Penney's game
You are encouraged to solve this task according to the task description, using any language you may know.
Penney's game is a game where two players bet on being the first to see a particular sequence of heads or tails in consecutive tosses of a fair coin.
It is common to agree on a sequence length of three then one player will openly choose a sequence, for example:
Heads, Tails, Heads, or HTH for short.
The other player on seeing the first players choice will choose his sequence. The coin is tossed and the first player to see his sequence in the sequence of coin tosses wins.
- Example
One player might choose the sequence HHT and the other THT.
Successive coin tosses of HTTHT gives the win to the second player as the last three coin tosses are his sequence.
- Task
Create a program that tosses the coin, keeps score and plays Penney's game against a human opponent.
- Who chooses and shows their sequence of three should be chosen randomly.
- If going first, the computer should randomly choose its sequence of three.
- If going second, the computer should automatically play the optimum sequence.
- Successive coin tosses should be shown.
Show output of a game where the computer chooses first and a game where the user goes first here on this page.
- See also
- The Penney Ante Part 1 (Video).
- The Penney Ante Part 2 (Video).
11l
V first = random:choice([1B, 0B])
V you = ‘’
V me = ‘’
V ht = ‘HT’ // to get round ‘bug in MSVC 2017’[https://developercommunity.visualstudio.com/t/bug-with-operator-in-c/565417]
I first
me = random:sample(Array(‘HT’ * 3), 3).join(‘’)
print(‘I choose first and will win on first seeing #. in the list of tosses’.format(me))
L you.len != 3 | any(you.map(ch -> ch !C :ht)) | you == me
you = input(‘What sequence of three Heads/Tails will you win with: ’)
E
L you.len != 3 | any(you.map(ch -> ch !C :ht))
you = input(‘After you: What sequence of three Heads/Tails will you win with: ’)
me = (I you[1] == ‘T’ {‘H’} E ‘T’)‘’you[0.<2]
print(‘I win on first seeing #. in the list of tosses’.format(me))
print("Rolling:\n ", end' ‘’)
V rolled = ‘’
L
rolled ‘’= random:choice(‘HT’)
print(rolled.last, end' ‘’)
I rolled.ends_with(you)
print("\n You win!")
L.break
I rolled.ends_with(me)
print("\n I win!")
L.break
sleep(1)- Output:
I choose first and will win on first seeing THH in the list of tosses What sequence of three Heads/Tails will you win with: THT Rolling: THT You win!
Ada
-- Penney's game
-- J. Carter 2024 Jun
with Ada.Characters.Handling;
with Ada.Numerics.Discrete_Random;
with Ada.Text_IO;
procedure Penney_Game is
package Random is new Ada.Numerics.Discrete_Random (Result_Subtype => Boolean);
type Choice_List is array (1 .. 3) of Boolean;
procedure Get (List : out Choice_List);
-- Gets the player's choice
procedure Put (Bool : in Boolean);
-- Puts False => 'T', True => 'H'
procedure Put (List : in Choice_List);
-- Outputs a choice
type Optimum_Map is array (Boolean, Boolean, Boolean) of Choice_List;
Optimum : constant Optimum_Map :=
(False => (False => (False => (True, False, False), True => (True, False, False) ),
True => (False => (False, False, True), True => (False, False, True) ) ),
True => (False => (False => (True, True, False), True => (True, True, False) ),
True => (False => (False, True, True), True => (False, True, True) ) ) );
procedure Get (List : out Choice_List) is
-- Empty
begin -- Get
All_Tries : loop
Ada.Text_IO.Put (Item => "Enter your sequence as three letters, H or T: ");
One_Try : declare
Line : constant String := Ada.Characters.Handling.To_Upper (Ada.Text_IO.Get_Line);
begin -- One_Try
if Line'Length = 3 and (for all C of Line => C in 'H' |'T') then
Convert : for I in List'Range loop
List (I) := Line (I) = 'H';
end loop Convert;
return;
end if;
end One_Try;
end loop All_Tries;
end Get;
procedure Put (Bool : in Boolean) is
-- Empty
begin -- Put
Ada.Text_IO.Put (Item => (if Bool then 'H' else 'T') );
end Put;
procedure Put (List : in Choice_List) is
-- Empty
begin -- Put
Put_All : for B of List loop
Put (Bool => B);
end loop Put_All;
end Put;
Gen : Random.Generator;
Play_First : Boolean;
Comp_Choice : Choice_List;
Play_Choice : Choice_List;
Actual : Choice_List;
begin -- Penney_Game
Random.Reset (Gen => Gen);
Play_First := Random.Random (Gen);
if Play_First then
Get (List => Play_Choice);
Comp_Choice := Optimum (Play_Choice (1), Play_Choice (2), Play_Choice (3) );
else
Comp_Choice := (others => Random.Random (Gen) );
end if;
Ada.Text_IO.Put (Item => "Computer's sequence is ");
Put (List => Comp_Choice);
Ada.Text_IO.New_Line;
if not Play_First then
Get (List => Play_Choice);
end if;
Actual := (others => Random.Random (Gen) );
Put (List => Actual);
Check : loop
if Actual = Comp_Choice or Actual = Play_Choice then
Ada.Text_IO.New_Line;
Ada.Text_IO.Put_Line (Item => (if Actual = Comp_Choice then "Computer" else "Player") & " wins");
return;
end if;
Actual := Actual (2 .. 3) & Random.Random (Gen);
Put (Bool => Actual (3) );
end loop Check;
end Penney_Game;
- Output:
Computer's sequence is HTT Enter your sequence as three letters, H or T: TTH TTTTTH Player wins Enter your sequence as three letters, H or T: THH Computer's sequence is TTH TTTH Computer wins
AutoHotkey
Gui, font, s12
Gui, add, text, w90, Computer:
loop, 3
Gui, add, button, x+10 h30 w30 vCB%A_Index%
Gui, add, edit, xs w240 R3 vSequence
Gui, add, text, w90, Human:
loop, 3
Gui, add, button, x+10 h30 w30 vHB%A_Index% gHumButton, H
Gui, add, button, xm gToss, toss
Gui, add, button, x+10 gReset, Reset
Gui, show,, Penney's game
CompSeq := HumSeq := Seq := GameEnd := ""
RandomStart:
Random, WhoStarts, 1, 2
if (WhoStarts=1)
gosub, CompButton
return
;-----------------------------------------------
CompButton:
if CompSeq
return
Loop, 3
{
Random, coin, 1, 2
GuiControl,, CB%A_Index%, % coin=1?"H":"T"
CompSeq .= coin=1?"H":"T"
}
return
;-----------------------------------------------
HumButton:
if HumSeq
return
GuiControlGet, B,, % A_GuiControl
GuiControl,, % A_GuiControl, % B="H"?"T":"H"
return
;-----------------------------------------------
Toss:
if GameEnd
return
if !HumSeq
{
loop 3
{
GuiControlGet, B,, HB%A_Index%
HumSeq .= B
}
if (CompSeq = HumSeq)
{
MsgBox, 262160, Penney's game, Human's Selection Has to be different From Computer's Selection`nTry Again
HumSeq := ""
return
}
}
if !CompSeq
{
CompSeq := (SubStr(HumSeq,2,1)="H"?"T":"H") . SubStr(HumSeq,1,2)
loop, Parse, CompSeq
GuiControl,, CB%A_Index%, % A_LoopField
}
Random, coin, 1, 2
Seq .= coin=1?"H":"T"
GuiControl,, Sequence, % seq
if (SubStr(Seq, -2) = HumSeq)
MsgBox % GameEnd := "Human Wins"
else if (SubStr(Seq, -2) = CompSeq)
MsgBox % GameEnd := "Computer Wins"
return
;-----------------------------------------------
Reset:
loop, 3
{
GuiControl,, CB%A_Index%
GuiControl,, HB%A_Index%, H
}
GuiControl,, Sequence
CompSeq := HumSeq := Seq := GameEnd := ""
gosub, RandomStart
return
;-----------------------------------------------
Amazing Hopper
#include <jambo.h>
#define Getanuppercasecharinto(_X_) Getchar(_X_),Let( _X_ := Ucase(_X_) )
#define Isnotvalidin(_X_) Not( Occurs in (_X_) )
#define NOELIGEPCDESPUESDETI 0
#define ELIGEPCDESPUESDETI 1
Main
Set break
Get total args
If ( Is equal to '2' )
largo=0
Let ( largo := Get if( Argnum(2) Is less than '3', 3, Argnum(2) ) )
OTRO="S"
Cursor off
Loop
P="", C="", S="", L=0
Cls
Locate(1,1), Printnl ("***** Penney's Game *****")
If ( Geq( Rand(1), 0.5) )
Gosub ' Yo tiro ', Set 'NO ELIGE PC DESPUES DE TI',Gosub ' Tú tiras '
Else
Set 'ELIGE PC DESPUES DE TI', Gosub ' Tú tiras '
End If
// a jugar:
G="", SW=1
Loop
Let( G := Cat( G, Get if( Geq( Rand(1), 0.5), "T", "H" ) ) )
Locate( 6, 1 ), Printnl( "Tiradas: ", G )
Continue if ( Less ( Len (G) ---Backup to 'L'---, 3) )
Let ( S := Right( Sub(L, Minus one 'largo') , G) )
If ( Eq( S, P ) )
Set ("TU GANAS!!"), SW=0
Else If (Eq( S, C ) )
Set ("YO GANO!!"), SW=0
End If
Prnl
Sleep(1)
Back if( SW ) is not zero
Printnl ( Utf8("¿Otro juego? S/* ") )
Getchar(OTRO)
While( Eq (OTRO, "S") )
Cursor on
Else
Printnl("Modo de uso: hopper penny.jambo <n>\ndonde \"n\" es el largo de la secuencia")
End If
End
Subrutines
Define ' Yo tiro '
Locate(4,1), Print( "Yo elijo... " )
i=largo
Loop
Let( C := Cat( C, Get if( Geq( Rand(1), 0.5), "T", "H" ) ) )
--i
Back if (i) is positive
Printnl (C)
Return
Define ' Tú tiras, elige pc '
Locate(3,1), Printnl ( Utf8("Tú eliges...") )
i=largo, c=0
Loop
Get an uppercase char into 'c'
Continue if ( var(c) Is not valid in ("HT") )
Let( P:=Cat(P,c) )
Loccol(13), Printnl(P)
--i
Back if (i) is positive
If ( elige pc )
Let (C := P)
[2] Get from (C)
Set if( Is equal to ("H"), "T", "H" )
Cput (C)
Locate(4,1), Print( "Yo elijo... ", C )
End If
Return- Output:
$ hopper penney.jambo Modo de uso: hopper penny.jambo <n> donde "n" es el largo de la secuencia $ hopper penney.jambo 5 ***** Penney's Game ***** Tú eliges...HTHHT Yo elijo... HHHHT Tiradas: TTHTTTTHHTTHHTTHTHTHHT TU GANAS!! ¿Otro juego? S/* ***** Penney's Game ***** Tú eliges...HTHTT Yo elijo... HHHTT Tiradas: THHHHTHHHHTT YO GANO!! ¿Otro juego? S/* $
