0;
   unsigned int cows = 0;
   for (index i = 0; i != selection_length; ++i)
   {
     index pos = selection.find(guess[i]);
     if (pos == i)
       ++bulls;
     else if (pos != std::string::npos)
       ++cows;
   }
   std::cout << bulls << " bulls, " << cows << " cows.\n";
   if (bulls == selection_length)
   {
     std::cout << "Congratulations! You have won!\n";
     return;
   }
 }
 std::cerr << "Oops! Something went wrong with input, or you've entered end-of-file!\nExiting ...\n";
 std::exit(EXIT_FAILURE);

}

int main() {

 std::cout << "Welcome to bulls and cows!\nDo you want to play? ";
 std::string answer;
 while (true)
 {
   while (true)
   {
     if (!std::getline(std::cin, answer))
     {
       std::cout << "I can't get an answer. Exiting.\n";
       return EXIT_FAILURE;
     }
     if (answer == "yes" || answer == "Yes" || answer == "y" || answer == "Y")
       break;
     if (answer == "no" || answer == "No" || answer == "n" || answer == "N")
     {
       std::cout << "Ok. Goodbye.\n";
       return EXIT_SUCCESS;
     }
     std::cout << "Please answer yes or no: ";
   }
   game(); 
   std::cout << "Another game? ";
 }

}</lang>

C#

<lang csharp>using System;

namespace BullsnCows {

   class Program
   {
       
       static void Main(string[] args)
       {
           int[] nums = new int[] { 1, 2, 3, 4, 5, 6, 7, 8, 9 };
           KnuthShuffle<int>(ref nums);
           int[] chosenNum = new int[4];
           Array.Copy(nums, chosenNum, 4);
           Console.WriteLine("Your Guess ?");
           while (!game(Console.ReadLine(), chosenNum))
           {
               Console.WriteLine("Your next Guess ?");
           }
           
           Console.ReadKey();
       }
       public static void KnuthShuffle<T>(ref T[] array)
       {
           System.Random random = new System.Random();
           for (int i = 0; i < array.Length; i++)
           {
               int j = random.Next(array.Length);
               T temp = array[i]; array[i] = array[j]; array[j] = temp;
           }
       }
       public static bool game(string guess, int[] num)
       {
           char[] guessed = guess.ToCharArray();
           int bullsCount = 0, cowsCount = 0;
           if (guessed.Length != 4)
           {
               Console.WriteLine("Not a valid guess.");
               return false;
           }
           for (int i = 0; i < 4; i++)
           {
               int curguess = (int) char.GetNumericValue(guessed[i]);
               if (curguess < 1 || curguess > 9)
               {
                   Console.WriteLine("Digit must be ge greater 0 and lower 10.");
                   return false;
               }
               if (curguess == num[i])
               {
                   bullsCount++;
               }
               else
               {
                   for (int j = 0; j < 4; j++)
                   {
                       if (curguess == num[j])
                           cowsCount++;
                   }
               }
           }
           if (bullsCount == 4)
           {
               Console.WriteLine("Congratulations! You have won!");
               return true;
           }
           else
           {
               Console.WriteLine("Your Score is {0} bulls and {1} cows", bullsCount, cowsCount);
               return false;
           }
       }
   }

} </lang>

Clojure

<lang clojure> (ns bulls-and-cows)

(defn bulls [guess solution]

 (count (filter true? (map = guess solution))))

(defn cows [guess solution]

 (-
  (count (filter (set solution) guess))
  (bulls guess solution)))

(defn valid-input?

 "checks whether the string is a 4 digit number with unique digits"
 [user-input]
 (if (re-seq #"^(?!.*(\d).*\1)\d{4}$" user-input)
   true
   false))

(defn enter-guess []

 "Let the user enter a guess. Verify the input. Repeat until valid.

returns a list of digits enters by the user (# # # #)"

   (println "Enter your guess: ")
   (let [guess (read-line)]
     (if (valid-input? guess)
       (map #(Character/digit % 10) guess)
       (recur))))

(defn bulls-and-cows []

 "generate a random 4 digit number from the list of (1 ... 9): no repeating digits

player tries to guess the number with bull and cows rules gameplay"

 (let [solution ( take 4 (shuffle (range 1 10)))]
   (println "lets play some bulls and cows!")
   (loop [guess (enter-guess)]
     (println (bulls guess solution) " bulls and " (cows guess solution) " cows.")
     (if (not= guess solution)
       (recur (enter-guess))
       (println "You have won!")))))

(bulls-and-cows) </lang>

Common Lisp

<lang lisp>(defun get-number ()

 (do ((digits '()))
     ((>= (length digits) 4) digits)
   (pushnew (1+ (random 9)) digits)))

(defun compute-score (guess number)

 (let ((cows  0)
       (bulls 0))
   (map nil (lambda (guess-digit number-digit)
              (cond ((= guess-digit number-digit) (incf bulls))
                    ((member guess-digit number)  (incf cows))))
        guess number)
   (values cows bulls)))

(defun number->guess (number)

 (when (integerp number)
   (do ((digits '()))
       ((zerop number) digits)
     (multiple-value-bind (quotient remainder) (floor number 10)
       (push remainder digits)
       (setf number quotient)))))

(defun valid-guess-p (guess)

 (and (= 4 (length guess))
      (every (lambda (digit) (<= 1 digit 9)) guess)
      (equal guess (remove-duplicates guess))))

(defun play-game (&optional (stream *query-io*))

 (do ((number (get-number))
      (cows   0)
      (bulls  0))
     ((= 4 bulls))
   (format stream "~&Guess a 4-digit number: ")
   (let ((guess (number->guess (read stream))))
     (cond ((not (valid-guess-p guess))
            (format stream "~&Malformed guess."))
           (t
            (setf (values cows bulls) (compute-score guess number))
            (if (= 4 bulls)
              (format stream "~&Correct, you win!")
              (format stream "~&Score: ~a cows, ~a bulls."
                      cows bulls)))))))</lang>

D

<lang d>import std.stdio, std.random, std.string, std.algorithm,

      std.range, std.conv;

void main() {

 enum size = 4;
 immutable ddigits = "123456789"d;
 //immutable chosen = ddigits.randomCover.take(size).array;
 const chosen = ddigits.randomCover(rndGen).take(size).array;
 writeln("Guess a number composed of ", size,
         " unique digits from 1 to 9 in random order.");
 uint nGuesses;
 while (true) {
   nGuesses++;
   dstring guess;
   while (true) {
     writef("\nNext guess (%d): ", nGuesses);
     guess = readln.strip.dtext;
     if (guess.countchars(ddigits) == size &&
         guess.dup.sort().uniq.walkLength == size)
       break;
     writefln("I need %d unique digits from 1 to 9, no spaces", size);
   }
   if (guess == chosen) {
     writefln("\nYou guessed correctly in %d attempts.", nGuesses);
     break;
   }
   immutable bulls = zip(guess, chosen).count!q{ a[0] == a[1] };
   immutable cows = iota(size)
                    .count!(i => guess[i] != chosen[i] &&
                                 chosen.canFind(guess[i]));
   writefln("  %d Bulls\n  %d Cows", bulls, cows);
 }

}</lang>

Output:
Guess a number composed of 4 unique digits from 1 to 9 in random order.

Next guess (1): 123
I need 4 unique digits from 1 to 9, no spaces

Next guess (1): 1234
  1 Bulls
  1 Cows

Next guess (2): 5296
  2 Bulls
  0 Cows

Next guess (3): 5217

You guessed correctly in 3 attempts.

E

Note: This example was deliberately written in an abstracted style, separating out the algorithms, game logic, and UI.

<lang e>def Digit := 1..9 def Number := Tuple[Digit,Digit,Digit,Digit]

/** Choose a random number to be guessed. */ def pick4(entropy) {

   def digits := [1,2,3,4,5,6,7,8,9].diverge()
   
   # Partial Fisher-Yates shuffle
   for i in 0..!4 {
       def other := entropy.nextInt(digits.size() - i) + i
       def t := digits[other]
       digits[other] := digits[i]
       digits[i] := t
   }
   return digits(0, 4)

}

/** Compute the score of a guess. */ def scoreGuess(actual :Number, guess :Number) {

   var bulls := 0
   var cows := 0
   for i => digit in guess {
       if (digit == actual[i]) {
           bulls += 1
       } else if (actual.indexOf1(digit) != -1) {
           cows += 1
       }
   }
   return [bulls, cows]

}

/** Parse a guess string into a list of digits (Number). */ def parseGuess(guessString, fail) :Number {

   if (guessString.size() != 4) {
       return fail(`I need four digits, not ${guessString.size()} digits.`)
   } else {
       var digits := []
       for c in guessString {
           if (('1'..'9')(c)) {
               digits with= c - '0'
           } else {
               return fail(`I need a digit from 1 to 9, not "$c".`)
           }
       }
       return digits
   }  

}

/** The game loop: asking for guesses and reporting scores and win conditions.

   The return value is null or a broken reference if there was a problem. */

def bullsAndCows(askUserForGuess, tellUser, entropy) {

   def actual := pick4(entropy)
   
   def gameTurn() {
       return when (def guessString := askUserForGuess <- ()) -> {
           escape tellAndContinue {
               def guess := parseGuess(guessString, tellAndContinue)                
               def [bulls, cows] := scoreGuess(actual, guess)
               
               if (bulls == 4) {
                   tellUser <- (`You got it! The number is $actual!`)
                   null
               } else {
                   tellAndContinue(`Your score for $guessString is $bulls bulls and $cows cows.`)
               }
               
           } catch message {
               # The parser or scorer has something to say, and the game continues afterward
               when (tellUser <- (message)) -> {
                   gameTurn()
               }
           }
       } catch p {
           # Unexpected problem of some sort
           tellUser <- ("Sorry, game crashed.")
           throw(p)
       }
   }
   
   return gameTurn()

}</lang>

REPL user interface

def replBullsAndCows() {
    when (
        bullsAndCows(fn {
            def [guess, env] := e`def guess; guess`.evalToPair(interp.getTopScope().nestOuter())
            interp.setTopScope(env)
            println("Please type “ bind guess := \"your guess here\" ”.")
            guess
        }, println, entropy)
    ) -> {} catch p {
      println(`$p${p.eStack()}`)
    }
}

Graphical user interface

Works with: E-on-Java

(Java Swing)

<lang e>def guiBullsAndCows() {

   var lastGuess := ""
   def op := <unsafe:javax.swing.makeJOptionPane>
   return bullsAndCows(fn {
     lastGuess := op.showInputDialog(null, "Enter your guess:", lastGuess)
     if (lastGuess == null) {
       # canceled, so just fail to return an answer and let the game logic get GCed
       Ref.promise()[0]
     } else {
       lastGuess
     }
   }, fn msg {
     op.showMessageDialog(null, msg)
   }, entropy)

}</lang>

Elena

<lang elena>#define std'dictionary'*.

  1. define std'basic'*.
  2. define std'collections'*.
  3. define std'patterns'*.
  4. define ext'utils'*.
  5. define std'routines'arrays'*.
  1. class EDigitProp

{

   #method get
   [
       ^ self numeric - 30h.
   ]

}

  1. symbol Digits : aLiteral
   = Summing &&var:List &prop:EDigitProp start:Scan::aLiteral.
  1. class GameMaster

{

   #field theNumbers.
   #initializer
   [
       // generate secret number
       #var aRandomNumbers := Randomized &&base:(1,2,3,4,5,6,7,8,9) &count:9.
       
       theNumbers := aRandomNumbers~earrayop read &from:0 &to:3 &:esubarray.
   ]
   #method proceed : aGuess
   [
       #if (aGuess count != 4)?
       [
           'program'output << "Not a valid guess.%n".
           
