Bulls and cows: Difference between revisions
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; secret : (listof exact-nonnegative-integer?) |
; secret : (listof exact-nonnegative-integer?) |
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(define secret |
(define secret |
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(foldr (λ (n result) |
(foldr (λ (n result) |
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(cons n (map (λ (y) (if (>= y n) |
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(add1 y) |
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y)) |
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result))) |
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'() |
'() |
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(map random '(10 9 8 7)))) |
(map random '(10 9 8 7)))) |
Revision as of 04:26, 11 May 2013
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:
- The player wins if the guess is the same as the randomly chosen number, and the program ends.
- A score of one bull is accumulated for each digit in the guess that equals the corresponding digit in the randomly chosen initial number.
- 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
<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;
- 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
<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
<lang c>#include <stdio.h>
- include <stdarg.h>
- include <stdlib.h>
- include <stdbool.h>
- include <curses.h>
- include <string.h>
- define MAX_NUM_TRIES 72
- define LINE_BEGIN 7
- define LAST_LINE 18
int yp=LINE_BEGIN, xp=0;
char number[5]; char guess[5];
- 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>
- include <string>
- include <algorithm>
- 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
(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'*.
- define std'basic'*.
- define std'collections'*.
- define std'patterns'*.
- define ext'utils'*.
- define std'routines'arrays'*.
- class EDigitProp
{
#method get [ ^ self numeric - 30h. ]
}
- symbol Digits : aLiteral
= Summing &&var:List &prop:EDigitProp start:Scan::aLiteral.
- 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". ]. ]
}
- 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
<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
<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
<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$cows Cows\nPlease guess again\n\n>") end end end</lang>
Liberty BASIC
<lang lb>
do while len( secret$) <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>
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
<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))
- 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
<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 scheme>#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
<lang ruby>def generate_word(len)
([1, 2, 3, 4, 5, 6, 7, 8, 9].shuffle)[0,len].join("")
end
def get_guess(len)
while true print "Enter a guess: " guess = gets.strip err = case when guess.match(/\D/) : "digits only" when guess.length != len : "exactly #{len} digits" when guess.split("").uniq.length != len: "digits must be unique " else nil end break if err.nil? puts "the word must be #{len} unique digits between 1 and 9 (#{err}). Try again." end guess
end
def score(word, guess)
bulls = cows = 0 guess.bytes.each_with_index do |byte, idx| if word[idx] == byte bulls += 1 elsif word.include? byte cows += 1 end end [bulls, cows]
end
srand 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 while true
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>
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
<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
<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
<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}" "${guess}" ) Cows"
done</lang>
Vedit macro language
<lang vedit>Buf_Switch(Buf_Free)
- 90 = Time_Tick // seed for random number generator
- 91 = 10 // random numbers in range 0 to 9
while (EOB_pos < 4) { // 4 digits needed
Call("RANDOM") BOF Ins_Char(Return_Value + '0') Replace("(.)(.*)\1", "\1\2", REGEXP+BEGIN+NOERR) // remove any duplicate
}
- 3 = 0
repeat (99) {
Get_Input(10, "Guess a 4-digit number with no duplicate digits: ", NOCR) if (Reg_Size(10) == 0) { Break } // empty string = exit Num_Eval_Reg(10) // check for numeric digits if (Chars_Matched != 4) { M("You should enter 4 numeric digits\n") Continue }
Goto_Pos(4) // count bulls Reg_Ins(10, OVERWRITE) #1 = Search("(.)...\1", REGEXP+BEGIN+ALL+NOERR)
RS(10, "[", INSERT) // count cows RS(10, "]", APPEND) #2 = Search_Block(@10, 0, 4, REGEXP+BEGIN+ALL+NOERR) - #1
#3++ NT(#1, NOCR) M(" bulls,") NT(#2, NOCR) M(" cows\n") if (#1 == 4) { M("You won after") NT(#3, NOCR) M(" guesses!\n") Break }
} Buf_Quit(OK) Return
//-------------------------------------------------------------- // Generate random numbers in range 0 <= Return_Value < #91 // #90 = Seed (0 to 0x7fffffff) // #91 = Scaling (0 to 0x10000)
- RANDOM:
- 92 = 0x7fffffff / 48271
- 93 = 0x7fffffff % 48271
- 90 = (48271 * (#90 % #92) - #93 * (#90 / #92)) & 0x7fffffff
Return ((#90 & 0xffff) * #91 / 0x10000)</lang>
Visual Basic .NET
<lang vbnet>Imports System Imports System.Text.RegularExpressions
Module Bulls_and_Cows
Function CreateNumber() As String Dim random As New Random() Dim sequence As Char() = {"1"c, "2"c, "3"c, "4"c, "5"c, "6"c, "7"c, "8"c, "9"c}
For i As Integer = 0 To sequence.Length - 1 Dim j As Integer = random.Next(sequence.Length) Dim temp As Char = sequence(i) : sequence(i) = sequence(j) : sequence(j) = temp Next
Return New String(sequence, 0, 4) End Function
Function IsFourDigitNumber(ByVal number As String) As Boolean Return Regex.IsMatch(number, "^[1-9]{4}$") 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>
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