BASIC
Applesoft BASIC
100 R = RND ( - 1 * ( PEEK (78) + 256 * PEEK (79))): REM RANDOMIZE
110 DEF FN R(R) = INT ( RND (1) * R) * (3 ^ (R = 8)) + 1
120 READ P$
130 DATA HTHHHHHHTHTTTHHTHTTTHTTT
140 LET M$ = CHR$ (13)
150 PRINT "WELCOME TO PENNEY'S GAME!"M$
160 INPUT "HOW MANY ROUNDS WOULD YOU LIKE TO PLAY? ";ROUNDS%
170 PRINT M$"OK, LET'S PLAY "ROUNDS%" ROUNDS."
180 FOR COUNT = 1 TO ROUNDS%
190 PRINT M$"*** ROUND #"COUNT" ***"M$
200 ON FN R(2) GOSUB 300,400
210 PRINT "LET'S GO!"M$
220 GOSUB 450"PLAY ROUND
230 INPUT "PRESS RETURN TO GO ON...";N$
240 NEXT COUNT
250 PRINT M$"*** END RESULT ***"M$
260 IF YOU > ME THEN PRINT "CONGRATULATIONS! YOU WON!"
270 IF ME > YOU THEN PRINT "HOORAY! I WON"
280 IF ME = YOU THEN PRINT "COOL, WE TIED."
290 END
300 ME$ = MID$ (P$, FN R(8),3): REM RANDOM SEQUENCE
310 PRINT "I'LL PICK FIRST THIS TIME."M$" MY SEQUENCE IS "ME$"."
320 FOR REP = 0 TO 1 STEP 0
330 PRINT "WHAT SEQUENCE DO YOU WANT?"
340 GOSUB 590"GET YOUR SEQUENCE
350 LET REP = YOU$ < > ME$
360 IF NOT REP THEN PRINT "HEY, THAT'S MY SEQUENCE! THINK FOR YOURSELF!"
370 NEXT REP
380 PRINT YOU$", HUH? SOUNDS OK TO ME."
390 RETURN
400 PRINT "YOU PICK FIRST THIS TIME."
410 GOSUB 590"GET YOUR SEQUENCE
420 LET ME$ = MID$ ("HT",( MID$ (YOU$,2,1) = "H") + 1,1) + LEFT$ (YOU$,2)
430 PRINT "OK, SO YOU PICKED "YOU$M$M$"MY SEQUENCE WILL BE "ME$M$
440 RETURN
450 T0SSE$ = MID$ (P$, FN R(8),3): REM RANDOM SEQUENCE
460 PRINT "TOSSING THE COIN: "M$ MID$ (T0SSE$,2);
470 FOR T0SS = 0 TO 1 STEP 0
480 LET T0SSE$ = RIGHT$ (T0SSE$,2) + MID$ ("HT", FN R(2),1)
490 PRINT MID$ (T0SSE$,3);
500 IF YOU$ = T0SSE$ THEN 530"YOU WON
510 IF ME$ = T0SSE$ THEN 560"I WON
520 NEXT T0SS
530 YOU = YOU + 1
540 PRINT M$M$"CONGRATULATIONS! YOU WON THIS ROUND."M$"YOUR NEW SCORE IS "YOU"."
550 RETURN
560 ME = ME + 1
570 PRINT M$M$"YAY, I WON THIS ROUND!"M$"MY NEW SCORE IS "ME"."
580 RETURN
590 YOU$ = ""
600 PRINT "TYPE 3 LETTERS H OR T: "
610 FOR I = 1 TO 3
620 LET V$ = "HT"
630 GOSUB 670"GET VALID KEYPRESS
640 LET YOU$ = YOU$ + C$
650 NEXT I
660 LET V$ = M$ + M$
670 FOR C = 0 TO 1 STEP 0
680 GET C$
690 IF ASC (C$) > 95 THEN C$ = CHR$ ( ASC (C$) - 32)
700 LET C = C$ = LEFT$ (V$,1) OR C$ = MID$ (V$,2)
710 NEXT C
720 PRINT C$;
730 RETURN
BASIC256
global jugador, computador, secuencia
jugador = "" : computador = ""
function SecuenciaJugador(secuencia)
do
valido = TRUE
print chr(10) + "Ingresa una secuencia de 3 opciones, cada una de ellas H o T:";
input " > ", secuencia
secuencia = upper(secuencia)
if length(secuencia) <> 3 then valido = FALSE
if secuencia = computador then print "Pero no la misma que yo..."+ chr(10): valido = FALSE
if valido then
for i = 1 to 3
opcion = mid(secuencia, i, 1)
if opcion <> "H" and opcion <> "T" then valido = FALSE
next i
end if
until valido
SecuenciaJugador = secuencia
end function
function LanzamientoCPU()
secuencia = ""
computador =""
for i = 1 to 3
opcion = rand
if opcion < .5 then secuencia += "H" else secuencia += "T"
next i
LanzamientoCPU = secuencia
end function
do
cls
print "*** Penney's Game ***" + chr(10)
if rand < .5 then
print "Empiezas... ";
jugador = SecuenciaJugador(jugador)
computador = LanzamientoCPU()
if jugador = computador then computador = LanzamientoCPU()
print "Yo gano al ver "; computador; " por primera vez en la lista de lanzamientos..."
else
computador = LanzamientoCPU()
print "Elijo primero y gano al ver "; computador; " por primera vez en la lista de lanzamientos..."
jugador = SecuenciaJugador(jugador)
end if
print: print "Lanzamientos..."
secuencia = ""
winner = FALSE
do
pause 1
if rand <= .5 then
secuencia += "H"
print "H ";
else
print "T ";
secuencia += "T"
end if
if right(secuencia, 3) = jugador then print: print "¡Felicidades! ¡Ganaste!": winner = TRUE
if right(secuencia, 3) = computador then print: print "¡Yo gano!": winner = TRUE
until winner
do
valido = FALSE
print
input "¿Otra partida? (S/N) ", otra
if instr("SsNn", otra) then valido = TRUE
until valido
until upper(otra) = "N"
print "¡Gracias por jugar!"
end
Sinclair ZX81 BASIC
Works with 1k of RAM.
10 IF RND>=.5 THEN GOTO 100
20 PRINT "YOU PICK FIRST."
30 INPUT P$
40 PRINT "YOU CHOSE ";P$
50 LET C$="H"
60 IF P$(2)="H" THEN LET C$="T"
70 LET C$=C$+P$( TO 2)
80 PRINT "I CHOOSE ";C$
90 GOTO 190
100 PRINT "I PICK FIRST."
110 LET C$=""
120 FOR I=1 TO 3
130 LET C$=C$+"H"
140 IF RND>=.5 THEN LET C$(I)="T"
150 NEXT I
160 PRINT "I CHOOSE ";C$
170 INPUT P$
180 PRINT "YOU CHOSE ";P$
190 LET G$=""
200 IF RND>=.5 THEN GOTO 230
210 LET G$=G$+"H"
220 GOTO 240
230 LET G$=G$+"T"
240 PRINT AT 5,0;G$
250 IF LEN G$<3 THEN GOTO 200
260 IF G$(LEN G$-2 TO )=P$ THEN GOTO 290
270 IF G$(LEN G$-2 TO )=C$ THEN GOTO 310
280 GOTO 200
290 PRINT "YOU WIN"
300 STOP
310 PRINT "I WIN"
- Output:
YOU PICK FIRST. YOU CHOSE HTH I CHOOSE HHT HTTTHTTTTHHT I WIN
Batch File
::
::Penney's Game Task from Rosetta Code Wiki
::Batch File Implementation
::
::Please Directly Open the Batch File to play...
::
@echo off
setlocal enabledelayedexpansion
title The Penney's Game Batch File
set cpu=0&set you=0
cls
echo.
echo Penney's Game
echo Batch File Implementation
:main
set you_bet=&set cpu_bet=
echo.&echo --------------------------------------------------------&echo.
echo CPU's Score: %cpu% Your Score: %you%
echo.
<nul set /p "dummy=Heads I start, Tails you start..."
set /a startrnd=%random%%%2
set firsttoss=Tails&set func=optimal
if %startrnd%==1 (set firsttoss=Heads&set func=rndbet)
ping -n 3 localhost >nul
<nul set /p "dummy=. %firsttoss%^!"
echo.&echo.
goto %func%
:rndbet
set /a "seq1=%random%%%2","seq2=%random%%%2","seq3=%random%%%2"
set binary=%seq1%%seq2%%seq3%
set cpu_bet=%binary:1=H%
set cpu_bet=%cpu_bet:0=T%
echo I will bet first. So, my bet sequence will be %cpu_bet%.
:again1
set /p "you_bet=What will be your bet sequence? "
call :validate again1
echo.&echo So, you're feeling lucky on %you_bet%. We'll see...
goto succesivetossing
:optimal
echo Ok. You will bet first.
:again2
set /p "you_bet=What will be your bet sequence? "
call :validate again2
set seq1=%you_bet:~0,1%&set seq2=%you_bet:~1,1%
set new_seq1=T
if /i %seq2%==T set new_seq1=H
set cpu_bet=%new_seq1%%seq1%%seq2%
echo.&echo Hmm... My bet will be %cpu_bet%. We'll see who's lucky...
:succesivetossing
set toses=&set cnt=0
echo.
<nul set /p "dummy=Tosses: "
:tossloop
call :tossgen
<nul set /p dummy=%toss%
ping -n 2 localhost >nul
set /a newline=%cnt%%%60
if %newline%==59 (
echo.
<nul set /p "dummy=. "
)
if "%toses:~-3,3%"=="%cpu_bet%" goto iwin
if "%toses:~-3,3%"=="%you_bet%" goto uwin
set /a cnt+=1&goto tossloop
:tossgen
set /a rand=%random%%%2
set toss=T
if %rand%==0 set toss=H
set toses=%toses%%toss%
goto :EOF
:iwin
set /a cpu+=1&set newgame=
echo.&echo.
echo I Win^^! Better Luck Next Time...
echo.
set /p "newgame=[Type Y if U Wanna Beat Me, or Else, Exit...] "
if /i "!newgame!"=="Y" goto :main
exit
:uwin
set /a you+=1&set newgame=
echo.&echo.
echo Argh, You Win^^! ...But One Time I'll Beat You.
echo.
set /p "newgame=[Type Y for Another Game, or Else, Exit...] "
if /i "!newgame!"=="Y" goto :main
exit
:validate
echo "!you_bet!"|findstr /r /c:"^\"[hHtT][hHtT][hHtT]\"$">nul || (
echo [Invalid Input...]&echo.&goto %1
)
if /i "!you_bet!"=="%cpu_bet%" (echo [Bet something different...]&echo.&goto %1)
for %%i in ("t=T" "h=H") do set "you_bet=!you_bet:%%~i!"
goto :EOF
- Output:
Note: The outputs of tosses are 'delayed' just to make the game a little more dramatic.
Penney's Game Batch File Implementation -------------------------------------------------------- CPU's Score: 0 Your Score: 0 Heads I start, Tails you start.... Heads! I will bet first. So, my bet sequence will be THH. What will be your bet sequence? tTh So, you're feeling lucky on TTH. We'll see... Tosses: HHTHTHH I Win! Better Luck Next Time... [Type Y if U Wanna Beat Me, or Else, Exit...] y -------------------------------------------------------- CPU's Score: 1 Your Score: 0 Heads I start, Tails you start.... Tails! Ok. You will bet first. What will be your bet sequence? tHt Hmm... My bet will be TTH. We'll see who's lucky... Tosses: HTTH I Win! Better Luck Next Time... [Type Y if U Wanna Beat Me, or Else, Exit...]
BBC BASIC
REM >penney
PRINT "*** Penney's Game ***"
REPEAT
PRINT ' "Heads you pick first, tails I pick first."
PRINT "And it is... ";
WAIT 100
ht% = RND(0 - TIME) AND 1
IF ht% THEN
PRINT "heads!"
PROC_player_chooses(player$)
computer$ = FN_optimal(player$)
PRINT "I choose "; computer$; "."
ELSE
PRINT "tails!"
computer$ = FN_random
PRINT "I choose "; computer$; "."
PROC_player_chooses(player$)
ENDIF
PRINT "Starting the game..." ' SPC 5;
sequence$ = ""
winner% = FALSE
REPEAT
WAIT 100
roll% = RND AND 1
IF roll% THEN
sequence$ += "H"
PRINT "H ";
ELSE
PRINT "T ";
sequence$ += "T"
ENDIF
IF RIGHT$(sequence$, 3) = computer$ THEN
PRINT ' "I won!"
winner% = TRUE
ELSE
IF RIGHT$(sequence$, 3) = player$ THEN
PRINT ' "Congratulations! You won."
winner% = TRUE
ENDIF
ENDIF
UNTIL winner%
REPEAT
valid% = FALSE
INPUT "Another game? (Y/N) " another$
IF INSTR("YN", another$) THEN valid% = TRUE
UNTIL valid%
UNTIL another$ = "N"
PRINT "Thank you for playing!"
END
:
DEF PROC_player_chooses(RETURN sequence$)
LOCAL choice$, valid%, i%
REPEAT
valid% = TRUE
PRINT "Enter a sequence of three choices, each of them either H or T:"
INPUT "> " sequence$
IF LEN sequence$ <> 3 THEN valid% = FALSE
IF valid% THEN
FOR i% = 1 TO 3
choice$ = MID$(sequence$, i%, 1)
IF choice$ <> "H" AND choice$ <> "T" THEN valid% = FALSE
NEXT
ENDIF
UNTIL valid%
ENDPROC
:
DEF FN_random
LOCAL sequence$, choice%, i%
sequence$ = ""
FOR i% = 1 TO 3
choice% = RND AND 1
IF choice% THEN sequence$ += "H" ELSE sequence$ += "T"
NEXT
= sequence$
:
DEF FN_optimal(sequence$)
IF MID$(sequence$, 2, 1) = "H" THEN
= "T" + LEFT$(sequence$, 2)
ELSE
= "H" + LEFT$(sequence$, 2)
ENDIF
- Output:
*** Penney's Game ***
Heads you pick first, tails I pick first.
And it is... heads!
Enter a sequence of three choices, each of them either H or T:
> HTT
I choose HHT.
Starting the game...
H H H H H T
I won!
Another game? (Y/N) Y
Heads you pick first, tails I pick first.
And it is... tails!
I choose HTH.
Enter a sequence of three choices, each of them either H or T:
> HHT
Starting the game...
T T H H H H T
Congratulations! You won.
Another game? (Y/N) N
Thank you for playing!
C
This solution stores the sequences in bit-packed integers. With minor adjustments, this can be extended to allow larger sequence lengths beyond the required 3. However, the ai's algorithm for the perfect choice would need to be altered. More robust methods of input could be chosen, as scanf is generally fairly unsafe. A safer alternative would be to use something like fgets, and parse the input string ourselves.