           ^ $self.
       ].
       #var aCows := Integer::0.
       #var aBulls := Integer::0.
               
       #if It::aGuess run: aNumber =
       [
           // check range
           Control if:(aNumber > 0) if:(aNumber < 10).
           
           // check duplicates
           #if (aNumber indexer'clone index'append:1)~EIt find:aNumber
           [
               control fail.
           ].
           
           #if Control if:(aNumber == theNumbers@aNumber index)
           [
               aBulls += 1.
           ]
           | if:(Scan::theNumbers == aNumber)
           [
               aCows += 1.
           ].
       ]
       | [
           'program'output << "Not a valid guess.%n".
           
           ^ $self.
       ].        
       
       #if (aBulls == 4)?
       [
           'program'output << "%nCongratulations! You have won!".
           
           $self fail.
       ]
       | [
           'program'output << "%nYour Score is " << aBulls << " bulls and " << aCows << " cows%n".
       ].
   ]

}

  1. symbol Program =

[

   #var aGameMaster := GameMaster.
   #while aGameMaster proceed:Digits::(ext'io'console << "Your Guess ?" >> String).

].</lang>

Erlang

Module: <lang erlang>-module(bulls_and_cows). -export([generate_secret/0, score_guess/2, play/0]).

% generate the secret code generate_secret() -> generate_secret([], 4, lists:seq(1,9)). generate_secret(Secret, 0, _) -> Secret; generate_secret(Secret, N, Digits) ->

 Next = lists:nth(random:uniform(length(Digits)), Digits),
 generate_secret(Secret ++ [Next], N - 1, Digits -- [Next]).

% evaluate a guess score_guess(Secret, Guess)

 when length(Secret) =/= length(Guess) -> throw(badguess);

score_guess(Secret, Guess) ->

 Bulls = count_bulls(Secret,Guess),
 Cows = count_cows(Secret, Guess, Bulls),
 [Bulls, Cows].

% count bulls (exact matches) count_bulls(Secret, Guess) ->

 length(lists:filter(fun(I) -> lists:nth(I,Secret) == lists:nth(I,Guess) end,
                     lists:seq(1, length(Secret)))).

% count cows (digits present but out of place) count_cows(Secret, Guess, Bulls) ->

  length(lists:filter(fun(I) -> lists:member(I, Guess) end, Secret)) - Bulls.

% play a game play() -> play_round(generate_secret()).

play_round(Secret) -> play_round(Secret, read_guess()).

play_round(Secret, Guess) ->

 play_round(Secret, Guess, score_guess(Secret,Guess)).

play_round(_, _, [4,0]) ->

 io:put_chars("Correct!\n");

play_round(Secret, _, Score) ->

 io:put_chars("\tbulls:"), io:write(hd(Score)), io:put_chars(", cows:"),
 io:write(hd(tl(Score))), io:put_chars("\n"), play_round(Secret).

read_guess() ->

 lists:map(fun(D)->D-48 end,
   lists:sublist(io:get_line("Enter your 4-digit guess: "), 4)).</lang>

Script: <lang erlang>#!/usr/bin/escript % Play Bulls and Cows main(_) -> random:seed(now()), bulls_and_cows:play().</lang>

Sample play:

Enter your 4-digit guess: 8376
	bulls:1, cows:0
Enter your 4-digit guess: 8941
	bulls:1, cows:1
Enter your 4-digit guess: 8529
	bulls:1, cows:1
Enter your 4-digit guess: 4926
	bulls:1, cows:1
Enter your 4-digit guess: 9321
Correct!

Euphoria

Works with: Euphoria version 4.0.3, 4.0.0 RC1 and later

<lang euphoria>include std\text.e include std\os.e include std\sequence.e include std\console.e

sequence bcData = {0,0} --bull,cow score for the player sequence goalNum = { {0,0,0,0}, {0,0,0,0}, 0} --computer's secret number digits (element 1), marked as bull/cow --indexes in element 2, integer value of it in element 3 sequence currentGuess = { {0,0,0,0}, {0,0,0,0}, 0} --player's guess, same format as goalNum sequence removeChars = 0 & " 0\r\t\n" --characters to trim (remove) from user's input. \r, \t are single escaped characters, --0 is ascii 0x0 and number zero is ascii 48, or 0x30. The rest are wysiwyg integer tries = 0 --track number of tries to guess the number sequence bcStrings ={"bull", "cow"} --stores singular and/or plural strings depending on score in bcData

goalNum[1] = rand( {9,9,9,9} ) --rand function works on objects. here it outputs into each sequence element. goalNum[3] = goalNum[1][1] * 1000 + goalNum[1][2] * 100 + goalNum[1][3] * 10 + goalNum[1][4] --convert digits to an integer --and store it

procedure getInputAndProcess(integer stage = 1) --object = 1 sets default value for the parameter if it isn't specified

   goalNum[2][1..4] = 0 --{0,0,0,0} --set these to unscaned (0) since the scanning will start over. 
   currentGuess[1][1..4] = 0 --{0,0,0,0} --these too, or they will contain old marks
   currentGuess[2][1..4] = 0
   tries += 1 --equivalent to tries = tries + 1, but faster and shorter to write
   bcData[1..2] = 0 -- {0,0}
   if stage <= 1 then --if this process was run for the first time or with no parameters, then..
       puts(1,"The program has thought of a four digit number using only digits 1 to 9.\nType your guess and press enter.\n")
   end if
   
   while 1 label "guesscheck" do --labels can be used to specify a jump point from exit or retry, and help readability
       currentGuess[1] = trim(gets(0), removeChars) --get user input, trim unwanted characters from it, store it in currentGuess[1]
       currentGuess[1] = mapping( currentGuess[1], {49,50,51,52,53,54,55,56,57}, {1,2,3,4,5,6,7,8,9} ) --convert ascii codes to
       -- integer digits they represent
       integer tempF = find('0',currentGuess[1])
       if length(currentGuess[1]) != 4 or tempF != 0 then --if the input string is now more than 4 characters/integers,
           --the input won't be used.
           puts(1,"You probably typed too many digits or a 0. Try typing a new 4 digit number with only numbers 1 through 9.\n")
           retry "guesscheck"
           else
               exit "guesscheck"
       end if
   end while
   --convert separate digits to the one integer they represent and store it, like with goalNum[3]
   currentGuess[3] = currentGuess[1][1] * 1000 + currentGuess[1][2] * 100 + currentGuess[1][3] * 10 + currentGuess[1][4] 

--convert digits to the integer they represent, to print to a string later

   --check for bulls
   for i = 1 to 4 do
       if goalNum[1][i] = currentGuess[1][i] then
           goalNum[2][i] = 1
           currentGuess[2][i] = 1
           bcData[1] += 1
       end if
   end for
   --check for cows, but not slots marked as bulls or cows already.
   for i = 1 to 4 label "iGuessElem"do --loop through each guessed digit
       for j = 1 to 4 label "jGoalElem" do --but first go through each goal digit, comparing the first guessed digit,
           --and then the other guessed digits 2 through 4
       
           if currentGuess[2][i] = 1 then --if the guessed digit we're comparing right now has been marked as bull or cow already
               continue "iGuessElem" --skip to the next guess digit without comparing this guess digit to the other goal digits
           end if
       
           if goalNum[2][j] = 1 then --if the goal digit we're comparing to right now has been marked as a bull or cow already
               continue "jGoalElem" --skip to the next goal digit
           end if
       
           if currentGuess[1][i] = goalNum[1][j] then --if the guessed digit is the same as the goal one, 
               --it won't be a bull, so it's a cow
               bcData[2] += 1 --score one more cow
               goalNum[2][j] = 1 --mark this digit as a found cow in the subsequence that stores 0's or 1's as flags
               continue "iGuessElem" --skip to the next guess digit, so that this digit won't try to check for
               --matches(cow) with other goal digits
           end if
       
       end for --this guess digit was compared to one goal digit , try comparing this guess digit with the next goal digit
   end for --this guess digit was compared with all goal digits, compare the next guess digit to all the goal digits
   if bcData[1] = 1 then --uses singular noun when there is score of 1, else plural
       bcStrings[1] = "bull"
       else
           bcStrings[1] = "bulls"
   end if
   if bcData[2] = 1 then --the same kind of thing as above block
       bcStrings[2] = "cow"
       else
           bcStrings[2] = "cows"
   end if
   if bcData[1] < 4 then --if less than 4 bulls were found, the player hasn't won, else they have...
       printf(1, "Guess #%d : You guessed %d . You found %d %s, %d %s. Type new guess.\n", {tries, currentGuess[3], bcData[1], bcStrings[1], bcData[2], bcStrings[2]} )
       getInputAndProcess(2)
   else --else they have won and the procedure ends
       printf(1, "The number was %d. You guessed %d in %d tries.\n", {goalNum[3], currentGuess[3], tries} )
       any_key()--wait for keypress before closing console window. 
   end if

end procedure --run the procedure getInputAndProcess(1)


</lang> Output :

The program has thought of a four digit number using only digits 1 to 9.
Type your guess and press enter.
7456
Guess #1 : You guessed 7456 . You found 1 bull, 1 cow. Type new guess.
7116
Guess #2 : You guessed 7116 . You found 1 bull, 0 cows. Type new guess.
7862
Guess #3 : You guessed 7862 . You found 0 bulls, 2 cows. Type new guess.
1826
[...etc]
6586
Guess #10 : You guessed 6586 . You found 3 bulls, 0 cows. Type new guess.
5586
Guess #11 : You guessed 5586 . You found 3 bulls, 0 cows. Type new guess.
2586
Guess #12 : You guessed 2586 . You found 3 bulls, 0 cows. Type new guess.
9586
The number was 9586. You guessed 9586 in 13 tries.
Press Any Key to continue...