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#define SEQLEN 3
int getseq(char *s)
{
int r = 0;
int i = 1 << (SEQLEN - 1);
while (*s && i) {
switch (*s++) {
case 'H':
case 'h':
r |= i;
break;
case 'T':
case 't':
/* 0 indicates tails, this is 0, so do nothing */
break;
default:
return -1;
}
i >>= 1;
}
return r;
}
void printseq(int seq)
{
int i;
for (i = SEQLEN - 1; i >= 0; --i)
printf("%c", seq & (1 << i) ? 'h' : 't');
}
int getuser(void)
{
int user;
char s[SEQLEN + 1];
printf("Enter your sequence of %d (h/t): ", SEQLEN);
while (1) {
/* This needs to be manually changed if SEQLEN is changed */
if (scanf("%3s", s) != 1) exit(1);
if ((user = getseq(s)) != -1) return user;
printf("Please enter only h/t characters: ");
}
}
int getai(int user)
{
int ai;
printf("Computers sequence of %d is: ", SEQLEN);
/* The ai's perfect choice will only be perfect for SEQLEN == 3 */
if (user == -1)
ai = rand() & (1 << SEQLEN) - 1;
else
ai = (user >> 1) | ((~user << 1) & (1 << SEQLEN - 1));
printseq(ai);
printf("\n");
return ai;
}
int rungame(int user, int ai)
{
/* Generate first SEQLEN flips. We only need to store the last SEQLEN
* tosses at any one time. */
int last3 = rand() & (1 << SEQLEN) - 1;
printf("Tossed sequence: ");
printseq(last3);
while (1) {
if (user == last3) {
printf("\nUser wins!\n");
return 1;
}
if (ai == last3) {
printf("\nAi wins!\n");
return 0;
}
last3 = ((last3 << 1) & (1 << SEQLEN) - 2) | (rand() & 1);
printf("%c", last3 & 1 ? 'h' : 't');
}
}
int main(void)
{
srand(time(NULL));
int playerwins = 0;
int totalgames = 0;
/* Just use ctrl-c for exit */
while (1) {
int user = -1;
int ai = -1;
printf("\n");
if (rand() & 1) {
ai = getai(user);
user = getuser();
}
else {
user = getuser();
ai = getai(user);
}
playerwins += rungame(user, ai);
totalgames++;
printf("You have won %d out of %d games\n", playerwins, totalgames);
printf("=================================\n");
}
return 0;
}
- Output:
Enter your sequence of 3 (h/t): tth Computers sequence of 3 is: htt Tossed sequence: ttth User wins! You have won 1 out of 1 games ================================= Enter your sequence of 3 (h/t): tth Computers sequence of 3 is: htt Tossed sequence: thhhthhhthhhtt Ai wins! You have won 1 out of 2 games =================================
C#
using static System.Console;
using static System.Threading.Thread;
using System;
public static class PenneysGame
{
const int pause = 500;
const int N = 3;
static Random rng = new Random();
static int Toss() => rng.Next(2);
static string AsString(this int sequence) {
string s = "";
for (int b = 0b100; b > 0; b >>= 1) {
s += (sequence & b) > 0 ? 'T' : 'H';
}
return s;
}
static int UserInput() {
while (true) {
switch (ReadKey().Key) {
case ConsoleKey.Escape: return -1;
case ConsoleKey.H: return 0;
case ConsoleKey.T: return 1;
}
Console.Write('\b');
}
}
public static void Main2() {
int yourScore = 0, myScore = 0;
while (true) {
WriteLine($"Your score: {yourScore}, My score: {myScore}");
WriteLine("Determining who goes first...");
Sleep(pause);
bool youStart = Toss() == 1;
WriteLine(youStart ? "You go first." : "I go first.");
int yourSequence = 0, mySequence = 0;
if (youStart) {
WriteLine("Choose your sequence of (H)eads and (T)ails (or press Esc to exit)");
int userChoice;
for (int i = 0; i < N; i++) {
if ((userChoice = UserInput()) < 0) return;
yourSequence = (yourSequence << 1) + userChoice;
}
mySequence = ((~yourSequence << 1) & 0b100) | (yourSequence >> 1);
} else {
for (int i = 0; i < N; i++) {
mySequence = (mySequence << 1) + Toss();
}
WriteLine("I chose " + mySequence.AsString());
do {
WriteLine("Choose your sequence of (H)eads and (T)ails (or press Esc to exit)");
int choice;
yourSequence = 0;
for (int i = 0; i < N; i++) {
if ((choice = UserInput()) < 0) return;
yourSequence = (yourSequence << 1) + choice;
}
if (yourSequence == mySequence) {
WriteLine();
WriteLine("You cannot choose the same sequence.");
}
} while (yourSequence == mySequence);
}
WriteLine();
WriteLine($"Your sequence: {yourSequence.AsString()}, My sequence: {mySequence.AsString()}");
WriteLine("Tossing...");
int sequence = 0;
for (int i = 0; i < N; i++) {
Sleep(pause);
int toss = Toss();
sequence = (sequence << 1) + toss;
Write(toss > 0 ? 'T' : 'H');
}
while (true) {
if (sequence == yourSequence) {
WriteLine();
WriteLine("You win!");
yourScore++;
break;
} else if (sequence == mySequence) {
WriteLine();
WriteLine("I win!");
myScore++;
break;
}
Sleep(pause);
int toss = Toss();
sequence = ((sequence << 1) + toss) & 0b111;
Write(toss > 0 ? 'T' : 'H');
}
WriteLine("Press a key.");
ReadKey();
Clear();
}
}
}
- Output:
Your score: 0, My score: 0 Determining who goes first... I go first. I chose HHH Choose your sequence of (H)eads and (T)ails (or press Esc to exit) thh Your sequence: THH, My sequence: HHH Tossing... HTHTHTHTTHH You win! Press a key. Your score: 2, My score: 0 Determining who goes first... You go first. Choose your sequence of (H)eads and (T)ails (or press Esc to exit) thh Your sequence: THH, My sequence: TTH Tossing... HTTTTH I win! Press a key.
C++
#include <time.h>
#include <iostream>
#include <string>
using namespace std;
class penney
{
public:
penney()
{ pW = cW = 0; }
void gameLoop()
{
string a;
while( true )
{
playerChoice = computerChoice = "";
if( rand() % 2 )
{ computer(); player(); }
else
{ player(); computer(); }
play();
cout << "[Y] to play again "; cin >> a;
if( a[0] != 'Y' && a[0] != 'y' )
{
cout << "Computer won " << cW << " times." << endl << "Player won " << pW << " times.";
break;
}
cout << endl << endl;
}
}
private:
void computer()
{
if( playerChoice.length() == 0 )
{
for( int x = 0; x < 3; x++ )
computerChoice.append( ( rand() % 2 ) ? "H" : "T", 1 );
}
else
{
computerChoice.append( playerChoice[1] == 'T' ? "H" : "T", 1 );
computerChoice += playerChoice.substr( 0, 2 );
}
cout << "Computer's sequence of three is: " << computerChoice << endl;
}
void player()
{
cout << "Enter your sequence of three (H/T) "; cin >> playerChoice;
}
void play()
{
sequence = "";
while( true )
{
sequence.append( ( rand() % 2 ) ? "H" : "T", 1 );
if( sequence.find( playerChoice ) != sequence.npos )
{
showWinner( 1 );
break;
}
else if( sequence.find( computerChoice ) != sequence.npos )
{
showWinner( 0 );
break;
}
}
}
void showWinner( int i )
{
string s;
if( i ) { s = "Player wins!"; pW++; }
else { s = "Computer wins!"; cW++; }
cout << "Tossed sequence: " << sequence << endl << s << endl << endl;
}
string playerChoice, computerChoice, sequence;
int pW, cW;
};
int main( int argc, char* argv[] )
{
srand( static_cast<unsigned>( time( NULL ) ) );
penney game; game.gameLoop();
return 0;
}
- Output:
Computer's sequence of three is: HHH Enter your sequence of three (H/T) THH Tossed sequence: TTHTTTTTTTTTTTHTHTTTHTTHTTHH Player wins! [Y] to play again y Enter your sequence of three (H/T) HTH Computer's sequence of three is: HHT Tossed sequence: THHT Computer wins! [Y] to play again
Clojure
(ns penney.core
(:gen-class))
(def heads \H)
(def tails \T)
(defn flip-coin []
(let [flip (rand-int 2)]
(if (= flip 0) heads tails)))
(defn turn [coin]
(if (= coin heads) tails heads))
(defn first-index [combo coll]
(some #(if (= (second %) combo) (first %)) coll))
(defn find-winner [h c]
(if (< h c)
(do (println "YOU WIN!\n") :human)
(do (println "COMPUTER WINS!\n") :computer)))
(defn flip-off [human comp]
(let [flips (repeatedly flip-coin)
idx-flips (map-indexed vector (partition 3 1 flips))
h (first-index (seq human) idx-flips)
c (first-index (seq comp) idx-flips)]
(println (format "Tosses: %s" (apply str (take (+ 3 (min h c)) flips))))
(find-winner h c)))
(defn valid? [combo]
(if (empty? combo) true (and (= 3 (count combo)) (every? #(or (= heads %) (= tails %)) combo))))
(defn ask-move []
(println "What sequence of 3 Heads/Tails do you choose?")
(let [input (clojure.string/upper-case (read-line))]
(if-not (valid? input) (recur) input)))
(defn optimize-against [combo]
(let [mid (nth combo 1)
comp (str (turn mid) (first combo) mid)]
(println (format "Computer chooses %s: " comp)) comp))
(defn initial-move [game]
(let [combo (apply str (repeatedly 3 flip-coin))]
(println "--------------")
(println (format "Current score | CPU: %s, You: %s" (:computer game) (:human game)))
(if (= (:first-player game) tails)
(do
(println "Computer goes first and chooses: " combo)
combo)
(println "YOU get to go first."))))
(defn play-game [game]
(let [c-move (initial-move game)
h-move (ask-move)]
(if-not (empty? h-move)
(let [winner (flip-off h-move (if (nil? c-move) (optimize-against h-move) c-move))]
(recur (assoc game winner (inc (winner game)) :first-player (flip-coin))))
(println "Thanks for playing!"))))
(defn -main [& args]
(println "Penney's Game.")
(play-game {:first-player (flip-coin)
:human 0, :computer 0}))
- Output:
Penney's Game. -------------- Current score | CPU: 0, You: 0 Computer goes first and chooses: THT What sequence of 3 Heads/Tails do you choose? tth Tosses: TTH YOU WIN! -------------- Current score | CPU: 0, You: 1 YOU get to go first. What sequence of 3 Heads/Tails do you choose? tht Computer chooses TTH: Tosses: HHHTTH COMPUTER WINS! -------------- Current score | CPU: 1, You: 1 YOU get to go first. What sequence of 3 Heads/Tails do you choose? Thanks for playing!
Common Lisp
(setf *random-state* (make-random-state t))
(defparameter *heads* #\H)
(defparameter *tails* #\T)
(defun main ()
(format t "Penney's Game~%~%")
(format t "Flipping to see who goes first ...")
(setq p2 nil)
(if (string= (flip) *heads*)
(progn (format t " I do.~%")
(setq p2 (choose-random-sequence))
(format t "I choose: ~A~%" p2))
(format t "You do.~%"))
(setq p1 nil)
(loop while (null p1) doing
(format t "Enter your three-flip sequence: ")
(setq p1 (string (read)))
(cond ((/= (length p1) 3)
(format t "Sequence must consist of three flips.~%")
(setq p1 nil))
((string= p1 p2)
(format t "Sequence must be different from mine.~%")
(setq p1 nil))
((notevery #'valid? (coerce p1 'list))
(format t "Sequence must be contain only ~A's and ~A's.~%" *heads* *tails*)
(setq p1 nil))))
(format t "You picked: ~A~%" p1)
(if (null p2)
(progn
(setq p2 (choose-optimal-sequence p1))
(format t "I choose: ~A~%" p2)))
(format t "Here we go. ~A, you win; ~A, I win.~%" p1 p2)
(format t "Flips:")
(let ((winner nil)
(flips '()))
(loop while (null winner) doing
(setq flips (cons (flip) flips))
(format t " ~A" (car flips))
(if (>= (length flips) 3)
(let ((trail (coerce (reverse (subseq flips 0 3)) 'string)))
(cond ((string= trail p1) (setq winner "You"))
((string= trail p2) (setq winner "I"))))))
(format t "~&~A win!" winner)))
(defparameter *sides* (list *heads* *tails*))
(defun flip () (nth (random 2 *random-state*) *sides*))
(defun valid? (flip) (not (null (member flip *sides*))))
(defun opposite (flip) (if (string= flip *heads*) *tails* *heads*))
(defun choose-random-sequence () (coerce (list (flip) (flip) (flip)) 'string))
(defun choose-optimal-sequence (against)
(let* ((opposed (coerce against 'list))
(middle (cadr opposed))
(my-list (list (opposite middle) (car opposed) middle)))
(coerce my-list 'string)))
(main)
- Output:
Computer player first:
Penney's Game Flipping to see who goes first ... I do. I choose: THH Enter your three-flip sequence: TTH You picked: TTH Here we go. TTH, you win; THH, I win. Flips: T T T H You win!
Human player first:
Penney's Game Flipping to see who goes first ...You do. Enter your three-flip sequence: HTT You picked: HTT I choose: HHT Here we go. HTT, you win; HHT, I win. Flips: H T T You win!