Factor

<lang Factor>USING: accessors assocs combinators fry grouping hashtables kernel

      locals math math.parser math.ranges random sequences strings
      io ascii ;
  

IN: bullsncows

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 )
   [ 1string string>number ] { } 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 ;
main ( -- ) new-number drop narr>nhash main-loop ;</lang>

Fan

<lang Fan>**

    • Bulls and cows. A game pre-dating, and similar to, Mastermind.

class BullsAndCows {

 Void main()
 {
   digits := [1,2,3,4,5,6,7,8,9]
   size := 4
   chosen := [,]
   size.times { chosen.add(digits.removeAt(Int.random(0..<digits.size))) }
   echo("I've chosen $size unique digits from 1 to 9 at random.
         Try to guess my number!")
   guesses := 0
   while (true) // game loop
   {
     guesses += 1
     guess := Int[,]
     while (true) // input loop
     {
       // get a good guess
       Sys.out.print("\nNext guess [$guesses]: ")
       Sys.out.flush
       inString := Sys.in.readLine?.trim ?: ""
       inString.each |ch|
       { if (ch >= '1' && ch <= '9' && !guess.contains(ch)) guess.add(ch-'0') }
       if (guess.size == 4)
         break // input loop
       echo("Oops, try again. You need to enter $size unique digits from 1 to 9")
     }
     if (guess.all |v, i->Bool| { return v == chosen[i] })
     {
       echo("\nCongratulations! You guessed correctly in $guesses guesses")
       break // game loop
     }
     bulls := 0
     cows  := 0
     (0 ..< size).each |i|
     {
       if (guess[i] == chosen[i])
         bulls += 1
       else if (chosen.contains(guess[i]))
         cows += 1
     }
     echo("\n  $bulls Bulls\n  $cows Cows")
   }
 }

}</lang>

Forth

Works with: GNU Forth

<lang forth>include random.fs

create hidden 4 allot

ok? ( str -- ? )
 dup 4 <> if 2drop false exit then
 1 9 lshift 1- -rot
 bounds do
   i c@ '1 -
   dup 0 9 within 0= if 2drop false leave then
   1 swap lshift over and
   dup 0= if nip leave then
   xor
 loop 0<> ;
init
 begin
   hidden 4 bounds do 9 random '1 + i c! loop
   hidden 4 ok?
 until ;
check? ( addr -- solved? )
 0
 4 0 do
   over i + c@
   4 0 do
     dup hidden i + c@ = if     swap
       i j = if 8 else 1 then + swap
     then
   loop drop
 loop nip
 8 /mod tuck . ." bulls, " . ." cows"
 4 = ;
guess: ( "1234" -- )
 bl parse 2dup ok? 0= if 2drop ." Bad guess! (4 unique digits, 1-9)" exit then
 drop check? if cr ." You guessed it!" then ;</lang>
init  ok
guess: 1234 1 bulls, 0 cows ok
guess: 1567 1 bulls, 1 cows ok
guess: 1895 2 bulls, 1 cows ok
guess: 1879 4 bulls, 0 cows
You guessed it! ok

Fortran

Works with: Fortran version 90 and later

<lang fortran>module bac

 implicit none

contains

 subroutine Gennum(n)
   integer, intent(out) :: n(4)
   integer :: i, j
   real :: r
     
   call random_number(r)
   n(1) = int(r * 9.0) + 1
   i = 2
   

outer: do while (i <= 4)

        call random_number(r)
        n(i) = int(r * 9.0) + 1

inner: do j = i-1 , 1, -1

          if (n(j) == n(i)) cycle outer
        end do inner
        i = i + 1
      end do outer

 end subroutine Gennum
 subroutine Score(n, guess, b, c) 
   character(*), intent(in) :: guess
   integer, intent(in) :: n(0:3)
   integer, intent(out) :: b, c
   integer :: digit, i, j, ind
  
   b = 0; c = 0
   do i = 1, 4
     read(guess(i:i), "(i1)") digit
     if (digit == n(i-1)) then
       b = b + 1
     else
       do j = i, i+2
         ind = mod(j, 4)
         if (digit == n(ind)) then
           c = c + 1
           exit
         end if
       end do    
     end if
   end do  
end subroutine Score  

end module bac

program Bulls_and_Cows

  use bac
  implicit none
  
  integer :: n(4)
  integer :: bulls=0, cows=0, tries=0
  character(4) :: guess
  call random_seed
  call Gennum(n)
  
  write(*,*) "I have selected a number made up of 4 digits (1-9) without repetitions."
  write(*,*) "You attempt to guess this number."
  write(*,*) "Every digit in your guess that is in the correct position scores 1 Bull"
  write(*,*) "Every digit in your guess that is in an incorrect position scores 1 Cow"
  write(*,*)
  do while (bulls /= 4)
    write(*,*) "Enter a 4 digit number"
    read*, guess
    if (verify(guess, "123456789") /= 0) then
      write(*,*) "That is an invalid entry. Please try again."
      cycle
    end if
    tries = tries + 1
    call Score (n, guess, bulls, cows)
    write(*, "(a, i1, a, i1, a)") "You scored ", bulls, " bulls and ", cows, " cows"
    write(*,*)
  end do
  write(*,"(a,i0,a)") "Congratulations! You correctly guessed the correct number in ", tries, " attempts"

end program Bulls_and_Cows</lang>

Go

<lang go>package main

import (

   "bufio"
   "bytes"
   "fmt"
   "math/rand"
   "os"
   "strings"
   "time"

)

func main() {

   fmt.Println(`Cows and Bulls

Guess four digit number of unique digits in the range 1 to 9. A correct digit but not in the correct place is a cow. A correct digit in the correct place is a bull.`)

   // generate pattern
   pat := make([]byte, 4)
   rand.Seed(time.Now().Unix())
   r := rand.Perm(9)
   for i := range pat {
       pat[i] = '1' + byte(r[i])
   }
   // accept and score guesses
   valid := []byte("123456789")

guess:

   for in := bufio.NewReader(os.Stdin); ; {
       fmt.Print("Guess: ")
       guess, err := in.ReadString('\n')
       if err != nil {
           fmt.Println("\nSo, bye.")
           return
       }
       guess = strings.TrimSpace(guess)
       if len(guess) != 4 {
           // malformed:  not four characters
           fmt.Println("Please guess a four digit number.")
           continue
       }
       var cows, bulls int
       for ig, cg := range guess {
           if strings.IndexRune(guess[:ig], cg) >= 0 {
               // malformed:  repeated digit
               fmt.Printf("Repeated digit: %c\n", cg)
               continue guess
           }
           switch bytes.IndexByte(pat, byte(cg)) {
           case -1:
               if bytes.IndexByte(valid, byte(cg)) == -1 {
                   // malformed:  not a digit
                   fmt.Printf("Invalid digit: %c\n", cg)
                   continue guess
               }
           default: // I just think cows should go first
               cows++
           case ig:
               bulls++
           }
       }
       fmt.Printf("Cows: %d, bulls: %d\n", cows, bulls)
       if bulls == 4 {
           fmt.Println("You got it.")
           return
       }
   }

}</lang> Alternate Solution <lang go>package main

import ( . "fmt" "rand" "time" "os" "bufio" "strconv" "strings" )

func generateTarget() int { rand.Seed(time.Nanoseconds()) // loop until we find a number that doesn't have dupes for { target := rand.Intn(9000) + 1000 if !hasDupes(target) { return target } } panic("Crap.") }

func hasDupes(num int) bool { digs := make([]bool, 10) for num > 0 { if digs[num%10] { return true } digs[num%10] = true num /= 10 } return false }

func askForNumber() (int, os.Error) { in := bufio.NewReader(os.Stdin)

for { Print("Give me a number: ") line, err := in.ReadString('\n')

if err != nil { return -1, err }

// Strip off the \n line = line[0 : len(line)-1] number, err := strconv.Atoi(line)

switch { case err != nil: Println("Give me a number fule!") case number < 1000: Println("Number not long enough") case number > 9999: Println("Number is to big") case hasDupes(number): Println("I said no dupes!") default: return number, nil } // Keep Asking } panic("Crap.") }

func bullsAndCows(number int, guess int) (bulls int, cows int) { bulls, cows = 0, 0 numberstr := strconv.Itoa(number) guessstr := strconv.Itoa(guess)

for i := range guessstr { s := string(guessstr[i]) switch { case guessstr[i] == numberstr[i]: bulls++ case strings.Index(numberstr, s) >= 0: cows++ } } return; }

func main() { attempts := 0

Print("I choose a number made of 4 digits (from 1 to 9) without repetitions\n" "You enter a number of 4 digits, and I say you how many of them are\n" "in my secret number but in wrong position (cows or O), and how many\n" "are in the right position (bulls or X)\n\n")

target := generateTarget()

for { guess, err := askForNumber() attempts++

// Handle err if err != nil && err != os.EOF { Print(err) } else if err == os.EOF { return }

// Check if target matches guess if guess == target { Printf("Congratulations you guessed correctly in %d attempts\n", attempts) return }

bulls, cows := bullsAndCows(target, guess) Printf("%d Bulls, %d Cows\n", bulls, cows) }

}</lang>

Haskell

<lang haskell>import Data.List (partition, intersect, nub) import Control.Monad import System.Random (StdGen, getStdRandom, randomR) import Text.Printf

numberOfDigits = 4 :: Int

main = bullsAndCows

bullsAndCows :: IO () bullsAndCows = do

   digits <- getStdRandom $ pick numberOfDigits ['1' .. '9']
   putStrLn "Guess away!"
   loop digits
 where loop digits = do
           input <- getLine
           if okay input
             then
                 let (bulls, cows) = score digits input in
                 if bulls == numberOfDigits then
                     putStrLn "You win!"
                 else do
                     printf "%d bulls, %d cows.\n" bulls cows
                     loop digits
             else do
                 putStrLn "Malformed guess; try again."
                 loop digits
       okay :: String -> Bool
       okay input =
           length input == numberOfDigits && 
           input == nub input &&
           all legalchar input
         where legalchar c = '1' <= c && c <= '9'
       score :: String -> String -> (Int, Int)
       score secret guess = (length bulls, cows)
         where (bulls, nonbulls) = partition (uncurry (==)) $
                   zip secret guess
               cows = length $ uncurry intersect $ unzip nonbulls

pick :: Int -> [a] -> StdGen -> ([a], StdGen) {- Randomly selects items from a list without replacement. -} pick n l g = f n l g (length l - 1) []

 where  f 0 _ g _   ps = (ps, g)
        f n l g max ps =
            f (n - 1) (left ++ right) g' (max - 1) (picked : ps)
         where (i, g') = randomR (0, max) g
               (left, picked : right) = splitAt i l</lang>

Icon and Unicon

The following works in both Icon and Unicon.

<lang Unicon>procedure main()

   digits := "123456789"
   every !digits :=: ?digits
   num := digits[1+:4]
   repeat if score(num, getGuess(num)) then break
   write("Good job.")

end

procedure getGuess(num)

   repeat {
       writes("Enter a guess: ")
       guess := read() | stop("Quitter!")
       if *(guess ** '123456789') == *num then return guess
       write("Malformed guess: ",guess,". Try again.")
       }

end

procedure score(num, guess)

   bulls := 0
   cows := *(num ** guess)
   every (num[i := 1 to *num] == guess[i], bulls +:= 1, cows -:= 1)
   write("\t",bulls," bulls and ",cows," cows")
   return (bulls = *num)

end</lang>

J

<lang j>require 'misc'

plural=: conjunction define

(":m),' ',n,'s'#~1~:m

)

bullcow=:monad define

 number=. 1+4?9
 whilst. -.guess-:number do.
   guess=. 0 "."0 prompt 'Guess my number: '
   if. (4~:#guess)+.(4~:#~.guess)+.0 e.guess e.1+i.9 do.
     if. 0=#guess do.
       smoutput 'Giving up.'
       return.
     end.
     smoutput 'Guesses must be four different non-zero digits'
     continue.
   end.
   bulls=. +/guess=number
   cows=. (+/guess e.number)-bulls
   smoutput bulls plural 'bull',' and ',cows plural 'cow','.'
 end.
 smoutput 'you win'

)</lang>

For example:

<lang j> bullcow Guess my number: 1234 0 bulls and 1 cow. Guess my number: 5678 3 bulls and 0 cows. Guess my number: 2349 0 bulls and 0 cows. Guess my number: 1567 0 bulls and 3 cows. Guess my number: 6178 3 bulls and 0 cows. Guess my number: 6157 1 bull and 2 cows. Guess my number: 5178 4 bulls and 0 cows. you win</lang>

Java

<lang java5>import java.util.InputMismatchException; import java.util.Random; import java.util.Scanner;

public class BullsAndCows{ public static void main(String[] args){ Random gen= new Random(); int target= 0; while(hasDupes(target= (gen.nextInt(9000) + 1000))); String targetStr = target +""; boolean guessed = false; Scanner input = new Scanner(System.in); int guesses = 0; do{ int bulls = 0; int cows = 0; System.out.print("Guess a 4-digit number with no duplicate digits: "); int guess; try{ guess = input.nextInt(); if(hasDupes(guess) || guess < 1000) continue; }catch(InputMismatchException e){ continue; } guesses++; String guessStr = guess + ""; for(int i= 0;i < 4;i++){ if(guessStr.charAt(i) == targetStr.charAt(i)){ bulls++; }else if(targetStr.contains(guessStr.charAt(i)+"")){ cows++; } } if(bulls == 4){ guessed = true; }else{ System.out.println(cows+" Cows and "+bulls+" Bulls."); } }while(!guessed); System.out.println("You won after "+guesses+" guesses!"); }

public static boolean hasDupes(int num){ boolean[] digs = new boolean[10]; while(num > 0){ if(digs[num%10]) return true; digs[num%10] = true; num/= 10; } return false; } }</lang> Output:

Guess a 4-digit number with no duplicate digits: 5834
2 Cows and 0 Bulls.
Guess a 4-digit number with no duplicate digits: 1234
1 Cows and 0 Bulls.
Guess a 4-digit number with no duplicate digits: 4321
1 Cows and 0 Bulls.
Guess a 4-digit number with no duplicate digits: 3421
0 Cows and 1 Bulls.
Guess a 4-digit number with no duplicate digits: 8412
0 Cows and 0 Bulls.
Guess a 4-digit number with no duplicate digits: 3560
1 Cows and 1 Bulls.
Guess a 4-digit number with no duplicate digits: 3650
0 Cows and 2 Bulls.
Guess a 4-digit number with no duplicate digits: 3759
2 Cows and 2 Bulls.
Guess a 4-digit number with no duplicate digits: 3975
2 Cows and 2 Bulls.
Guess a 4-digit number with no duplicate digits: 3957
You won after 10 guesses!

JavaScript

Spidermonkey version

<lang javascript>#!/usr/bin/env js

function main() {

   var len = 4;
   playBullsAndCows(len);

}

function playBullsAndCows(len) {

   var num = pickNum(len);
   // print('The secret number is:\n  ' + num.join('\n  '));
   showInstructions(len);
   var nGuesses = 0;
   while (true) {
       nGuesses++;
       var guess = getGuess(nGuesses, len);
       var census = countBovine(num, guess);
       showScore(census.bulls, census.cows);
       if (census.bulls == len) {
           showFinalResult(nGuesses);
           return;
       }
   }

}

function showScore(nBulls, nCows) {

   print('    Bulls: ' + nBulls + ', cows: ' + nCows);

}

function showFinalResult(guesses) {

   print('You win!!! Guesses needed: ' + guesses);

}

function countBovine(num, guess) {

   var count = {bulls:0, cows:0};
   var g = guess.join();
   for (var i = 0; i < num.length; i++) {
       var digPresent = g.search(num[i]) != -1;
       if (num[i] == guess[i]) count.bulls++;
       else if (digPresent) count.cows++;
   }
   return count;

}

function getGuess(nGuesses, len) {

   while (true) {
       putstr('Your guess #' + nGuesses + ': ');
       var guess = readline();
       guess = String(parseInt(guess)).split();
       if (guess.length != len) {
           print('  You must enter a ' + len + ' digit number.');
           continue;
       }
       if (hasDups(guess)) {
           print('  No digits can be duplicated.');
           continue;
       }    
       return guess;
   }

}

function hasDups(ary) {

   var t = ary.concat().sort();
   for (var i = 1; i < t.length; i++) {
       if (t[i] == t[i-1]) return true;
   }
   return false;

}

function showInstructions(len) {

   print();
   print('Bulls and Cows Game');
   print('-------------------');
   print('  You must guess the ' + len + ' digit number I am thinking of.');
   print('  The number is composed of the digits 1-9.');
   print('  No digit appears more than once.');
   print('  After each of your guesses, I will tell you:');
   print('    The number of bulls (digits in right place)');
   print('    The number of cows (correct digits, but in the wrong place)');
   print();

}

function pickNum(len) {

   var nums = [1, 2, 3, 4, 5, 6, 7, 8, 9];
   nums.sort(function(){return Math.random() - 0.5});
   return nums.slice(0, len);

}

main(); </lang>

Example game (cheating!):

Bulls and Cows Game
-------------------
  You must guess the 4 digit number I am thinking of.
  The number is composed of the digits 1-9.
  No digit appears more than once.
  After each of your guesses, I will tell you:
    The number of bulls (digits in right place)
    The number of cows (correct digits, but in wrong place)

Your guess #1: 1234
    Bulls: 0, cows: 2
Your guess #2: 5678
    Bulls: 1, cows: 1
Your guess #3: 3167
    Bulls: 0, cows: 3
Your guess #4: 9123
    Bulls: 1, cows: 1
Your guess #5: 5137
    Bulls: 1, cows: 3
Your guess #6: 5317
    Bulls: 2, cows: 2
Your guess #7: 5731
    Bulls: 2, cows: 2
Your guess #8: 5713
    Bulls: 4, cows: 0
You win! Guesses needed: 8

Julia

<lang julia>function cowsbulls() print("Welcome to Cows & Bulls! I've picked a number with unique digits between 1 and 9, go ahead and type your guess.\n You get one bull for every right number in the right position.\n You get one cow for every right number, but in the wrong position.\n Enter 'n' to pick a new number and 'q' to quit.\n>") function new_number() s = [1:9] n = "" for i = 9:-1:6 n *= string(delete!(s,rand(1:i))) end return n end answer = new_number() while true input = chomp(readline(STDIN)) input == "q" && break if input == "n" answer = new_number() print("\nI've picked a new number, go ahead and guess\n>") continue end !ismatch(r"^[1-9]{4}$",input) && (print("Invalid guess: Please enter a 4-digit number\n>"); continue) if input == answer print("\nYou're right! Good guessing!\nEnter 'n' for a new number or 'q' to quit\n>") else bulls = sum(answer.data .== input.data) cows = sum([answer[x] != input[x] && contains(input.data,answer[x]) for x = 1:4]) print("\nNot quite! Your guess is worth:\n$bulls Bulls\n$cows Cows\nPlease guess again\n\n>") end end end</lang> The following version checks thoroughly that the input of the player is constituted of four distincts digits. <lang julia>function bullsandcows ()

   bulls = cows = 0
   result = (s = {} ; while length(unique(s))<4 push!(s,rand('1':'9')) end; unique(s))
   println("A game of bulls and cows!")
   while (bulls != 4)
     print("Your guess? ")
     guess = collect(chomp(readline(STDIN)))
     if ! (length(unique(guess)) == length(guess) == 4 && all(isdigit,guess))
        println("please, enter four distincts digits") 
        continue 
     end
     bulls = sum(map(==, guess, result))
     cows = length(intersect(guess,result)) - bulls
     println("$bulls bulls and $cows cows!")
   end
   println("You win!")
 end</lang>
Output:
julia> bullsandcows()
A game of bulls and cows!
Your guess? 1234
0 bulls and 2 cows!
Your guess? 12334
please, enter four distincts digits
Your guess? 5678
1 bulls and 1 cows!
Your guess? 1111
please, enter four distincts digits
Your guess? grr
please, enter four distincts digits
Your guess? ...
please, enter four distincts digits
Your guess? 

Liberty BASIC

<lang lb>

   do while len( secret$) <4
       c$ =chr$( int( rnd( 1) *9) +49)
       if not( instr( secret$, c$)) then secret$ =secret$ +c$
   loop
   print " Secret number has been guessed....                                                                                 "; secret$
   guesses  =   0

[loop]

   print " Your guess ";
   input " "; guess$
   guesses  = guesses +1
   r$       =score$( guess$, secret$)
   bulls    =val( word$( r$, 1, ","))
   cows     =val( word$( r$, 2, ","))
   print "   Result: "; bulls; " bulls, and "; cows; " cows"
   print
   if guess$ =secret$ then
       print "  You won after "; guesses; " guesses!"
       print "  You guessed it in "; guesses
       print "  Thanks for playing!"
       wait
   end if
   goto [loop]

end ' _____________________________________________________________

function check( i$) ' check =0 if no digit repeats, else =1

   check =0
   for i =1 to 3
       for j =i +1 to 4
           if mid$( i$, i, 1) =mid$( i$, j, 1) then check =1
       next j
   next i

end function

function score$( a$, b$) ' return as a csv string the number of bulls & cows.

   bulls    = 0:  cows     = 0
   for i = 1 to 4
       c$ = mid$( a$, i, 1)
       if mid$( b$, i, 1) = c$ then
           bulls = bulls + 1
       else
           if instr( b$, c$) <>0 and instr( b$, c$) <>i then
               cows = cows + 1
           end if
       end if
   next i
   score$ =str$( bulls); ","; str$( cows)

end function

[quit] close #w end </lang>

Works with: UCB Logo

<lang logo>to ok? :n

 output (and [number? :n] [4 = count :n] [4 = count remdup :n] [not member? 0 :n])

end

to init

 do.until [make "hidden random 10000] [ok? :hidden]

end

to guess :n

 if not ok? :n [print [Bad guess! (4 unique digits, 1-9)]  stop]
 localmake "bulls 0
 localmake "cows  0
 foreach :n [cond [
   [[? = item # :hidden] make "bulls 1 + :bulls]
   [[member?  ? :hidden] make "cows  1 + :cows ]
 ]]
 (print :bulls "bulls, :cows "cows)
 if :bulls = 4 [print [You guessed it!]]

end</lang>

Lua

<lang Lua>function ShuffleArray(array)

  for i=1,#array-1 do
     local t = math.random(i, #array)
     array[i], array[t] = array[t], array[i]
  end

end

function GenerateNumber()

  local digits = {1,2,3,4,5,6,7,8,9}
  ShuffleArray(digits)
  return digits[1] * 1000 +
         digits[2] *  100 +
         digits[3] *   10 +
         digits[4]

end

function IsMalformed(input)

  local malformed = false
  if #input == 4 then
     local already_used = {}
     for i=1,4 do
        local digit = input:byte(i) - string.byte('0')
        if digit < 1 or digit > 9 or already_used[digit] then
           malformed = true
           break
        end
        already_used[digit] = true
     end
  else
     malformed = true
  end
  return malformed

end

math.randomseed(os.time()) math.randomseed(math.random(2^31-1)) -- since os.time() only returns seconds

print("\nWelcome to Bulls and Cows!") print("") print("The object of this game is to guess the random 4-digit number that the") print("computer has chosen. The number is generated using only the digits 1-9,") print("with no repeated digits. Each time you enter a guess, you will score one") print("\"bull\" for each digit in your guess that matches the corresponding digit") print("in the computer-generated number, and you will score one \"cow\" for each") print("digit in your guess that appears in the computer-generated number, but is") print("in the wrong position. Use this information to refine your guesses. When") print("you guess the correct number, you win."); print("")

quit = false

repeat

  magic_number = GenerateNumber()
  magic_string = tostring(magic_number) -- Easier to do scoring with a string
  repeat
     io.write("\nEnter your guess (or 'Q' to quit): ")
     user_input = io.read()
     if user_input == 'Q' or user_input == 'q' then
        quit = true
        break
     end
     if not IsMalformed(user_input) then
        if user_input == magic_string then
           print("YOU WIN!!!")
        else
           local bulls, cows = 0, 0
           for i=1,#user_input do
              local find_result = magic_string:find(user_input:sub(i,i))
              if find_result and find_result == i then
                 bulls = bulls + 1
              elseif find_result then
                 cows = cows + 1
              end
           end
           print(string.format("You scored %d bulls, %d cows", bulls, cows))
        end
     else
        print("Malformed input. You must enter a 4-digit number with")
        print("no repeated digits, using only the digits 1-9.")
     end
  until user_input == magic_string
  if not quit then
     io.write("\nPress <Enter> to play again or 'Q' to quit: ")
     user_input = io.read()
     if user_input == 'Q' or user_input == 'q' then
        quit = true
     end
  end
  if quit then
     print("\nGoodbye!")
  end

until quit</lang>

Mathematica

<lang Mathematica> digits=Last@FixedPointList[If[Length@Union@#==4,#,Table[Random[Integer,{1,9}],{4}]]&,{}] codes=ToCharacterCode[StringJoin[ToString/@digits]]; Module[{r,bulls,cows}, While[True, r=InputString[]; If[r===$Canceled,Break[], With[{userCodes=ToCharacterCode@r}, If[userCodes===codes,Print[r<>": You got it!"];Break[], If[Length@userCodes==Length@codes, bulls=Count[userCodes-codes,0];cows=Length@Intersection[codes,userCodes]-bulls; Print[r<>": "<>ToString[bulls]<>"bull(s), "<>ToString@cows<>"cow(s)."], Print["Guess four digits."]]]]]]] </lang> Output:

{8, 2, 6, 1}
3432: 0 bull(s), 1 cow(s).
Illegal input.
8261: You got it!

MUMPS

<lang MUMPS>BullCow New bull,cow,guess,guessed,ii,number,pos,x Set number="",x=1234567890 For ii=1:1:4 Do . Set pos=$Random($Length(x))+1 . Set number=number_$Extract(x,pos) . Set $Extract(x,pos)="" . Quit Write !,"The computer has selected a number that consists" Write !,"of four different digits." Write !!,"As you are guessing the number, ""bulls"" and ""cows""" Write !,"will be awarded: a ""bull"" for each digit that is" Write !,"placed in the correct position, and a ""cow"" for each" Write !,"digit that occurs in the number, but in a different place.",! Write !,"For a guess, enter 4 digits." Write !,"Any other input is interpreted as ""I give up"".",! Set guessed=0 For Do Quit:guessed . Write !,"Your guess: " Read guess If guess'?4n Set guessed=-1 Quit . Set (bull,cow)=0,x=guess . For ii=4:-1:1 If $Extract(x,ii)=$Extract(number,ii) Do . . Set bull=bull+1,$Extract(x,ii)="" . . Quit . For ii=1:1:$Length(x) Set:number[$Extract(x,ii) cow=cow+1 . Write !,"You guessed ",guess,". That earns you " . If 'bull,'cow Write "neither bulls nor cows..." Quit . If bull Write bull," bull" Write:bull>1 "s" . If cow Write:bull " and " Write cow," cow" Write:cow>1 "s" . Write "." . If bull=4 Set guessed=1 Write !,"That's a perfect score." . Quit If guessed<0 Write !!,"The number was ",number,".",! Quit Do BullCow

The computer has selected a number that consists of four different digits.

As you are guessing the number, "bulls" and "cows" will be awarded: a "bull" for each digit that is placed in the correct position, and a "cow" for each digit that occurs in the number, but in a different place.

For a guess, enter 4 digits. Any other input is interpreted as "I give up".

Your guess: 1234 You guessed 1234. That earns you 1 cow. Your guess: 5678 You guessed 5678. That earns you 1 cow. Your guess: 9815 You guessed 9815. That earns you 1 cow. Your guess: 9824 You guessed 9824. That earns you 2 cows. Your guess: 9037 You guessed 9037. That earns you 1 bull and 2 cows. Your guess: 9048 You guessed 2789. That earns you 1 bull and 2 cows. Your guess: 2079 You guessed 2079. That earns you 1 bull and 3 cows. Your guess: 2709 You guessed 2709. That earns you 2 bulls and 2 cows. Your guess: 0729 You guessed 0729. That earns you 4 cows. Your guess: 2907 You guessed 2907. That earns you 4 bulls. That's a perfect score.</lang>

OCaml

<lang ocaml>let rec input () =

 let s = read_line () in
 try
   if String.length s <> 4 then raise Exit;
   String.iter (function
     | '1'..'9' -> ()
     | _ -> raise Exit
   ) s;
   let t = [ s.[0]; s.[1]; s.[2]; s.[3] ] in
   let _ = List.fold_left  (* reject entry with duplication *)
             (fun ac b -> if List.mem b ac then raise Exit; (b::ac))
             [] t in
   List.map (fun c -> int_of_string (String.make 1 c)) t
 with Exit ->
   prerr_endline "That is an invalid entry. Please try again.";
   input ()

let print_score g t =

 let bull = ref 0 in
 List.iter2 (fun x y ->
   if x = y then incr bull
 ) g t;
 let cow = ref 0 in
 List.iter (fun x ->
   if List.mem x t then incr cow
 ) g;
 cow := !cow - !bull;
 Printf.printf "%d bulls, %d cows\n%!" !bull !cow

let () =

 Random.self_init ();
 let rec mkgoal acc = function 4 -> acc
 | i ->
     let n = succ(Random.int 9) in
     if List.mem n acc
     then mkgoal acc i
     else mkgoal (n::acc) (succ i)
 in
 let g = mkgoal [] 0 in
 let found = ref false in
 while not !found do
   let t = input () in
   if t = g
   then found := true
   else print_score g t
 done;
 print_endline "Congratulations you guessed correctly";
</lang>

ooRexx

The solution at Rexx Version 2 is a valid ooRexx program.

Oz

<lang oz>declare

 proc {Main}
    Solution = {PickNUnique 4 {List.number 1 9 1}}
    proc {Loop}
       Guess = {EnterGuess}
    in
       {System.showInfo
        {Bulls Guess Solution}#" bulls and "#
        {Cows Guess Solution}#" cows"}
       if Guess \= Solution then {Loop} end
    end
 in
    {Loop}
    {System.showInfo "You have won!"}
 end
 fun {Bulls Xs Sol}
    {Length {Filter {List.zip Xs Sol Value.'=='} Id}}
 end
 fun {Cows Xs Sol}
    {Length {Intersection Xs Sol}}
 end
 local
    class TextFile from Open.file Open.text end
    StdIn = {New TextFile init(name:stdin)}
 in
    fun {EnterGuess}
       try
          {System.printInfo "Enter your guess (e.g. \"1234\"): "}
          S = {StdIn getS($)}
       in
          %% verify
          {Length S} = 4
          {All S Char.isDigit} = true
          {FD.distinct S} %% assert there is no duplicate digit
          %% convert from digits to numbers
          {Map S fun {$ D} D-&0 end}
       catch _ then
          {EnterGuess}
       end
    end
 end
 fun {PickNUnique N Xs}
    {FoldL {MakeList N}
     fun {$ Z _}
        {Pick {Diff Xs Z}}|Z
     end
     nil}
 end
 fun {Pick Xs}
    {Nth Xs {OS.rand} mod {Length Xs} + 1}
 end
 fun {Diff Xs Ys}
    {FoldL Ys List.subtract Xs}
 end
 fun {Intersection Xs Ys}
    {Filter Xs fun {$ X} {Member X Ys} end}
 end
 
 fun {Id X} X end

in

 {Main}</lang>

PARI/GP

This simple implementation expects guesses in the form [a,b,c,d]. <lang parigp>bc()={

 my(u,v,bulls,cows);
 while(#vecsort(v=vector(4,i,random(9)+1),,8)<4,);
 while(bulls<4,
   u=input();
   if(type(u)!="t_VEC"|#u!=4,next);
   bulls=sum(i=1,4,u[i]==v[i]);
   cows=sum(i=1,4,sum(j=1,4,i!=j&v[i]==u[j]));
   print("You have "bulls" bulls and "cows" cows")
 )

};</lang>

Perl

<lang perl>use Data::Random qw(rand_set); use List::MoreUtils qw(uniq);

my $size = 4; my $chosen = join "", rand_set set => ["1".."9"], size => $size;

print "I've chosen a number from $size unique digits from 1 to 9; you need to input $size unique digits to guess my number\n";

for ( my $guesses = 1; ; $guesses++ ) {

   my $guess;
   while (1) {
       print "\nNext guess [$guesses]: ";
       $guess = <STDIN>;
       chomp $guess;
       checkguess($guess) and last;
       print "$size digits, no repetition, no 0... retry\n";
   }
   if ( $guess eq $chosen ) {
       print "You did it in $guesses attempts!\n";
       last;
   }
   my $bulls = 0;
   my $cows = 0;
   for my $i (0 .. $size-1) {
       if ( substr($guess, $i, 1) eq substr($chosen, $i, 1) ) {
           $bulls++;
       } elsif ( index($chosen, substr($guess, $i, 1)) >= 0 ) {
           $cows++;
       }
   }
   print "$cows cows, $bulls bulls\n";

}

sub checkguess {

   my $g = shift;
   return uniq(split //, $g) == $size && $g =~ /^[1-9]{$size}$/;

}</lang>

Perl 6

Translation of: Python
Works with: Rakudo Star version 2010-08

<lang perl6>my $size = 4; my @secret = pick $size, '1' .. '9';

for 1..* -> $guesses {

   my @guess;
   loop {
       @guess = (prompt("Guess $guesses: ") // exit).comb;
       last if @guess == $size and
           all(@guess) eq one(@guess) & any('1' .. '9');
       say 'Malformed guess; try again.';
   }
   my ($bulls, $cows) = 0, 0;
   for ^$size {
       when @guess[$_] eq @secret[$_] { ++$bulls; }
       when @guess[$_] eq any @secret { ++$cows; }
   }
   last if $bulls == $size;
   say "$bulls bulls, $cows cows.";

}

say 'A winner is you!';</lang>

PHP

<lang php><?php $size = 4;

$chosen = implode(array_rand(array_flip(range(1,9)), $size));

echo "I've chosen a number from $size unique digits from 1 to 9; you need to input $size unique digits to guess my number\n";

for ($guesses = 1; ; $guesses++) {

   while (true) {
       echo "\nNext guess [$guesses]: ";
       $guess = rtrim(fgets(STDIN));
       if (!checkguess($guess))
           echo "$size digits, no repetition, no 0... retry\n";
       else
           break;
   }
   if ($guess == $chosen) {
       echo "You did it in $guesses attempts!\n";
       break;
   } else {
       $bulls = 0;
       $cows = 0;
       foreach (range(0, $size-1) as $i) {
           if ($guess[$i] == $chosen[$i])
               $bulls++;
           else if (strpos($chosen, $guess[$i]) !== FALSE)
               $cows++;
       }
       echo "$cows cows, $bulls bulls\n";
   }

}

function checkguess($g) {

 global $size;
 return count(array_unique(str_split($g))) == $size &&
   preg_match("/^[1-9]Template:$size$/", $g);

} ?></lang>

PicoLisp

<lang lisp>(de ok? (N)

  (let D (mapcar 'format (chop N))
     (and (num? N)
          (not (member 0 D))
          (= 4 (length D))
          (= D (uniq D))
          D )) )

(de init-cows ()

  (until (setq *Hidden (ok? (rand 1234 9876)))) )

(de guess (N)

  (let D (ok? N)
     (if D
        (let Bulls (cnt '= D *Hidden)
           (if (= 4 Bulls)
              " You guessed it!"
              (let Cows (- (cnt '((N) (member N *Hidden)) D) Bulls)
                 (pack Bulls " bulls, " Cows " cows") ) ) )
        " Bad guess! (4 unique digits, 1-9)" ) ) )

</lang>

Prolog

Works with SWI-Prolog 6.1.8 (for predicate foldl), module lambda, written by Ulrich Neumerkel found there http://www.complang.tuwien.ac.at/ulrich/Prolog-inedit/lambda.pl and module clpfd written by Markus Triska. <lang Prolog>:- use_module(library(lambda)).