D
void main() {
import std.stdio, std.random, std.algorithm, std.string,
std.conv, std.range, core.thread;
immutable first = uniform(0, 2) == 0;
string you, me;
if (first) {
me = 3.iota.map!(_ => "HT"[uniform(0, $)]).text;
writefln("I choose first and will win on first seeing %s in the list of tosses", me);
while (you.length != 3 || you.any!(c => !c.among('H', 'T')) || you == me) {
"What sequence of three Heads/Tails will you win with: ".write;
you = readln.strip;
}
} else {
while (you.length != 3 || you.any!(c => !c.among('H', 'T'))) {
"After you: What sequence of three Heads/Tails will you win with: ".write;
you = readln.strip;
}
me = (you[1] == 'T' ? 'H' : 'T') ~ you[0 .. 2];
writefln("I win on first seeing %s in the list of tosses", me);
}
"Rolling:\n ".write;
string rolled;
while (true) {
rolled ~= "HT"[uniform(0, $)];
rolled.back.write;
if (rolled.endsWith(you))
return "\n You win!".writeln;
if (rolled.endsWith(me))
return "\n I win!".writeln;
Thread.sleep(1.seconds);
}
}
The output is the same as the Python entry.
Elixir
defmodule Penney do
@toss [:Heads, :Tails]
def game(score \\ {0,0})
def game({iwin, ywin}=score) do
IO.puts "Penney game score I : #{iwin}, You : #{ywin}"
[i, you] = @toss
coin = Enum.random(@toss)
IO.puts "#{i} I start, #{you} you start ..... #{coin}"
{myC, yC} = setup(coin)
seq = for _ <- 1..3, do: Enum.random(@toss)
IO.write Enum.join(seq, " ")
{winner, score} = loop(seq, myC, yC, score)
IO.puts "\n #{winner} win!\n"
game(score)
end
defp setup(:Heads) do
myC = Enum.shuffle(@toss) ++ [Enum.random(@toss)]
joined = Enum.join(myC, " ")
IO.puts "I chose : #{joined}"
{myC, yourChoice}
end
defp setup(:Tails) do
yC = yourChoice
myC = (@toss -- [Enum.at(yC,1)]) ++ Enum.take(yC,2)
joined = Enum.join(myC, " ")
IO.puts "I chose : #{joined}"
{myC, yC}
end
defp yourChoice do
IO.write "Enter your choice (H/T) "
choice = read([])
IO.puts "You chose: #{Enum.join(choice, " ")}"
choice
end
defp read([_,_,_]=choice), do: choice
defp read(choice) do
case IO.getn("") |> String.upcase do
"H" -> read(choice ++ [:Heads])
"T" -> read(choice ++ [:Tails])
_ -> read(choice)
end
end
defp loop(myC, myC, _, {iwin, ywin}), do: {"I", {iwin+1, ywin}}
defp loop(yC, _, yC, {iwin, ywin}), do: {"You", {iwin, ywin+1}}
defp loop(seq, myC, yC, score) do
append = Enum.random(@toss)
IO.write " #{append}"
loop(tl(seq)++[append], myC, yC, score)
end
end
Penney.game
- Output:
Penney game score I : 0, You : 0 Heads I start, Tails you start ..... Heads I chose : Tails Heads Heads Enter your choice (H/T) TTH You chose: Tails Tails Heads Heads Heads Tails Tails Tails Tails Heads You win! Penney game score I : 0, You : 1 Heads I start, Tails you start ..... Tails Enter your choice (H/T) THT You chose: Tails Heads Tails I chose : Tails Tails Heads Tails Heads Heads Heads Tails Tails Heads I win! Penney game score I : 1, You : 1 Heads I start, Tails you start ..... Tails Enter your choice (H/T)
Factor
USING: arrays ascii io kernel math prettyprint random sequences
strings ;
IN: rosetta-code.penneys-game
! Generate a random boolean.
: t|f ( -- t/f )
1 random-bits 0 = ;
! Checks whether the sequence chosen by the human is valid.
: valid-input? ( seq -- ? )
[ [ CHAR: H = ] [ CHAR: T = ] bi or ] filter length 3 = ;
! Prompt the human player for a sequence.
: input-seq ( -- seq )
"Please input a 3-long sequence of H or T (heads or tails)."
print "Example: HTH" print "> " write readln >upper >array ;
! Get the human player's input sequence with error checking.
: get-input ( -- seq )
t [ drop input-seq dup valid-input? not ] loop ;
! Add a random coin flip to a vector.
: flip-coin ( vector -- vector' )
t|f CHAR: H CHAR: T ? over push ;
! Generate a random 3-long sequence of coin flips.
: rand-seq ( -- seq )
V{ } clone 3 [ flip-coin ] times ;
! Generate the optimal sequence response to a given sequence.
: optimal ( seq1 -- seq2 )
[ second dup CHAR: H = [ CHAR: T ] [ CHAR: H ] if ]
[ first ] [ second ] tri 3array nip dup
"The computer chose " write >string write "." print ;
! Choose a random sequence for the computer and report what
! was chosen.
: computer-first ( -- seq )
"The computer picks a sequence first and chooses " write
rand-seq dup >string write "." print >array ;
! The human is prompted to choose any sequence with no
! restrictions.
: human-first ( -- seq )
"You get to go first." print get-input ;
! Forbid the player from choosing the same sequence as the
! computer.
: human-second ( cseq -- cseq hseq )
get-input [ 2dup = not ]
[ drop
"You may not choose the same sequence as the computer."
print get-input
] until ;
! Display a message introducing the game.
: welcome ( -- )
"Welcome to Penney's Game. The computer or the player" print
"will be randomly selected to choose a sequence of" print
"three coin tosses. The sequence will be shown to the" print
"opponent, and then he will choose a sequence." print nl
"Then, a coin will be flipped until the sequence" print
"matches the last three coin flips, and a winner" print
"announced." print nl ;
! Check for human victory.
: human-won? ( cseq hseq coin-flips -- ? )
3 tail* >array = nip ;
! Check for computer victory.
: computer-won? ( cseq hseq coin-flips -- ? )
3 tail* >array pick = 2nip ;
! Flip a coin until a victory is detected. Then, inform the
! player who won.
: flip-coins ( cseq hseq -- )
"Flipping coins..." print
rand-seq [ 3dup [ human-won? ] [ computer-won? ] 3bi or ]
[ flip-coin ] until dup >string print human-won?
[ "You won!" print ] [ "The computer won." print ] if ;
! Randomly choose a player to choose their sequence first.
! Then play a full round of Penney's Game.
: start-game ( -- )
welcome t|f [ human-first dup optimal swap ]
[ computer-first human-second ] if flip-coins ;
start-game
- Output:
Welcome to Penney's Game. The computer or the player will be randomly selected to choose a sequence of three coin tosses. The sequence will be shown to the opponent, and then he will choose a sequence. Then, a coin will be flipped until the sequence matches the last three coin flips, and a winner announced. You get to go first. Please input a 3-long sequence of H or T (heads or tails). Example: HTH > car Please input a 3-long sequence of H or T (heads or tails). Example: HTH > htht Please input a 3-long sequence of H or T (heads or tails). Example: HTH > tth The computer chose HTT. Flipping coins... THHTHTHTHHTHHTHHTT The computer won. Welcome to Penney's Game. The computer or the player will be randomly selected to choose a sequence of three coin tosses. The sequence will be shown to the opponent, and then he will choose a sequence. Then, a coin will be flipped until the sequence matches the last three coin flips, and a winner announced. The computer picks a sequence first and chooses HHH. Please input a 3-long sequence of H or T (heads or tails). Example: HTH > hhh You may not choose the same sequence as the computer. Please input a 3-long sequence of H or T (heads or tails). Example: HTH > hht Flipping coins... HHH The computer won.
FreeBASIC
Sub Jugador_elige(secuencia As String)
Dim As String eleccion
Dim As Byte valido, i
Do
valido = True
Print !"\nIngresa una secuencia de 3 opciones, cada una de ellas H o T:";
Input " > ", secuencia
If Len(secuencia) <> 3 Then valido = False
If valido Then
For i = 1 To 3
eleccion = Mid(Ucase(secuencia), i, 1)
If eleccion <> "H" And eleccion <> "T" Then valido = False
Next
End If
Loop Until valido
End Sub
Function Aleatorio() As String
Dim As Byte eleccion, i
Dim As String tirada
tirada = ""
For i = 1 To 3
eleccion = Rnd And 1
If eleccion Then tirada += "H" Else tirada += "T"
Next
Return tirada
End Function
Function Optima(secuencia As String) As String
If Mid(secuencia, 2, 1) = "H" Then
Optima = "T" + Left(secuencia, 2)
Else
Optima = "H" + Left(secuencia, 2)
End If
End Function
Randomize Timer
Dim As String jugador, computador, otro
Dim Shared As String secuencia
Dim As Boolean ganador, valido
Do
Cls
Color 11
Print "*** Penney's Game ***" & Chr(10)
Color 7
Print "Cara eliges primero, cruz yo elijo primero."
Print "Y es... ";
Sleep 300
Dim As Double ht: ht = Rnd(0 - Timer) And 1
If ht Then
Print "cara!"
Jugador_elige(jugador)
computador = Optima(jugador)
Print !"\nYo elijo "; computador; !".\n"
Else
Print "cruz!"
computador = Aleatorio
Print !"\nYo elijo "; computador; !".\n"
Jugador_elige(jugador)
End If
Print "Comenzando el juego ..."
secuencia = ""
ganador = False
Do
Sleep 200
Dim As Integer lanzar = Rnd And 1
If lanzar Then
secuencia += "H"
Print "H ";
Else
Print "T ";
secuencia += "T"
End If
If Right(secuencia, 3) = computador Then
Print !"\nGan‚!\n"
ganador = True
Else
If Right(secuencia, 3) = jugador Then
Print !"\nFelicidades! Ganaste.\n"
ganador = True
End If
End If
Loop Until ganador
Do
valido = False
Input "¨Otra ronda? (S/N) ", otro
If Instr("SYN", Ucase(otro)) Then valido = True
Loop Until valido
Loop Until Ucase(otro) = "N"
Print !"\nGracias por jugar!"
Sleep
End
Go
package main
import "fmt"
import "math/rand"
func main(){
var a1,a2,a3,y,match,j,k int
var inp string
y=1
for y==1{
fmt.Println("Enter your sequence:")
fmt.Scanln(&inp)
var Ai [3] int
var user [3] int
for j=0;j<3;j++{
if(inp[j]==104){
user[j]=1
}else{
user[j]=0
}
}
for k=0;k<3;k++{
Ai[k]=rand.Intn(2)
}
for user[0]==Ai[0]&&user[1]==Ai[1]&&user[2]==Ai[2]{
for k=0;k<3;k++{
Ai[k]=rand.Intn(2)
}
}
fmt.Println("You gave the sequence:")
printht(user)
fmt.Println()
fmt.Println("The computer generated sequence is:")
printht(Ai)
fmt.Println()
a1=rand.Intn(2)
a2=rand.Intn(2)
a3=rand.Intn(2)
fmt.Print("The generated sequence is:")
printh(a1)
printh(a2)
printh(a3)
match=0
for match==0{
if(matches(user,a1,a2,a3)==1){
fmt.Println()
fmt.Println("You have won!!!")
match=1
}else if(matches(Ai,a1,a2,a3)==1){
fmt.Println()
fmt.Println("You lost!! Computer wins")
match=1
}else{
a1=a2
a2=a3
a3=rand.Intn(2)
printh(a3)
}
}
fmt.Println("Do you want to continue(0/1):")
fmt.Scanln(&y)
}
}
func printht(a [3] int) int{
var i int
for i=0;i<3;i++{
if(a[i]==1){
fmt.Print("h")
}else{
fmt.Print("t")
}
}
return 1
}
func printh(a int) int{
if(a==1){
fmt.Print("h")
}else{
fmt.Print("t")
}
return 1
}
func matches(a [3] int,p int,q int,r int) int{
if(a[0]==p&&a[1]==q&&a[2]==r){
return 1
}else{
return 0
}
}
Output:
Enter your sequence: tht You gave the sequence: tht The computer generated sequence is: hhh The generated sequence is:hhtht You have won!!! Do you want to continue(0/1):
Haskell
import qualified Data.List as L
import System.IO
import System.Random
data CoinToss = H | T deriving (Read, Show, Eq)
parseToss :: String -> [CoinToss]
parseToss [] = []
parseToss (s:sx)
| s == 'h' || s == 'H' = H : parseToss sx
| s == 't' || s == 'T' = T : parseToss sx
| otherwise = parseToss sx
notToss :: CoinToss -> CoinToss
notToss H = T
notToss T = H
instance Random CoinToss where
random g = let (b, gb) = random g in (if b then H else T, gb)
randomR = undefined
prompt :: (Read a) => String -> String -> (String -> Maybe a) -> IO a
prompt msg err parse = do
putStrLn msg
line <- getLine
let ans = parse line
case ans of
Nothing -> do
putStrLn err
prompt msg err parse
Just ansB -> return ansB
showCat :: (Show a) => [a] -> String
showCat = concatMap show
data Winner = Player | CPU
-- This may never terminate.