- use_module(library(clpfd)).

% Parameters of the server

% length of the guess proposition(4).

% Numbers of digits % 0 -> 8 digits(8).


bulls_and_cows_server :- proposition(LenGuess), length(Solution, LenGuess), choose(Solution), repeat, write('Your guess : '), read(Guess), ( study(Solution, Guess, Bulls, Cows) -> format('Bulls : ~w Cows : ~w~n', [Bulls, Cows]), Bulls = LenGuess ; digits(Digits), Max is Digits + 1, format('Guess must be of ~w digits between 1 and ~w~n', [LenGuess, Max]), fail).

choose(Solution) :- digits(Digits), Max is Digits + 1, repeat, maplist(\X^(X is random(Max) + 1), Solution), all_distinct(Solution), !.

study(Solution, Guess, Bulls, Cows) :- proposition(LenGuess), digits(Digits),

% compute the transformation 1234 => [1,2,3,4] atom_chars(Guess, Chars), maplist(\X^Y^(atom_number(X, Y)), Chars, Ms),

% check that the guess is well formed length(Ms, LenGuess), maplist(\X^(X > 0, X =< Digits+1), Ms),

% compute the digit in good place foldl(\X^Y^V0^V1^((X = Y->V1 is V0+1; V1 = V0)),Solution, Ms, 0, Bulls),

% compute the digits in bad place foldl(\Y1^V2^V3^(foldl(\X2^Z2^Z3^(X2 = Y1 -> Z3 is Z2+1; Z3 = Z2), Ms, 0, TT1), V3 is V2+ TT1), Solution, 0, TT), Cows is TT - Bulls. </lang>

PureBasic

<lang PureBasic>Define.s secret, guess, c Define.i bulls, cows, guesses, i

If OpenConsole()

 While Len(secret) < 4
   c = Chr(Random(8) + 49)
   If FindString(secret, c, 1) = 0
     secret + c
   EndIf 
 Wend
 Repeat
   Print("Guess a 4-digit number with no duplicate digits: ")
   guess = Input()
   If Len(guess) = 0 
     Break   ;break from loop
   EndIf 
 
   isMalformedGuess = #False
   If Len(guess) <> 4
     ;guess is too short
     isMalformedGuess = #True 
   Else
     For i = 1 To 4
       c = Mid(guess, i, 1)
       If Not FindString("123456789", c, 1) Or CountString(guess, c) <> 1
         ;guess contains either non-digits or duplicate digits
         isMalformedGuess = #True
         Break ;break from For/Next loop
       EndIf 
     Next
   EndIf
 
   If isMalformedGuess
     PrintN("** You should enter 4 different numeric digits that are each from 1 to 9!")
     Continue ;continue loop
   EndIf 
   
   bulls = 0: cows = 0: guesses = guesses + 1
   For i = 1 To 4
     c = Mid(secret, i, 1)
     If Mid(guess, i, 1) = c
       bulls + 1
     ElseIf FindString(guess, c, 1)
       cows + 1
     EndIf 
   Next
 
   Print( Str(bulls) + " bull")
   If bulls <> 1
     Print( "s")
   EndIf 
   Print( ", " + Str(cows) + " cow")
   If cows <> 1
     PrintN( "s")
   Else
     PrintN("")
   EndIf
 
   If guess = secret
     PrintN("You won after " + Str(guesses) + " guesses!")
     Break    ;break from loop
   EndIf
 ForEver
 Print(#CRLF$ + #CRLF$ + "Press ENTER to exit")
 Input()
 CloseConsole()

EndIf</lang>

Python

<lang python>

Bulls and cows. A game pre-dating, and similar to, Mastermind.

import random

digits = '123456789' size = 4 chosen = .join(random.sample(digits,size))

  1. print chosen # Debug

print I have chosen a number from %s unique digits from 1 to 9 arranged in a random order. You need to input a %i digit, unique digit number as a guess at what I have chosen % (size, size) guesses = 0 while True:

   guesses += 1
   while True:
       # get a good guess
       guess = raw_input('\nNext guess [%i]: ' % guesses).strip()
       if len(guess) == size and \
          all(char in digits for char in guess) \
          and len(set(guess)) == size:
           break
       print "Problem, try again. You need to enter %i unique digits from 1 to 9" % size
   if guess == chosen:
       print '\nCongratulations you guessed correctly in',guesses,'attempts'
       break
   bulls = cows = 0
   for i in range(size):
       if guess[i] == chosen[i]:
           bulls += 1
       elif guess[i] in chosen:
           cows += 1
   print '  %i Bulls\n  %i Cows' % (bulls, cows)</lang>

Sample output:

I have chosen a number from 4 unique digits from 1 to 9 arranged in a random order.
You need to input a 4 digit, unique digit number as a guess at what I have chosen

Next guess [1]: 79
Problem, try again. You need to enter 4 unique digits from 1 to 9

Next guess [1]: 7983
  2 Bulls
  2 Cows

Next guess [2]: 7938

Congratulations you guessed correctly in 2 attempts

R

Works with: R version 2.8.1

<lang R>target <- sample(1:9,4) bulls <- 0 cows <- 0 attempts <- 0 while (bulls != 4)

 {
 input <- readline("Guess a 4-digit number with no duplicate digits or 0s: ")
 if (nchar(input) == 4)
   {
   input <- as.integer(strsplit(input,"")1)
   if ((sum(is.na(input)+sum(input==0))>=1) | (length(table(input)) != 4)) {print("Malformed input!")} else {
     bulls <- sum(input == target)
     cows <- sum(input %in% target)-bulls
     cat("\n",bulls," Bull(s) and ",cows, " Cow(s)\n")
     attempts <- attempts + 1
     }
   } else {print("Malformed input!")}
 }

print(paste("You won in",attempts,"attempt(s)!"))</lang>


Racket

<lang racket>

  1. lang racket
secret
(listof exact-nonnegative-integer?)

(define secret

 (foldr (λ (n result) 
          (cons n (map (λ (y) (if (>= y n) (add1 y) y)) 
                       result)))
        '()
        (map random '(10 9 8 7))))
(count-bulls/cows guess) -> (values exact-nonnegative-integer?
exact-nonnegative-integer?)
guess
(listof exact-nonnegative-integer?)

(define (count-bulls/cows guess)

 (let* ([bulls (map = guess secret)]
        [cow-candidates (filter-map (λ (x y) (if (false? x) y #f))
                                     bulls
                                     secret)]
        [cows (filter (curryr member cow-candidates) guess)])
   (values (length (filter ((curry equal?) #t) bulls))
           (length cows))))
(valid-guess guess-str) -> (or/c (listof exact-nonnegative-integer?) #f)
guess-str
string?

(define (valid-guess guess-str)

 (define (char->digit c)
   (- (char->integer c) (char->integer #\0)))
 (if (regexp-match-exact? #px"[0-9]{4}" guess-str)
     (let ([guess (map char->digit (string->list guess-str))])
       (if (andmap (λ (x) (equal? (count ((curry equal?) x) guess) 1)) 
                   guess)
           guess
           #f))
     #f))
          
Game states

(define win #t) (define game #f)

(main-loop state step) -> void?
state
boolean?
step
exact-nonnegative-integer?

(define (main-loop state step)

 (if (equal? state win)
     (printf "You won after ~a guesses." step)
     (begin 
       (let* ([guess-str (read-line)]
              [guess (valid-guess guess-str)])
         (if (false? guess) 
             (begin (displayln "Guess should include exactly four different digits")
                    (main-loop state step))
             (let-values ([(bulls cows) (count-bulls/cows guess)])
               (if (= bulls 4)
                   (main-loop win (add1 step))
                   (begin (printf "Bulls: ~a Cows: ~a\n" bulls cows)
                          (main-loop state (add1 step))))))))))

(main-loop game 0)</lang>

Output:

1234
Bulls: 0 Cows: 1
21345
Guess should include exactly four different digits
2134
Bulls: 1 Cows: 0
2314
Bulls: 0 Cows: 1
5167
Bulls: 1 Cows: 1
5189
Bulls: 1 Cows: 2
0189
Bulls: 1 Cows: 2
8179
Bulls: 1 Cows: 3
7198
You won after 8 guesses.

REXX

Version 1

This REXX version of Bulls and Cows doesn't allow repeated digits (in the computer-generated number),
nor the use of the zero digit.

To allow a zero digit, see the comment about the random bif invocation.
To allow repeated digits in the computer-generated number, delete the REXX statement if pos(r,?).... <lang rexx>/*REXX pgm interactively plays a game of "Bulls & Cows" with CBLs. */ /* [CBLs = Carbon Based Lifeforms.] */ /* */ /* This game is also known as: Cows and Bulls */ /* Pigs and Bulls */ /* Bulls and Cleots */ /* MasterMind (or Master Mind) */ /*══════════════════════════════════════════════════════════════════════*/ ?=; do until length(?)==4 /*generate unique 4-digit number.*/

      r=random(1,9)                   /*change  1──►0  to allow a 0 dig*/
      if pos(r,?)\==0 then iterate    /*don't allow a repeated digit.  */
      ?=? || r
      end   /*until*/

prompt='[Bulls & Cows game] ', /*build the prompt text string. */

             "Please enter a 4-digit guess (with no zeroes)   [or Quit]:"
 do until bulls==4                    /*play until guessed |enters QUIT*/
 say prompt;  pull n;  n=space(n,0);  if n== then iterate
 if abbrev('QUIT',n,1) then exit      /*Does the user want to quit now?*/
 g=?;  L=length(n);  bulls=0;  cows=0
                                      /*bull count─────────────────────*/
      do j=1 for L;  if substr(n,j,1)\==substr(g,j,1)  then iterate
      bulls=bulls+1                   /*bump the bull count.           */
      g=overlay(' ',g,j)              /*disallow this for a cow count. */
      end   /*j*/
                                      /*cow  count─────────────────────*/
         do k=1 for L;  x=substr(n,k,1);   if pos(x,g)==0 then iterate
         cows=cows+1                  /*bump the cow count.            */
         g=translate(g,,x)            /*this allows for rule variants. */
         end   /*k*/
 if bulls\==4 then say "───── You got" bulls 'bull's(bulls) "and" cows 'cow's(cows)"."
 end       /*until bulls==4*/

say; say " ┌─────────────────────────────────────────┐"

      say "          │                                         │"
      say "          │  Congratulations, you've guessed it !!  │"
      say "          │                                         │"
      say "          └─────────────────────────────────────────┘";    say

exit /*──────────────────────────────────S subroutine────────────────────────*/ s: if arg(1)==1 then return ; return 's' </lang>

Version 2

<lang rexx> /*REXX program to play the game of "Bulls & Cows". *******************

  • Changes from Version 1:
  • ?= -> qq= (righthandside mandatory and I never use ? as symbol -
  • although it is available on all Rexxes)
  • implemented singular/plural distinction differently
  • change getRand to avoid invalid digit rejection
  • check user's input for multiple digits
  • add feature MM to ease guessing (MM=Mastermind - a similar game)
  • add feature ? to see the solution (for the impatient player)
  • program runs as is on ooRexx and on TSO (after changing | to !)
  • Made source and output more compact
  • formatted source 'my way' 2 July 2012 Walter Pachl
                                                                                                                                            • /

ask='<Bulls & Cows game> Please enter a four-digit guess (or QUIT):'

b.='bulls'; b.1='bull' c.='cows'; c.1='cow' qq=getRand() mm=0 Do Forever

 If get_guess()==qq Then leave
 Call scorer
 Say "You got" bulls b.bulls "and" cows c.cows"."
 If mm Then
   Say mms
 End   /*forever*/

Say " *******************************************" Say " * *" Say " * Congratulations, you've guessed it !! *" Say " * *" Say " *******************************************" Exit

get_guess: /*get a guess from the guesser. */

do forever

 Say ask
 Parse Pull guessi
 guess=translate(guessi)
 bc=verify(guess,987654321)
 Select
   When guess='?'       Then Say qq 'is the correct sequence'
   When guess='QUIT'    Then Exit
   When guess='MM'      Then Do
                             Say 'Mastermind output enabled'
                             mm=1
                             End
   When guess=        Then Call ser 'no argument specified.'
   When words(guess)>1  Then Call ser 'too many arguments specified.'
   When verify(0,guess)=0 Then Call ser 'illegal digit: 0'
   When bc>0 Then Call ser 'illegal character:' substr(guessi,bc,1)
   When length(guess)<4 Then Call ser 'not enough digits'
   When length(guess)>4 Then Call ser 'too many digits'
   When dups(guess)     Then Call ser '4 DIFFERENT digits, please'
   Otherwise Do
     /********** Say guess ************/
     Return guess
     End
   End
 End

getRand: digits='123456789' qq= Do i=1 To 4

 d=random(1,length(digits))
 d=substr(digits,d,1)
 qq=qq||d
 digits=space(translate(digits,' ',d),0)
 /************ Say qq digits ************/
 End

Return qq

scorer: g=qq mms='----' bulls=0 Do j=1 for 4

 If substr(guess,j,1)=substr(qq,j,1) Then Do
   bulls=bulls+1
   guess=overlay(' ',guess,j)
   mms=overlay('+',mms,j)
   End
 End

cows=0 Do j=1 To 4

 If pos(substr(guess,j,1),qq)>0 Then Do
   cows=cows+1
   mms=overlay('.',mms,j)
   End
 End

Return

dups: Procedure Parse Arg s Do i=1 To 3

 If pos(substr(s,i,1),substr(s,i+1))>0 Then
   Return 1
 End

Return 0

ser: Say '*** error ***' arg(1); Return </lang>

Ruby

Inspired by Tcl

Works with: Ruby version 1.8.7+

<lang ruby>def generate_word(len)

 [*"1".."9"].shuffle.first(len)        # [*"1".."9"].sample(len)  ver 1.9+

end

def get_guess(len)

 loop do
   print "Enter a guess: "
   guess = gets.strip
   err = case
         when guess.match(/[^1-9]/)             ; "digits only"
         when guess.length != len               ; "exactly #{len} digits"
         when guess.split("").uniq.length != len; "digits must be unique"
         else return guess.split("")
         end
   puts "the word must be #{len} unique digits between 1 and 9 (#{err}). Try again."
 end

end

def score(word, guess)

 bulls = cows = 0
 guess.each_with_index do |num, idx|
   if word[idx] == num
     bulls += 1
   elsif word.include? num
     cows += 1
   end
 end 
 [bulls, cows]

end

word_length = 4 puts "I have chosen a number with #{word_length} unique digits from 1 to 9." word = generate_word(word_length) count = 0 loop do

 guess = get_guess(word_length)
 count += 1
 break if word == guess
 puts "that guess has %d bulls and %d cows" % score(word, guess)

end puts "you guessed correctly in #{count} tries."</lang>

Inspired by Python

Works with: Ruby version 1.8.7+

<lang ruby>$size = 4 $secret = [*'1' .. '9'].shuffle.first $size

i=0 loop do

 i+=1
 
 loop do
   print "Guess #{i}: "
   $guess = gets.chomp.chars.to_a
   exit if $guess.empty?
   break if $guess.size == $size and 
     $guess.all? { |x| ('1'..'9').include? x } and
     $guess.uniq.size == $size
   puts "Problem, try again. You need to enter #{$size} unique digits from 1 to 9"
 end
 if $guess == $secret
   puts "Congratulations you guessed correctly in #{i} attempts"
   break
 end
 bulls = cows = 0
 $size.times do |j|
   bulls += 1 if $guess[j] == $secret[j]
   cows += 1 if $secret.include? $guess[j]
 end
 puts "Bulls: #{bulls}; Cows: #{cows}"

end</lang>

Scala

<lang scala>import scala.util.Random

object BullCow {

  def main(args: Array[String]): Unit = {
     val number=chooseNumber
     var guessed=false
     var guesses=0
     while(!guessed){
        Console.print("Guess a 4-digit number with no duplicate digits: ")
        val input=Console.readInt
        val digits=input.toString.map(_.asDigit).toList
        if(input>=1111 && input<=9999 && !hasDups(digits)){
           guesses+=1
           var bulls, cows=0
           for(i <- 0 to 3)
              if(number(i)==digits(i))
                 bulls+=1
              else if(number.contains(digits(i)))
                 cows+=1
           if(bulls==4)
              guessed=true
           else
              println("%d Cows and %d Bulls.".format(cows, bulls))
        }
     }
     println("You won after "+guesses+" guesses!");
  }
  def chooseNumber={
     var digits=List[Int]()
     while(digits.size<4){
        val d=Random.nextInt(9)+1
        if (!digits.contains(d))
           digits=digits:+d
     }
     digits
  }
  def hasDups(input:List[Int])=input.size!=input.distinct.size

}</lang>

Scheme

Works with: any R6RS Scheme

<lang scheme>

generate a random non-repeating list of 4 digits, 1-9 inclusive

(define (get-num)

 (define (gen lst)
   (if (= (length lst) 4) lst
       (let ((digit (+ (random 9) 1)))
         (if (member digit lst) ;make sure the new digit isn't in the
                                ;list
             (gen lst)
             (gen (cons digit lst))))))
 (string->list (apply string-append (map number->string (gen '())))))
is g a valid guess (that is, non-repeating, four digits 1-9
inclusive?)

(define (valid-guess? g)

 (let ((g-num (string->number (apply string g))))
   ;does the same digit appear twice in lst?
   (define (repeats? lst)
     (cond ((null? lst) #f)
           ((member (car lst) (cdr lst)) #t)
           (else (repeats? (cdr lst)))))
   (and g-num
        (> g-num 1233)
        (< g-num 9877)
        (not (repeats? g)))))
return '(cows bulls) for the given guess

(define (score answer guess)

 ;total cows + bulls
 (define (cows&bulls a g)
   (cond ((null? a) 0)
         ((member (car a) g) (+ 1 (cows&bulls (cdr a) g)))
         (else (cows&bulls (cdr a) g))))
 ;bulls only
 (define (bulls a g)
   (cond ((null? a) 0)
         ((equal? (car a) (car g)) (+ 1 (bulls (cdr a) (cdr g))))
         (else (bulls (cdr a) (cdr g)))))
 (list (- (cows&bulls answer guess) (bulls answer guess)) (bulls answer guess)))
play the game

(define (bull-cow answer)

 ;get the user's guess as a list
 (define (get-guess)
   (let ((e (read)))
     (if (number? e)
         (string->list (number->string e))
         (string->list (symbol->string e)))))
 (display "Enter a guess: ")
 (let ((guess (get-guess)))
   (if (valid-guess? guess)
       (let ((bulls (cadr (score answer guess)))
             (cows (car (score answer guess))))
         (if (= bulls 4)
             (display "You win!\n")
             (begin
               (display bulls)
               (display " bulls, ")
               (display cows)
               (display " cows.\n")
               (bull-cow answer))))
       (begin
         (display "Invalid guess.\n")
         (bull-cow answer)))))

(bull-cow (get-num)) </lang>

Sample game play

Enter a guess: 1234
0 bulls, 1 cows.
Enter a guess: 2345
1 bulls, 0 cows.
Enter a guess: 2346
1 bulls, 1 cows.
Enter a guess: 2367
0 bulls, 1 cows.
Enter a guess: 2647
1 bulls, 1 cows.
Enter a guess: 2648
2 bulls, 1 cows.
Enter a guess: 2468
1 bulls, 2 cows.
Enter a guess: 1468
1 bulls, 2 cows.
Enter a guess: 2684
0 bulls, 3 cows.
Enter a guess: 6248
3 bulls, 0 cows.
Enter a guess: 6948
You win!


Smalltalk

Works with: GNU Smalltalk

<lang smalltalk>Object subclass: BullsCows [

 |number|
 BullsCows class >> new: secretNum [ |i|
   i := self basicNew.
   (self isValid: secretNum)
      ifFalse: [ SystemExceptions.InvalidArgument
                   signalOn: secretNum
                   reason: 'You need 4 unique digits from 1 to 9' ].
   i setNumber: secretNum.
   ^ i
 ]
 BullsCows class >> new [ |b| b := Set new.
    [ b size < 4 ]
      whileTrue: [ b add: ((Random between: 1 and: 9) displayString first) ].
    ^ self new: (b asString)
 ]
 BullsCows class >> isValid: num [
   ^ (num asSet size = 4) & ((num asSet includes: $0) not)
 ]
 setNumber: num [ number := num ]
 check: guess [ |bc| bc := Bag new.
    1 to: 4 do: [ :i |
      (number at: i) = (guess at: i)
        ifTrue: [ bc add: 'bulls' ]
        ifFalse: [
            (number includes: (guess at: i))
              ifTrue: [ bc add: 'cows' ]
        ]
    ].
    ^ bc
 ]

].

'Guess the 4-digits number (digits from 1 to 9, no repetition)' displayNl.

|guessMe d r tries| [

 tries := 0.
 guessMe := BullsCows new.
 [
   [
     'Write 4 digits: ' display.
     d := stdin nextLine.
     (BullsCows isValid: d)
   ] whileFalse: [
        'Insert 4 digits, no repetition, exclude the digit 0' displayNl
   ].
   r := guessMe check: d.
   tries := tries + 1.
   (r occurrencesOf: 'bulls') = 4
 ] whileFalse: [
   ('%1 cows, %2 bulls' % { r occurrencesOf: 'cows'. r occurrencesOf: 'bulls' })
     displayNl.
 ].
 ('Good, you guessed it in %1 tries!' % { tries }) displayNl.
 'Do you want to play again? [y/n]' display.
 ( (stdin nextLine) = 'y' )

] whileTrue: [ Character nl displayNl ].</lang>

Tcl

<lang tcl>proc main {} {

   fconfigure stdout -buffering none
   set length 4
   
   puts "I have chosen a number from $length unique digits from 1 to 9 arranged in a random order.