runToss :: (RandomGen g) => [CoinToss] -> [CoinToss] -> g -> ([CoinToss], Winner)
runToss player cpu gen =
let stream = randoms gen
run ss@(s:sx)
| L.isPrefixOf player ss = player
| L.isPrefixOf cpu ss = cpu
| otherwise = s : run sx
winner = run stream
in if L.isSuffixOf player winner
then (winner, Player)
else (winner, CPU)
game :: (RandomGen g, Num a, Show a) => Bool -> a -> a -> g -> IO ()
game cpuTurn playerScore cpuScore gen = do
putStrLn $ "\nThe current score is CPU: " ++ show cpuScore
++ ", You: " ++ show playerScore
let (genA, genB) = split gen
promptPlayer check =
prompt "Pick 3 coin sides: " "Invalid input." $ \s ->
let tosses = parseToss s in
if check tosses then Just tosses else Nothing
promptCpu x = putStrLn $ "I have chosen: " ++ showCat x
(tosses, winner) <-
if cpuTurn
then do
let cpuChoice = take 3 $ randoms gen
promptCpu cpuChoice
playerChoice <- promptPlayer $ \n -> n /= cpuChoice && 3 == length n
return $ runToss playerChoice cpuChoice genA
else do
playerChoice <- promptPlayer $ \n -> 3 == length n
let cpuChoice = case playerChoice of [a,b,_] -> [notToss b, a, b]
promptCpu cpuChoice
return $ runToss playerChoice cpuChoice genA
putStrLn $ "The sequence tossed was: " ++ showCat tosses
case winner of
Player -> do
putStrLn "You win!"
game (not cpuTurn) (playerScore + 1) cpuScore genB
CPU -> do
putStrLn "I win!"
game (not cpuTurn) playerScore (cpuScore + 1) genB
main :: IO ()
main = do
hSetBuffering stdin LineBuffering
stdgen <- getStdGen
let (cpuFirst, genA) = random stdgen
game cpuFirst 0 0 genA
- Output:
The current score is CPU: 0, You: 0 Pick 3 coin sides: HTH I have chosen: HHT The sequence tossed was: TTTTTTHHT I win! The current score is CPU: 1, You: 0 I have chosen: TTT Pick 3 coin sides: HTT The sequence tossed was: HTT You win! The current score is CPU: 1, You: 1 Pick 3 coin sides:
J
Solution:
require 'format/printf numeric'
randomize '' NB. randomize seed for new session
Vals=: 'HT' NB. valid values
input=: 1!:1@<&1: NB. get input from user
prompt=: input@echo NB. prompt user for input
checkInput=: 'Choose 3 H/Ts' assert (Vals e.~ ]) , 3 = #
getUserSeq=: (] [ checkInput)@toupper@prompt
choose1st=: Vals {~ 3 ?@$ 2: NB. computer chooses 1st
choose2nd=: (0 1 1=1 0 1{])&.(Vals&i.) NB. computer chooses 2nd
playPenney=: verb define
if. ?2 do. NB. randomize first chooser
Comp=. choose1st ''
'Computer chose %s' printf <Comp
You=. getUserSeq 'Choose a sequence of three coin tosses (H/T):'
'Choose a different sequence to computer' assert You -.@-: Comp
else.
You=. getUserSeq 'Choose a sequence of three coin tosses (H/T):'
Comp=. choose2nd You
'Computer chose %s ' printf <Comp
end.
Tosses=. Vals {~ 100 ?@$ 2
Result=. (Comp,:You) {.@I.@E."1 Tosses
'Toss sequence is %s' printf < (3 + <./ Result) {. Tosses
echo ('No result';'You win!';'Computer won!') {::~ *-/ Result
)
Usage:
playPenney''
Computer chose TTT
Choose a sequence of three coin tosses (H/T):
HTT
Toss sequence is TTHHTT
You win!
playPenney''
Choose a sequence of three coin tosses (H/T):
HTT
Computer chose HHT
Toss sequence is HTHTT
You win!
Java
import java.util.*;
public class PenneysGame {
public static void main(String[] args) {
Random rand = new Random();
String compChoice = "", playerChoice;
if (rand.nextBoolean()) {
for (int i = 0; i < 3; i++)
compChoice += "HT".charAt(rand.nextInt(2));
System.out.printf("Computer chooses %s%n", compChoice);
playerChoice = prompt(compChoice);
} else {
playerChoice = prompt(compChoice);
compChoice = "T";
if (playerChoice.charAt(1) == 'T')
compChoice = "H";
compChoice += playerChoice.substring(0, 2);
System.out.printf("Computer chooses %s%n", compChoice);
}
String tossed = "";
while (true) {
tossed += "HT".charAt(rand.nextInt(2));
System.out.printf("Tossed %s%n" , tossed);
if (tossed.endsWith(playerChoice)) {
System.out.println("You win!");
break;
}
if (tossed.endsWith(compChoice)) {
System.out.println("Computer wins!");
break;
}
}
}
private static String prompt(String otherChoice) {
Scanner sc = new Scanner(System.in);
String s;
do {
System.out.print("Choose a sequence: ");
s = sc.nextLine().trim().toUpperCase();
} while (!s.matches("[HT]{3}") || s.equals(otherChoice));
return s;
}
}
Computer chooses HTH Choose a sequence: hhh Tossed H Tossed HH Tossed HHH You win! Choose a sequence: tth Computer chooses HTT Tossed H Tossed HT Tossed HTH Tossed HTHH Tossed HTHHT Tossed HTHHTT Computer wins!
Julia
Functions
const SLEN = 3
autobet() = randbool(SLEN)
function autobet(ob::BitArray{1})
rlen = length(ob)
2 < rlen || return ~ob
3 < rlen || return [~ob[2], ob[1:2]]
opt = falses(rlen)
opt[1] = true
opt[end-1:end] = true
ob != opt || return ~opt
return opt
end
autobet(ob::Array{Bool,1}) = autobet(convert(BitArray{1}, ob))
function pgencode{T<:String}(a::T)
b = uppercase(a)
0 < length(b) || return trues(0)
!ismatch(r"[^HT]+", b) || error(@sprintf "%s is not a HT sequence" a)
b = split(b, "")
b .== "H"
end
pgdecode(a::BitArray{1}) = join([i ? "H" : "T" for i in a], "")
function humanbet()
b = ""
while length(b) != SLEN || ismatch(r"[^HT]+", b)
print("Your bet? ")
b = uppercase(chomp(readline()))
end
return b
end
Game Setup
println("Playing Penney's Game Against the computer.")
if randbool()
mach = autobet()
println(@sprintf "The computer bet first, chosing %s." pgdecode(mach))
println("Now you can bet.")
human = pgencode(humanbet())
else
println("You bet first.")
human = pgencode(humanbet())
mach = autobet(human)
end
print(@sprintf "You bet %s " pgdecode(human))
println(@sprintf "and the computer bet %s." pgdecode(mach))
Game Play
pg = randbool(SLEN)
pgtail = copy(pg)
while pgtail != mach && pgtail != human
push!(pg, randbool())
pgtail = [pgtail[2:end], pg[end]]
end
println(@sprintf("This game lasted %d turns yielding\n %s",
length(pg), pgdecode(pg)))
if human == mach
println("so you and the computer tied.")
elseif pgtail == mach
println("so the computer won.")
else
println("so you won.")
end
- Output:
$ julia penneys_game.jl
Playing Penney's Game Against the computer.
You bet first.
Your bet? tht
You bet THT and the computer bet TTH.
This game lasted 10 turns yielding
HHTTTTTTTH
so the computer won.
$ julia penneys_game.jl
Playing Penney's Game Against the computer.
You bet first.
Your bet? hhh
You bet HHH and the computer bet THH.
This game lasted 8 turns yielding
TTHTHTHH
so the computer won.
$ julia penneys_game.jl
Playing Penney's Game Against the computer.
The computer bet first, chosing HTT.
Now you can bet.
Your bet? hht
You bet HHT and the computer bet HTT.
This game lasted 6 turns yielding
TTHHHT
so you won.
$ julia penneys_game.jl
Playing Penney's Game Against the computer.
The computer bet first, chosing HTT.
Now you can bet.
Your bet? hht
You bet HHT and the computer bet HTT.
This game lasted 6 turns yielding
THTHHT
so you won.
$ julia penneys_game.jl
Playing Penney's Game Against the computer.
You bet first.
Your bet? htt
You bet HTT and the computer bet HHT.
This game lasted 10 turns yielding
TTTTHHHHHT
so the computer won.
Kotlin
// version 1.2.10
import java.util.Random
val rand = Random()
val optimum = mapOf(
"HHH" to "THH", "HHT" to "THH", "HTH" to "HHT", "HTT" to "HHT",
"THH" to "TTH", "THT" to "TTH", "TTH" to "HTT", "TTT" to "HTT"
)
fun getUserSequence(): String {
println("A sequence of three H or T should be entered")
var userSeq: String
do {
print("Enter your sequence: ")
userSeq = readLine()!!.toUpperCase()
}
while (userSeq.length != 3 || userSeq.any { it != 'H' && it != 'T' })
return userSeq
}
fun getComputerSequence(userSeq: String = ""): String {
val compSeq = if(userSeq == "")
String(CharArray(3) { if (rand.nextInt(2) == 0) 'T' else 'H' })
else
optimum[userSeq]!!
println("Computer's sequence: $compSeq")
return compSeq
}
fun main(args: Array<String>) {
var userSeq: String
var compSeq: String
val r = rand.nextInt(2)
if (r == 0) {
println("You go first")
userSeq = getUserSequence()
println()
compSeq = getComputerSequence(userSeq)
}
else {
println("Computer goes first")
compSeq = getComputerSequence()
println()
userSeq = getUserSequence()
}
println()
val coins = StringBuilder()
while (true) {
val coin = if (rand.nextInt(2) == 0) 'H' else 'T'
coins.append(coin)
println("Coins flipped: $coins")
val len = coins.length
if (len >= 3) {
val seq = coins.substring(len - 3, len)
if (seq == userSeq) {
println("\nYou win!")
return
}
else if (seq == compSeq) {
println("\nComputer wins!")
return
}
}
Thread.sleep(2000) // wait two seconds for next flip
}
}
Sample game where computer goes first:
Computer goes first Computer's sequence: HTT A sequence of three H or T should be entered Enter your sequence: HHT Coins flipped: H Coins flipped: HH Coins flipped: HHT You win!
Sample game where user goes first:
You go first A sequence of three H or T should be entered Enter your sequence: HTH Computer's sequence: HHT Coins flipped: T Coins flipped: TT Coins flipped: TTT Coins flipped: TTTT Coins flipped: TTTTH Coins flipped: TTTTHT Coins flipped: TTTTHTH You win!
Lua
function penny_game()
local player, computer = "", ""
function player_choose()
io.write( "Enter your sequence of three H and/or T: " )
local t = io.read():upper()
if #t > 3 then t = t:sub( 1, 3 )
elseif #t < 3 then return ""
end
for i = 1, 3 do
c = t:sub( i, i )
if c ~= "T" and c ~= "H" then
print( "Just H's and T's!" )
return ""
end
end
return t
end
function computer_choose()
local t = ""
if #player > 0 then
if player:sub( 2, 2 ) == "T" then
t = "H"
else
t = "T";
end
t = t .. player:sub( 1, 2 )
else
for i = 1, 3 do
if math.random( 2 ) == 1 then
t = t .. "H"
else
t = t .. "T"
end
end
end
return t
end
if math.random( 2 ) == 1 then
computer = computer_choose()
io.write( "My sequence is: " .. computer .. "\n" )
while( true ) do
player = player_choose()
if player:len() == 3 then break end
end
else
while( true ) do
player = player_choose()
if player:len() == 3 then break end
end
computer = computer_choose()
io.write( "My sequence is: " .. computer .. "\n" )
end
local coin, i = "", 1
while( true ) do
if math.random( 2 ) == 1 then
coin = coin .. "T"
io.write( "T" )
else
coin = coin .. "H"
io.write( "H" )
end
if #coin > 2 then
local seq = coin:sub( i, i + 2 )
i = i + 1
if seq == player then
print( "\nPlayer WINS!!!" )
return 1
elseif seq == computer then
print( "\nComputer WINS!!!" )
return -1
end
end
end
end
math.randomseed( os.time() )
local cpu, user = 0, 0
repeat
r = penny_game()
if r > 0 then
user = user + 1
else
cpu = cpu + 1
end
print( "Player: " .. user .. " CPU: " .. cpu )
io.write( "Play again (Y/N)? " )
r = io.read()
until( r == "N" or r == "n" )
- Output:
>lua -e "io.stdout:setvbuf 'no'" "penny.lua" My sequence is: TTH Enter your sequence of three H and/or T: HHT TTTTH Computer WINS!!! Player: 0 CPU: 1 Play again (Y/N)? y Enter your sequence of three H and/or T: HTH My sequence is: HHT THTTHTH Player WINS!!! Player: 1 CPU: 1 Play again (Y/N)? y My sequence is: HHH Enter your sequence of three H and/or T: TTH HTTHHTH Player WINS!!! Player: 2 CPU: 1 Play again (Y/N)? n >Exit code: 0
MiniScript
randomTorH = function()
if rnd < 0.5 then return "T" else return "H"
end function
if rnd < 0.5 then
playerSeq = input("Input your sequence (e.g. HTH): ").upper
if playerSeq[1] == "T" then compSeq = "H" else compSeq = "T"
compSeq = compSeq + playerSeq[:2]
print "I choose: " + compSeq
else
compSeq = randomTorH + randomTorH + randomTorH
print "I choose: " + compSeq
playerSeq = input("Input your sequence (e.g. HTH): ").upper
end if
print "Here we go..."
seq = ""
while true
flip = randomTorH
print flip
seq = seq + flip
if seq[-3:] == playerSeq then
print "You win!"
break
else if seq[-3:] == compSeq then
print "I win!"
break
end if
wait
end while
- Output:
Input your sequence (e.g. HTH): HTH I choose: HHT Here we go... T H T H You win!
I choose: TTH Input your sequence (e.g. HTH): THH Here we go... H T T T T H I win!
Nim
import os, random, sequtils, strutils
randomize()
let first = sample([false, true])
var you, me = ""
if first:
me = newSeqWith(3, sample("HT")).join()
echo "I choose first and will win on first seeing $# in the list of tosses." % me
while you.len != 3 or not allCharsInSet(you, {'H', 'T'}) or you == me:
stdout.write "What sequence of three Heads/Tails will you win with? "
you = stdin.readLine()
else:
while you.len != 3 or not allCharsInSet(you, {'H', 'T'}):
echo "After you: what sequence of three Heads/Tails will you win with? "
you = stdin.readLine()
me = (if you[1] == 'T': 'H' else: 'T') & you[0..1]
echo "I win on first seeing $# in the list of tosses" % me
var rolled = ""
stdout.write "Rolling:\n "
while true:
rolled.add sample("HT")
stdout.write rolled[^1]
stdout.flushFile()
if rolled.endsWith(you):
echo "\n You win!"
break
elif rolled.endsWith(me):
echo "\n I win!"
break
sleep(1000)
- Output:
After you: what sequence of three Heads/Tails will you win with? HTH I win on first seeing HHT in the list of tosses Rolling: TTHTTTTHHT I win!
Pascal
PROGRAM Penney;
TYPE
CoinToss = (heads, tails);
Sequence = array [1..3] of CoinToss;
Player = record
bet: Sequence;
score: integer;
end;
VAR
Human, Computer: Player;
Rounds, Count: integer;
Function TossCoin: CoinToss;
{ Returns heads or tails at random }
Begin
if random(2) = 1 then TossCoin := Heads
else TossCoin := tails
End;
Procedure PutToss(toss: CoinToss);
{ Outputs heads or tails as a letter }
Begin
if toss = heads then write('H')
else write('T')
End;
Function GetToss: CoinToss;
{ Reads H or T from the keyboard in either lettercase }
var c: char;
Begin
{ Keep reading characters until we get an appropriate letter }
repeat read(c) until c in ['H', 'h', 'T', 't'];
{ Interpret the letter }
if c in ['H', 'h'] then GetToss := heads
else GetToss := tails
End;
Procedure ShowSequence(tosses: Sequence);
{ Outputs three coin tosses at once }
Var
i: integer;
Begin
for i := 1 to 3 do PutToss(tosses[i])
End;
Procedure ReadSequence(var tosses: Sequence);
{ Accepts three coin tosses from the keyboard }
Var i: integer;
Begin
{ Get the 3 letters }
for i := 1 to 3 do tosses[i] := GetToss;
{ Ignore the rest of the line }
readln
End;
Function Optimum(opponent: Sequence): Sequence;
{ Generates the optimum sequence against an opponent }
Begin
case opponent[2] of
heads: Optimum[1] := tails;
tails: Optimum[1] := heads
end;
Optimum[2] := opponent[1];
Optimum[3] := opponent[2]
End;
Function RandomSequence: Sequence;
{ Generates three random coin tosses }
Var
i: integer;
Begin
for i := 1 to 3 do RandomSequence[i] := TossCoin
End;
Function Match(first, second: Sequence): Boolean;
{ Detects whether a sequence of tosses matches another }
Var
different: boolean;
i: integer;
Begin
different := false;
i := 1;
while (i <= 3) and not different do begin
if not (first[i] = second[i]) then different := true;
i := i + 1
end;
Match := not different
End;
Procedure PlayRound(var human, computer: Player);
{ Shows coin tosses and announces the winner }
Var
{ We only ever need to store the 3 most recent tosses in memory. }
tosses: Sequence;
Begin
{ Start with the first three tosses }
write('Tossing the coin: ');
tosses := RandomSequence;
ShowSequence(tosses);
{ Keep tossing the coin until there is a winner. }
while not (Match(human.bet, tosses) or Match(computer.bet, tosses)) do begin
tosses[1] := tosses[2];
tosses[2] := tosses[3];
tosses[3] := TossCoin;
PutToss(tosses[3])
end;
{ Update the winner's score and announce the winner }
writeln;
writeln;
if Match(human.bet, tosses) then begin
writeln('Congratulations! You won this round.');
human.score := human.score + 1;
writeln('Your new score is ', human.score, '.')
end
else begin
writeln('Yay, I won this round!');
computer.score := computer.score + 1;
writeln('My new score is ', computer.score, '.')
end
End;
{ Main Algorithm }
BEGIN
{ Welcome the player }
writeln('Welcome to Penney''s game!');
writeln;
write('How many rounds would you like to play? ');
readln(Rounds);
writeln;
writeln('Ok, let''s play ', Rounds, ' rounds.');
{ Start the game }
randomize;
Human.score := 0;
Computer.score := 0;
for Count := 1 to Rounds do begin
writeln;
writeln('*** Round #', Count, ' ***');
writeln;
{ Choose someone randomly to pick the first sequence }
if TossCoin = heads then begin
write('I''ll pick first this time.');
Computer.bet := RandomSequence;
write(' My sequence is ');
ShowSequence(Computer.bet);
writeln('.');
repeat
write('What sequence do you want? ');
ReadSequence(Human.bet);
if Match(Human.bet, Computer.bet) then
writeln('Hey, that''s my sequence! Think for yourself!')
until not Match(Human.bet, Computer.bet);
ShowSequence(Human.bet);
writeln(', huh? Sounds ok to me.')
end
else begin
write('You pick first this time. Enter 3 letters H or T: ');
ReadSequence(Human.bet);
Computer.bet := Optimum(Human.bet);
write('Ok, so you picked ');
ShowSequence(Human.bet);
writeln;
write('My sequence will be ');
ShowSequence(Computer.bet);
writeln
end;
{ Then we can actually play the round }
writeln('Let''s go!');
writeln;
PlayRound(Human, Computer);
writeln;
writeln('Press ENTER to go on...');
readln
end;
{ All the rounds are finished; time to decide who won }
writeln;
writeln('*** End Result ***');
writeln;
if Human.score > Computer.score then writeln('Congratulations! You won!')
else if Computer.score > Human.score then writeln('Hooray! I won')
else writeln('Cool, we tied.');
writeln;
writeln('Press ENTER to finish.');
readln
END.
- Output:
Welcome to Penney's game! How many rounds would you like to play? 3 Ok, let's play 3 rounds. *** Round #1 *** I'll pick first this time. My sequence is TTH. What sequence do you want? H tt HTT, huh? Sounds ok to me. Let's go! Tossing the coin: HHHHTHHHHHHTHHHHTHHTHTHTT Congratulations! You won this round. Your new score is 1. Press ENTER to go on... *** Round #2 *** I'll pick first this time. My sequence is THT. What sequence do you want? tth TTH, huh? Sounds ok to me. Let's go! Tossing the coin: THT Yay, I won this round! My new score is 1. Press ENTER to go on... *** Round #3 *** You pick first this time. Enter 3 letters H or T: h t h Ok, so you picked HTH My sequence will be HHT Let's go! Tossing the coin: HHT Yay, I won this round! My new score is 2. Press ENTER to go on... *** End Result *** Hooray! I won Press ENTER to finish.
Perl
#!usr/bin/perl
use 5.020;
use strict;
use warnings;
#Choose who goes first
binaryRand() == 0 ? flipCoin(userFirst()) : flipCoin(compFirst());
#Return a randomly generated 1 or 0
sub binaryRand
{
return int(rand(2));
}
#Converts 1's and 0's to H's and T's, respectively.
sub convert
{
my $randNum = binaryRand();
if($randNum == 0)
{
return "T"
}
else
{
return "H";
}
}
#Prompts for and returns a user's sequence of 3
sub uSeq
{
print("Please enter a sequence of 3 of \"H\" and \"T\". EG: HHT\n>");
my $uString = <STDIN>;
while(1)
{
#Make it uppercase and validate input
chomp($uString);
$uString = uc $uString;
#Check length and content (H's and T's only!)
if(length $uString == 3 && (substr($uString, 0, 1) =~ /[HT]/ &&
substr($uString, 1, 1) =~ /[HT]/ &&
substr($uString, 2, 1) =~ /[HT]/))
{
last;
}
else
{
print("Error, try again. \n");
print("Please enter a sequence of 3 of \"H\" and \"T\". EG: HHT\n");
$uString = <STDIN>;
}
}
return $uString;
}
#Returns an array with two elements: [0] user's seq, [1] random computer seq.
sub compFirst
{
my $cSeq;
#Randomly draw a sequence of 3
for(my $i = 0; $i < 3; $i++)
{
$cSeq = $cSeq . convert();
}
print("The computer guesses first:\ncomp- $cSeq\n");
my $uSeq = uSeq();
print("user- $uSeq\n");
my @seqArr = ($uSeq, $cSeq);
return @seqArr;
}
#Returns an array with two elements: [0] user's seq, [1] optimal computer seq.
sub userFirst
{
print("The user quesses first:\n");
my $uSeq = uSeq();
my $cSeq;
#Generate the optimal sequence based on $uSeq
my $middle = substr($uSeq, 1, 1);
$middle eq "H" ? $cSeq = "T" : $cSeq = "H";
$cSeq = $cSeq . substr($uSeq, 0, 2);
print("user- $uSeq\ncomp- $cSeq\n");
my @seqArr = ($uSeq, $cSeq);
return @seqArr;
}
#Flips a coin, checking both sequences against the contents of the given array
sub flipCoin
{
my ($uSeq, $cSeq) = @_;
my $coin;
while(1)
{
$coin = $coin . convert();
if($coin =~ m/$uSeq/)
{
print("The sequence of tosses was: $coin\n");
say("The player wins! ");
last;
}
elsif($coin =~ m/$cSeq/)
{
print("The sequence of tosses was: $coin\n");
say("The computer wins! ");
last;
}
}
}
- Output:
The computer guesses first: comp- HHH Please enter a sequence of 3 of "H" and "T". EG: HHT >thh user- THH The sequence of tosses was: HTTHTTHTHTHTTTHTTTHH The player wins! ================================================ The user quesses first: Please enter a sequence of 3 of "H" and "T". EG: HHT >hht user- HHT comp- HHH The sequence of tosses was: THHH The computer wins!
Phix
Robert's robot's name is Robort.