You need to input a $length digit, unique digit number as a guess at what I have chosen

   "
   
   while true {
       set word [generateWord $length]
       set count 1
       while {[set guess [getGuess $length]] ne $word} {
           printScore $length $word $guess
           incr count
       }
       puts "You guessed correctly in $count tries."
       if {[yn "Play again?"] eq "n"} break
   }

}

proc generateWord {length} {

   set chars 123456789
   for {set i 1} {$i <= $length} {incr i} {
       set idx [expr {int(rand() * [string length $chars])}]
       append word [string index $chars $idx]
       set chars [string replace $chars $idx $idx]
   }
   return $word
   # here's another way to generate word with no duplications
   set word ""
   while {[string length $word] < $length} {
       set char [expr {int(1 + 9*rand())}]
       if {[string first $char $word] == -1} {
           append word $char
       }
   }

}

proc getGuess {length} {

   puts -nonewline "Enter your guess: "
   while true {
       gets stdin guess
       if {[string match [string repeat {[1-9]} $length] $guess]} {
           return $guess
       }
       if {[string tolower [string trim $guess]] eq "quit"} {
           puts Bye
           exit
       }
       puts "The word must be $length digits between 1 and 9 inclusive.  Try again."
   }

}

proc printScore {length word guess} {

   set bulls 0
   set cows 0
   for {set i 0} {$i < $length} {incr i} {
       if {[string index $word $i] eq [string index $guess $i]} {
           incr bulls
           set word [string replace $word $i $i +]
       }
   }
   puts "  $bulls bulls"
   for {set i 0} {$i < $length} {incr i} {
       if {[set j [string first [string index $guess $i] $word]] != -1} {
           incr cows
           set word [string replace $word $j $j -]
       }
   }
   puts "  $cows cows"

}

proc yn {msg} {

   while true {
       puts -nonewline "$msg \[y/n] "
       gets stdin ans
       set char [string tolower [string index [string trim $ans] 0]]
       if {$char eq "y" || $char eq "n"} {
           return $char
       }
   }

}

main</lang>

TUSCRIPT

<lang tuscript> $$ MODE tuscript SET nr1=RANDOM_NUMBERS (1,9,1) LOOP

 SET nr2=RANDOM_NUMBERS (1,9,1)
 IF (nr2!=nr1) EXIT

ENDLOOP LOOP

 SET nr3=RANDOM_NUMBERS (1,9,1)
 IF (nr3!=nr1,nr2) EXIT

ENDLOOP LOOP

 SET nr4=RANDOM_NUMBERS (1,9,1)
 IF (nr4!=nr1,nr2,nr3) EXIT

ENDLOOP SET nr=JOIN(nr1,"'",nr2,nr3,nr4), limit=10 LOOP r=1,limit SET bulls=cows=0 ASK "round {r} insert a number":guessnr="" SET length=LENGTH(guessnr), checknr=STRINGS (guessnr,":>/:")

LOOP n=nr,y=checknr
 IF (length!=4) THEN
  PRINT "4-letter digit required"
  EXIT
 ELSEIF (n==y) THEN
  SET bulls=bulls+1
 ELSEIF (nr.ct.":{y}:") THEN
  SET cows=cows+1
 ENDIF
ENDLOOP

PRINT "bulls=",bulls," cows=",cows

IF (bulls==4) THEN
 PRINT "BINGO"
 EXIT
ELSEIF (r==limit) THEN
 PRINT "BETTER NEXT TIME"
 EXIT
ENDIF

ENDLOOP </lang> Output:

round 1 insert a number >1234
bulls=1 cows=1
round 2 insert a number >5678
bulls=1 cows=1
round 3 insert a number >1298
bulls=2 cows=0
round 4 insert a number >2379
bulls=0 cows=0
round 5 insert a number >1468
bulls=4 cows=0
BINGO

UNIX Shell

Works with: bash version 3

<lang bash>#!/bin/bash

rand() {

 local min=${1:-0}
 local max=${2:-32767}
 [ ${min} -gt ${max} ] &&
 min=$(( min ^ max )) &&
 max=$(( min ^ max )) &&
 min=$(( min ^ max )) 
 echo -n $(( ( $RANDOM % $max ) + $min ))

}

in_arr() {

 local quandry="${1}"
 shift
 local arr=( $@ )
 local i=
 for i in ${arr[*]}
 do
   [ "${quandry}" == "${i}" ] && return 0 && break
 done
 return 1

}

delete_at() {

 local idx="$(( $1 + 1 ))"
 shift
 local arr=( "sentinel" $@ )
 echo -n "${arr[@]:1:$(( idx - 1 ))} ${arr[@]:$((idx + 1)):$(( ${#arr[@]} - idx - 1))}"

}

delete_first() {

 local meanie="${1}"
 shift
 local arr=( $@ )
 local i=0
 for (( i = 0; i < ${#arr[@]} ; i++ ))
 do
   [ "${arr[${i}]}" == "${meanie}" ] && arr=( $( delete_at ${i} ${arr[*]} ) )
 done
 echo -n "${arr[*]}"

}

to_arr() {

 local string="${1}"
 local arr=()
 while [ "${#string}" -gt 0 ]
 do
   arr=( ${arr[*]} ${string:0:1} )
   string="${string:1}"
 done
 echo -n "${arr[*]}"

}

choose_idx() {

 local arr=( $@ )
 
 echo -n "$( rand 0 $(( ${#arr[@]} - 1 )) )"

}

locate_bulls() {

 local secret=( $( to_arr "${1}" ) )
 local guess=( $( to_arr "${2}" ) )
 local hits=()
 local i=0
 for (( i=0; i<4; i++ ))
 do
   [ "${secret[${i}]}" -eq "${guess[${i}]}" ] && hits=( ${hits[*]} ${i} )
 done
 echo -n "${hits[*]}"

}

bulls() {

 local secret="${1}"
 local guess="${2}"
 local bulls=( $( locate_bulls "${secret}" "${guess}" ) )
 echo -n "${#bulls[@]}"

}

cows() {

 local secret=( $( to_arr "${1}" ) )
 local guess=( $( to_arr "${2}" ) )
 local bulls=( $( locate_bulls "${1}" "${2}" ) )
 local hits=0
 local i=
 # Avoid double-counting bulls
 for i in ${bulls[*]}
 do
   secret=( $( delete_at ${i} ${secret[*]} ) )
 done
 
 # Process the guess against what's left of the secret
 for i in ${guess[*]}
 do
   in_arr "${i}" ${secret[*]} && 
   secret=( $( delete_first "${i}" ${secret[*]} ) ) &&
   (( hits++ ))
 done
 echo -n ${hits}

}

malformed() {

 local guess=( $( to_arr "${1}" ) )
 local i=
 [ ${#guess[@]} -ne 4 ] && 
 return 0
 for i in ${guess[*]}
 do
   if ! in_arr ${i} 1 2 3 4 5 6 7 8 9 
   then
     return 0
     break
   fi
 done
 return 1

}

candidates=( 1 2 3 4 5 6 7 8 9 ) secret=

while [ "${#secret}" -lt 4 ] do

 cidx=$( choose_idx ${candidates[*]} )
 secret="${secret}${candidates[${cidx}]}"
 candidates=( $(delete_at ${cidx} ${candidates[*]} ) )

done

while read -p "Enter a four-digit guess: " guess do

 malformed "${guess}" && echo "Malformed guess" && continue
 [ "${guess}" == "${secret}" ] && echo "You win!" && exit
 echo "Score: $( bulls "${secret}" "${guess}" ) Bulls, $( cows "${secret}" "${guess}" ) Cows"

done</lang>

Vedit macro language

<lang vedit>Buf_Switch(Buf_Free)

  1. 90 = Time_Tick // seed for random number generator
  2. 91 = 10 // random numbers in range 0 to 9

while (EOB_pos < 4) { // 4 digits needed

   Call("RANDOM")
   BOF Ins_Char(Return_Value + '0')
   Replace("(.)(.*)\1", "\1\2", REGEXP+BEGIN+NOERR)  // remove any duplicate

}

  1. 3 = 0

repeat (99) {

   Get_Input(10, "Guess a 4-digit number with no duplicate digits: ", NOCR)
   if (Reg_Size(10) == 0) { Break }                // empty string = exit
   Num_Eval_Reg(10)                                // check for numeric digits
   if (Chars_Matched != 4) {
       M("You should enter 4 numeric digits\n")
       Continue
   }
   Goto_Pos(4)                                     // count bulls
   Reg_Ins(10, OVERWRITE)
   #1 = Search("(.)...\1", REGEXP+BEGIN+ALL+NOERR)
   RS(10, "[", INSERT)                             // count cows
   RS(10, "]", APPEND)
   #2 = Search_Block(@10, 0, 4, REGEXP+BEGIN+ALL+NOERR) - #1
   #3++
   NT(#1, NOCR) M(" bulls,") NT(#2, NOCR) M(" cows\n") 
   if (#1 == 4) {
       M("You won after") NT(#3, NOCR) M(" guesses!\n")
       Break
   }

} Buf_Quit(OK) Return

//-------------------------------------------------------------- // Generate random numbers in range 0 <= Return_Value < #91 // #90 = Seed (0 to 0x7fffffff) // #91 = Scaling (0 to 0x10000)

RANDOM:
  1. 92 = 0x7fffffff / 48271
  2. 93 = 0x7fffffff % 48271
  3. 90 = (48271 * (#90 % #92) - #93 * (#90 / #92)) & 0x7fffffff

Return ((#90 & 0xffff) * #91 / 0x10000)</lang>

Visual Basic .NET

<lang vbnet>Imports System Imports System.Text.RegularExpressions

Module Bulls_and_Cows

   Function CreateNumber() As String
       Dim random As New Random()
       Dim sequence As Char() = {"1"c, "2"c, "3"c, "4"c, "5"c, "6"c, "7"c, "8"c, "9"c}
       For i As Integer = 0 To sequence.Length - 1
           Dim j As Integer = random.Next(sequence.Length)
           Dim temp As Char = sequence(i) : sequence(i) = sequence(j) : sequence(j) = temp
       Next
       Return New String(sequence, 0, 4)
   End Function
   Function IsFourDigitNumber(ByVal number As String) As Boolean
       Return Regex.IsMatch(number, "^[1-9]{4}$")
   End Function
   Sub Main()
       Dim chosenNumber As String = CreateNumber()
       Dim attempt As Integer = 0
       Console.WriteLine("Number is chosen")
       Dim gameOver As Boolean = False
       Do
           attempt += 1
           Console.WriteLine("Attempt #{0}. Enter four digit number: ", attempt)
           Dim number As String = Console.ReadLine()
           Do While Not IsFourDigitNumber(number)
               Console.WriteLine("Invalid number: type four characters. Every character must digit be between '1' and '9'.")
               number = Console.ReadLine()
           Loop
           Dim bulls As Integer = 0
           Dim cows As Integer = 0
           For i As Integer = 0 To number.Length - 1
               Dim j As Integer = chosenNumber.IndexOf(number(i))
               If i = j Then
                   bulls += 1
               ElseIf j >= 0 Then
                   cows += 1
               End If
           Next
           If bulls < chosenNumber.Length Then
               Console.WriteLine("The number '{0}' has {1} bulls and {2} cows", _
                   number, bulls, cows)
           Else
               gameOver = True
           End If
       Loop Until gameOver
       Console.WriteLine("The number was guessed in {0} attempts. Congratulations!", attempt)
   End Sub

End Module</lang>