function trio(integer pick)
return substitute_all(sprintf("%03b",pick),"10","HT")
end function
function getuser(integer bot)
integer user
while 1 do
user = 8 -- (a bit that clears after 3 shifts)
printf(1,"Enter your sequence of 3 (H/T):");
while user>7 do
integer c = upper(wait_key())
if c=#1B then abort(0) end if -- (Escape)
if find(c,"HT") then
puts(1,c)
user = and_bits(user*2+(c='H'),0b111111)
end if
end while
if user!=bot then exit end if
printf(1,"\nYou may not pick the same as Robort!\n")
end while
printf(1,"\n")
return user
end function
function getbot(int user)
int bot = iff(user=-1?rand(8)-1
:4-and_bits(user,2)*2+floor(user/2))
printf(1,"Robort picks %s\n", {trio(bot)})
return bot
end function
function rungame(integer user, bot)
/* We only need to store the last 3 tosses, as 0..7 */
int last3 = rand(8)-1
printf(1,"Rolling: %s",{trio(last3)})
while 1 do
if user=last3 then
printf(1,"\nUser wins!\n")
return 1
elsif bot=last3 then
printf(1,"\nRobort wins!\n")
return 0
end if
last3 = and_bits(last3,3)*2+(rand(2)=1)
printf(1,"%c", iff(and_bits(last3,1) ? 'H' : 'T'))
sleep(0.5)
end while
end function
procedure main()
integer playerwins = 0,
totalgames = 0,
robortwins = 0
/* Just use ctrl-c or Escape to exit */
while 1 do
integer user = -1,
bot = -1
printf(1,"\n")
if rand(2)=1 then
bot = getbot(-1)
user = getuser(bot)
else
user = getuser(-1)
bot = getbot(user)
end if
playerwins += rungame(user, bot)
totalgames += 1
robortwins = totalgames-playerwins
printf(1,"Robort:%d You:%d out of %d games\n",
{robortwins, playerwins, totalgames})
printf(1,"==================================\n")
end while
end procedure
main()
- Output:
Robort picks TTT Enter your sequence of 3 (H/T):TTT You may not pick the same as Robort! Enter your sequence of 3 (H/T):HHH Rolling: HTTT Robort wins! Robort:1 You:0 out of 1 games ================================== Enter your sequence of 3 (H/T):HTH Robort picks HHT Rolling: THTTTHHHHHHT Robort wins! Robort:2 You:0 out of 2 games ================================== Enter your sequence of 3 (H/T):TTH Robort picks HTT Rolling: THTT Robort wins! Robort:3 You:0 out of 3 games ================================== Enter your sequence of 3 (H/T):HTH Robort picks HHT Rolling: TTHHHHHHT Robort wins! Robort:4 You:0 out of 4 games ================================== Enter your sequence of 3 (H/T):HHT Robort picks THH Rolling: TTHH Robort wins! Robort:5 You:0 out of 5 games ================================== Enter your sequence of 3 (H/T):THH Robort picks TTH Rolling: THH User wins! Robort:5 You:1 out of 6 games ==================================
PicoLisp
(seed (in "/dev/urandom" (rd 8)))
(setq *S (list 0 0))
(de toss (N)
(make
(do N
(link (if (rand T) "T" "H")) ) ) )
(de comp (A Lst)
(or
(for ((I . L) Lst (cddr L) (cdr L))
(T (fully = A L) I) )
T ) )
(de score NIL
(prinl)
(prinl "Total score:")
(prinl "^Iuser: " (car *S))
(prinl "^Icomp: " (cadr *S)) )
(de play NIL
(let (C (toss 3) Lst (toss (rand 5 12)) U)
(prinl)
(prin "Select toss: ")
(setq U (in NIL (skip) (line)))
(prinl "Comp toss: " C)
(prinl "Toss: " Lst)
(setq @ (comp U Lst) @@ (comp C Lst) )
(cond
((< @ @@) (prinl "User win.") (inc *S))
((> @ @@) (prinl "Comp win.") (inc (cdr *S)))
(T (prinl "Draw, lets play again.")) )
(score) ) )
(de go NIL
(loop
(play)
(T
(prog
(prinl)
(prin "Want play again? Y/N: ")
(= "N" (uppc (in NIL (char)))) ) ) ) )
(go)- Output:
Select toss: HTH
Comp toss: THT
Toss: HHTHTTHT
User win.
Total score:
user: 1
comp: 0
Want play again? Y/N: y
Select toss: HHH
Comp toss: HTH
Toss: THHHTTHTHHH
User win.
Total score:
user: 2
comp: 0
Want play again? Y/N: y
Select toss: TTT
Comp toss: THH
Toss: TTHTTHHHHTH
Comp win.
Total score:
user: 2
comp: 1
Want play again? Y/N: n
Prolog
play :- rand1(R), game(R).
game(h) :-
format('Your turn first!~n'), player_move(P),
response(P,C), format('I am choosing '), maplist(writec, C), nl,
rand3(R), maplist(writec,R),
roll(P, C, R).
game(t) :-
rand3(C),
format('I am choosing '), maplist(writec, C), nl,
player_move(P),
rand3(R), maplist(writec, R),
roll(P, C, R).
player_move([P1,P2,P3]) :-
read_line_to_codes(user_input,Codes),
maplist(char_code,[P1,P2,P3],Codes).
roll(P, _, P) :- format('~nYou Win!~n'), !.
roll(_, C, C) :- format('~nI Win!~n'), !.
roll(P, C, [_,A,B]) :-
rand1(R),
coin_s(R,S),
write(S),
roll(P,C,[A,B,R]).
response([A,B,_], [C,A,B]) :- opp(A,C).
writec(A) :- coin_s(A,A1), write(A1).
rand1(R) :- random(V), round(V,I), coin(I,R).
rand3([R1,R2,R3]) :- rand1(R1), rand1(R2), rand1(R3).
coin(0,h). coin(1,t).
coin_s(h, 'H'). coin_s(t, 'T').
opp(h, t). opp(t, h).
Output:
?- play. I am choosing HTT |: tth HHTHHHHHHHHTHHHHTHTHTHTHTHHTT I Win! true. ?- play. Your turn first! |: hht I am choosing THH TTHTHH I Win!
Python
from __future__ import print_function
import random
from time import sleep
first = random.choice([True, False])
you = ''
if first:
me = ''.join(random.sample('HT'*3, 3))
print('I choose first and will win on first seeing {} in the list of tosses'.format(me))
while len(you) != 3 or any(ch not in 'HT' for ch in you) or you == me:
you = input('What sequence of three Heads/Tails will you win with: ')
else:
while len(you) != 3 or any(ch not in 'HT' for ch in you):
you = input('After you: What sequence of three Heads/Tails will you win with: ')
me = ('H' if you[1] == 'T' else 'T') + you[:2]
print('I win on first seeing {} in the list of tosses'.format(me))
print('Rolling:\n ', end='')
rolled = ''
while True:
rolled += random.choice('HT')
print(rolled[-1], end='')
if rolled.endswith(you):
print('\n You win!')
break
if rolled.endswith(me):
print('\n I win!')
break
sleep(1) # For dramatic effect
- Output:
>>> After you: What sequence of three Heads/Tails will you win with: TTH I win on first seeing HTT in the list of tosses Rolling: THHTHHTT I win! >>> ================================ RESTART ================================ >>> I choose first and will win on first seeing HHT in the list of tosses What sequence of three Heads/Tails will you win with: THH Rolling: HTHTHTTTHTTTTTTHH You win! >>>
Quackery
[ 2 random iff char H else char T ] is flip ( --> c )
[ 3 times flip join join ] is randstart ( --> $ )
[ -1 split drop
dup -1 peek
char T = iff char H else char T
swap join ] is beststart ( $ --> $ )
[ stack ] is playergoal ( --> s )
[ stack ] is computergoal ( --> s )
[ say "This is Penney's game."
cr cr
say "We each guess a different "
say "sequence of three coin "
say "flips."
cr
say "I will releatedly flip "
say "a coin until one of the "
say "sequences happens."
cr
say "The winner is the one who "
say "guesses the sequence that "
say "happens first."
cr cr
say "Please enter your sequence "
say "carefully as there is no "
say "error checking."
cr
say 'For example, for "heads '
say 'tails heads" type "HTH".'
cr cr ] is intro ( --> )
[ intro
randomise
flip char H = iff
[ say "I start. My guess is: "
randstart dup echo$
computergoal put
cr
$ "Please enter your guess: "
input playergoal put ]
else
[ say "You start. "
$ "Please enter your guess: "
input dup playergoal put
beststart dup
say "I guess: " echo$
computergoal put
cr ]
cr
$ ""
[ flip join
dup -3 split nip dup
computergoal share = iff
[ drop say "I win." ] done
playergoal share = iff
[ say "You win." ] done
again ]
cr
say "The complete sequence was: "
echo$ cr
computergoal release
playergoal release ] is play ( --> )- Output:
As a dialogue in the Quackery shell (REPL).
/O> play ... This is Penney's game. We each guess a different sequence of three coin flips. I will releatedly flip a coin until one of the sequences happens. The winner is the one who guesses the sequence that happens first. Please enter your sequence carefully as there is no error checking. For example, for "heads tails heads" type "HTH". You start. Please enter your guess: HTH I guess: HHT You win. The complete sequence was: TTHTH Stack empty. /O> play ... This is Penney's game. We each guess a different sequence of three coin flips. I will releatedly flip a coin until one of the sequences happens. The winner is the one who guesses the sequence that happens first. Please enter your sequence carefully as there is no error checking. For example, for "heads tails heads" type "HTH". I start. My guess is: HTT Please enter your guess: HHT You win. The complete sequence was: HTHTHHHT Stack empty. /O>
R
#===============================================================
# Penney's Game Task from Rosetta Code Wiki
# R implementation
#===============================================================
penneysgame <- function() {
#---------------------------------------------------------------
# Who goes first?
#---------------------------------------------------------------
first <- sample(c("PC", "Human"), 1)
#---------------------------------------------------------------
# Determine the sequences
#---------------------------------------------------------------
if (first == "PC") { # PC goes first
pc.seq <- sample(c("H", "T"), 3, replace = TRUE)
cat(paste("\nI choose first and will win on first seeing", paste(pc.seq, collapse = ""), "in the list of tosses.\n\n"))
human.seq <- readline("What sequence of three Heads/Tails will you win with: ")
human.seq <- unlist(strsplit(human.seq, ""))
} else if (first == "Human") { # Player goest first
cat(paste("\nYou can choose your winning sequence first.\n\n"))
human.seq <- readline("What sequence of three Heads/Tails will you win with: ")
human.seq <- unlist(strsplit(human.seq, "")) # Split the string into characters
pc.seq <- c(human.seq[2], human.seq[1:2]) # Append second element at the start
pc.seq[1] <- ifelse(pc.seq[1] == "H", "T", "H") # Switch first element to get the optimal guess
cat(paste("\nI win on first seeing", paste(pc.seq, collapse = ""), "in the list of tosses.\n"))
}
#---------------------------------------------------------------
# Start throwing the coin
#---------------------------------------------------------------
cat("\nThrowing:\n")
ran.seq <- NULL
while(TRUE) {
ran.seq <- c(ran.seq, sample(c("H", "T"), 1)) # Add a new coin throw to the vector of throws
cat("\n", paste(ran.seq, sep = "", collapse = "")) # Print the sequence thrown so far
if (length(ran.seq) >= 3 && all(tail(ran.seq, 3) == pc.seq)) {
cat("\n\nI win!\n")
break
}
if (length(ran.seq) >= 3 && all(tail(ran.seq, 3) == human.seq)) {
cat("\n\nYou win!\n")
break
}
Sys.sleep(0.5) # Pause for 0.5 seconds
}
}
- Output:
Human first.
You can choose your winning sequence first. What sequence of three Heads/Tails will you win with: THH I win on first seeing TTH in the list of tosses. Throwing: T TT TTT TTTH I win!
PC first
I choose first and will win on first seeing THH in the list of tosses. What sequence of three Heads/Tails will you win with: TTH Throwing: T TH THT THTT THTTH You win!
Racket
This does what's required of it from the task... just don't input anything outside the alphabet "htHT" for the human move.
#lang racket
;; Penney's Game. Tim Brown 2014-10-15
(define (flip . _) (match (random 2) (0 "H") (1 "T")))
(define (get-human-sequence) ; no sanity checking here!
(display "choose your winning sequence of 3 H or T > ")
(drop-right (drop (string-split (string-upcase (read-line)) "") 1) 1))
(define flips->string (curryr string-join "."))
(define (game-on p1 p2)
(printf "~a chooses: ~a. ~a chooses: ~a~%"
(car p1) (flips->string (cdr p1)) (car p2) (flips->string (cdr p2)))
(match-define (list (list name.1 p1.1 p1.2 p1.3) (list name.2 p2.1 p2.2 p2.3)) (list p1 p2))
(let turn ((seq null))
(match seq
[(list-rest (== p1.3) (== p1.2) (== p1.1) _) name.1]
[(list-rest (== p2.3) (== p2.2) (== p2.1) _) name.2]
[else
(let* ((flp (flip)) (seq+ (cons flp else)))
(printf "new-flip: ~a -> ~a~%" flp (flips->string (reverse seq+))) (turn seq+))])))
(define (play-game)
(define-values
(player-1 player-2)
(match (flip)
["H" (printf "Human chooses first: ")
(define p1 (cons 'Hom-Sap (get-human-sequence)))
(values p1 (cons 'Computer
(match p1
[(list _ f1 (and f2 (app (match-lambda ("H" "T") ("T" "H")) ¬f2)) _)
(list ¬f2 f1 f2)])))]
["T" (printf "Computer chooses first. ")
(define p1 (cons 'Computer (build-list 3 flip)))
(printf "~a chooses: ~a~%" (car p1) (flips->string (cdr p1)))
(values p1 (cons 'Hom-Sap (get-human-sequence)))]))
(printf "~a wins!~%" (game-on player-1 player-2)))
- Output:
Homo Sapiens Plays First (and wins!)
> (play-game) Human chooses first: choose your winning sequence of 3 H or T > hth Hom-Sap chooses: H.T.H. Computer chooses: H.H.T new-flip: H -> H new-flip: T -> H.T new-flip: H -> H.T.H Hom-Sap wins!
The Computer Plays First (and loses!)
> (play-game) Computer chooses first. Computer chooses: T.T.T choose your winning sequence of 3 H or T > htt Computer chooses: T.T.T. Hom-Sap chooses: H.T.T new-flip: H -> H new-flip: H -> H.H new-flip: H -> H.H.H new-flip: T -> H.H.H.T new-flip: H -> H.H.H.T.H new-flip: T -> H.H.H.T.H.T new-flip: H -> H.H.H.T.H.T.H new-flip: T -> H.H.H.T.H.T.H.T new-flip: H -> H.H.H.T.H.T.H.T.H new-flip: T -> H.H.H.T.H.T.H.T.H.T new-flip: T -> H.H.H.T.H.T.H.T.H.T.T Hom-Sap wins!
(Nail-biting stuff!)
Raku
(formerly Perl 6)
enum Coin <Heads Tails>;
enum Yay <Yay Good Super Hah Ooh Yipee Sweet Cool Yes Haha>;
enum Boo <Drat Darn Crumb Oops Rats Bah Criminy Argh Shards>;
enum Bozo «'Dude' 'Cha' 'Bzzt' 'Hey' 'Silly dilly' 'Say what!?' 'You numbskull'»;
sub flipping {
for 1..4 {
print "-\b"; sleep .1;
print "\\\b"; sleep .1;
print "|\b"; sleep .1;
print "/\b"; sleep .1;
}
}
sub your-choice($p is copy) {
loop (my @seq; @seq != 3; $p = "{Bozo.pick}! Please pick exactly 3: ") {
@seq = prompt($p).uc.comb(/ H | T /).map: {
when 'H' { Heads }
when 'T' { Tails }
}
}
@seq;
}
repeat until prompt("Wanna play again? ").lc ~~ /^n/ {
my $mefirst = Coin.roll;
print tc "$mefirst I start, {Coin(+!$mefirst).lc} you start, flipping...\n\t";
flipping;
say my $flip = Coin.roll;
my @yours;
my @mine;
if $flip == $mefirst {
print "{Yay.pick}! I get to choose first, and I choose: "; sleep 2; say @mine = |Coin.roll(3);
@yours = your-choice("Now you gotta choose: ");
while @yours eqv @mine {
say "{Bozo.pick}! We'd both win at the same time if you pick that!";
@yours = your-choice("Pick something different from me: ");
}
say "So, you'll win if we see: ", @yours;
}
else {
@yours = your-choice("{Boo.pick}! First you choose: ");
say "OK, you'll win if we see: ", @yours;
print "In that case, I'll just randomly choose: "; sleep 2; say @mine = Coin(+!@yours[1]), |@yours[0,1];
}
sub check($a,$b,$c) {
given [$a,$b,$c] {
when @mine { say "\n{Yay.pick}, I win, and you lose!"; Nil }
when @yours { say "\n{Boo.pick}, you win, but I'll beat you next time!"; Nil }
default { Coin.roll }
}
}
sleep 1;
say < OK! Ready? Right... So... Yo!>.pick;
sleep .5;
say ("Pay attention now!",
"Watch closely!",
"Let's do it...",
"You feeling lucky?",
"No way you gonna win this...",
"Can I borrow that coin again?").pick;
sleep 1;
print "Here we go!\n\t";
for |Coin.roll(3), &check ...^ :!defined {
flipping;
print "$_ ";
}
}
- Output:
Note: the actual run displays a little coin-flipping animation, but that won't show up here:
Heads I start, tails you start, flipping... Heads Yipee! I get to choose first, and I choose: Heads Heads Tails Now you gotta choose: tth So, you'll win if we see: Tails Tails Heads Yo! Can I borrow that coin again? Here we go! Tails Tails Tails Tails Tails Heads Argh, you win, but I'll beat you next time! Wanna play again? y Tails I start, heads you start, flipping... Tails Yes! I get to choose first, and I choose: Heads Tails Tails Now you gotta choose: H T T Dude! We'd both win at the same time if you pick that! Pick something different from me: heads tails tails Silly dilly! We'd both win at the same time if you pick that! Pick something different from me: h,h,h So, you'll win if we see: Heads Heads Heads OK! You feeling lucky? Here we go! Tails Tails Tails Heads Heads Heads Drat, you win, but I'll beat you next time! Wanna play again? y Heads I start, tails you start, flipping... Tails Shards! First you choose: tht OK, you'll win if we see: Tails Heads Tails In that case, I'll just randomly choose: Tails Tails Heads Right... Pay attention now! Here we go! Heads Tails Tails Heads Hah, I win, and you lose! Wanna play again? n
REXX
The REXX program keeps a running score (number of wins out of so many games played) as well as
allowing the human to pick the number (length) of the coin toss sequence.
A fair amount of code was added to ensure a valid response from the human player as well as give an informative error message.
The human player is allowed to spell out the H or T (as heads or tails).
A feature also added was to allow a seed for the random BIF to allow repeatability for a game.
/*REXX program plays/simulates Penney's Game, a two─player coin toss sequence game. */
__= copies('─', 9) /*literal for eye─catching fence. */
signal on halt /*a clean way out if CLBF quits. */
parse arg # seed . /*obtain optional arguments from the CL*/
if #=='' | #=="," then #= 3 /*Not specified? Then use the default.*/
if datatype(seed,'W') then call random ,,seed /*use seed for RANDOM #s repeatability.*/
wins=0; do games=1 /*simulate a number of Penney's games. */
call game /*simulate a single inning of a game. */
end /*games*/ /*keep at it until QUIT or halt. */
exit /*stick a fork in it, we're all done. */
/*──────────────────────────────────────────────────────────────────────────────────────*/
halt: say; say __ "Penney's Game was halted."; say; exit 13
r: arg ,$; do arg(1); $=$ || random(100, 9991) // 2; end; return $
s: if arg(1)==1 then return arg(3); return word(arg(2) 's',1) /*pluralizer.*/
/*──────────────────────────────────────────────────────────────────────────────────────*/
game: @.=; tosses=@. /*the coin toss sequence so far. */
toss1= r(1) /*result: 0=computer, 1=CBLF.*/
if \toss1 then call randComp /*maybe let the computer go first*/
if toss1 then say __ "You win the first toss, so you pick your sequence first."
else say __ "The computer won first toss, the pick was: " @.comp
call prompter /*get the human's guess from C.L.*/
call randComp /*get computer's guess if needed.*/
/*CBLF: carbon-based life form. */
say __ " your pick:" @.CBLF /*echo human's pick to terminal. */
say __ "computer's pick:" @.comp /* " comp.'s " " " */
say /* [↓] flip the coin 'til a win.*/
do flips=1 until pos(@.CBLF, tosses)\==0 | pos(@.comp, tosses)\==0
tosses= tosses || translate( r(1), 'HT', 10)
end /*flips*/ /* [↑] this is a flipping coin,*/
/* [↓] series of tosses*/
say __ "The tossed coin series was: " tosses
say
@@@="won this toss with " flips ' coin tosses.'
if pos(@.CBLF,tosses)\==0 then do; say __ "You" @@@; wins=wins+1; end
else say __ "The computer" @@@
_=wins; if _==0 then _='no'
say __ "You've won" _ "game"s(wins) 'out of ' games"."
say; say copies('╩╦', 79 % 2)'╩'; say
return
/*──────────────────────────────────────────────────────────────────────────────────────*/
prompter: oops= __ 'Oops! '; a= /*define some handy REXX literals*/
@a_z= 'ABCDEFG-IJKLMNOPQRS+UVWXYZ' /*the extraneous alphabetic chars*/
p=__ 'Pick a sequence of' # "coin tosses of H or T (Heads or Tails) or Quit:"
do until ok; say; say p; pull a /*uppercase the answer. */
if abbrev('QUIT', a, 1) then exit 1 /*the human wants to quit. */
a= space( translate(a,,@a_z',./\;:_'), 0) /*elide extraneous characters. */
b= translate(a, 10, 'HT'); L= length(a) /*translate ───► bin; get length.*/
ok= 0 /*the response is OK (so far). */
select /*verify the user response. */
when \datatype(b, 'B') then say oops "Illegal response."
when \datatype(a, 'M') then say oops "Illegal characters in response."
when L==0 then say oops "No choice was given."
when L<# then say oops "Not enough coin choices."
when L># then say oops "Too many coin choices."
when a==@.comp then say oops "You can't choose the computer's" ,
"choice: " @.comp
otherwise ok= 1
end /*select*/
end /*until ok*/
@.CBLF= a; @.CBLF!= b /*we have the human's guess now. */
return
/*──────────────────────────────────────────────────────────────────────────────────────*/
randComp: if @.comp\=='' then return /*the computer already has a pick*/
_= @.CBLF! /* [↓] use best-choice algorithm.*/
if _\=='' then g= left((\substr(_, min(2, #), 1))left(_, 1)substr(_, 3), #)
do until g\==@.CBLF!; g= r(#); end /*otherwise, generate a choice. */
@.comp= translate(g, 'HT', 10)
return
- output of a six-game session (ended by user entering a quit):
───────── The computer won first toss, the pick was: HHH ───────── Pick a sequence of 3 coin tosses of H or T (Heads or Tails) or Quit: tail tail tails ◄■■■■■■■■■■■ human's input ───────── your pick: TTT ───────── computer's pick: HHH ───────── The computer won this toss with 12 coin tosses. ───────── The tossed coin series was: HHTTHHTHTHHH ───────── You've won no games out of 1. ╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩ ───────── You win the first toss, so you pick your sequence first. ───────── Pick a sequence of 3 coin tosses of H or T (Heads or Tails) or Quit: h, h, t ◄■■■■■■■■■■■ human's input ───────── your pick: HHT ───────── computer's pick: THT ───────── The computer won this toss with 5 coin tosses. ───────── The tossed coin series was: TTTHT ───────── You've won no games out of 2. ╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩ ───────── The computer won first toss, the pick was: HHT ───────── Pick a sequence of 3 coin tosses of H or T (Heads or Tails) or Quit: heads heads heads ◄■■■■■■■■■■■ human's input ───────── your pick: HHH ───────── computer's pick: HHT ───────── The computer won this toss with 3 coin tosses. ───────── The tossed coin series was: HHT ───────── You've won no games out of 3. ╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩ ───────── The computer won first toss, the pick was: HTH ───────── Pick a sequence of 3 coin tosses of H or T (Heads or Tails) or Quit: t t h ◄■■■■■■■■■■■ human's input ───────── your pick: TTH ───────── computer's pick: HTH ───────── You won this toss with 3 coin tosses. ───────── The tossed coin series was: TTH ───────── You've won 1 game out of 4. ╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩ ───────── You win the first toss, so you pick your sequence first. ───────── Pick a sequence of 3 coin tosses of H or T (Heads or Tails) or Quit: t,h,h ◄■■■■■■■■■■■ human's input ───────── your pick: THH ───────── computer's pick: HTH ───────── You won this toss with 4 coin tosses. ───────── The tossed coin series was: TTHH ───────── You've won 2 games out of 5. ╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩ ───────── The computer won first toss, the pick was: TTH ───────── Pick a sequence of 3 coin tosses of H or T (Heads or Tails) or Quit: tth ◄■■■■■■■■■■■ human's input ───────── Oops! You can't choose the computer's choice: TTH ───────── Pick a sequence of 3 coin tosses of H or T (Heads or Tails) or Quit: tht ◄■■■■■■■■■■■ human's input ───────── your pick: THT ───────── computer's pick: TTH ───────── The computer won this toss with 3 coin tosses. ───────── The tossed coin series was: TTH ───────── You've won 2 games out of 6. ╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩╦╩ ───────── You win the first toss, so you pick your sequence first. ───────── Pick a sequence of 3 coin tosses of H or T (Heads or Tails) or Quit: quit ◄■■■■■■■■■■■ human's input
Ruby
Toss = [:Heads, :Tails]
def yourChoice
puts "Enter your choice (H/T)"
choice = []
3.times do
until (c = $stdin.getc.upcase) == "H" or c == "T"
end
choice << (c=="H" ? Toss[0] : Toss[1])
end
puts "You chose #{choice.join(' ')}"
choice
end
loop do
puts "\n%s I start, %s you start ..... %s" % [*Toss, coin = Toss.sample]
if coin == Toss[0]
myC = Toss.shuffle << Toss.sample
puts "I chose #{myC.join(' ')}"
yC = yourChoice
else
yC = yourChoice
myC = Toss - [yC[1]] + yC.first(2)
puts "I chose #{myC.join(' ')}"
end
seq = Array.new(3){Toss.sample}
print seq.join(' ')
loop do
puts "\n I win!" or break if seq == myC
puts "\n You win!" or break if seq == yC
seq.push(Toss.sample).shift
print " #{seq[-1]}"
end
end
- Output:
Heads I start, Tails you start ..... Tails Enter your choice (H/T) THT You chose Tails Heads Tails I chose Tails Tails Heads Heads Tails Heads Heads Tails Tails Tails Heads I win! Heads I start, Tails you start ..... Heads I chose Heads Heads Heads Enter your choice (H/T) THH You chose Tails Heads Heads Heads Heads Tails Heads Tails Heads Tails Tails Tails Tails Tails Tails Tails Heads Heads You win!
Rust
extern crate rand;
use std::io::{stdin, stdout, Write};
use std::thread;
use std::time::Duration;
use rand::Rng;
fn toss_coin<R: Rng>(rng: &mut R, print: bool) -> char {
let c = if rng.gen() { 'H' } else { 'T' };
if print {
print!("{}", c);
stdout().flush().expect("Could not flush stdout");
}
c
}
fn gen_sequence<R: Rng>(rng: &mut R, seed: Option<&str>) -> String {
let mut seq = String::new();
match seed {
Some(s) => {
let mut iter = s.chars();
let c0 = iter.next().unwrap();
let next = if c0 == 'H' { 'T' } else { 'H' };
seq.push(next);
seq.push(c0);
seq.push(iter.next().unwrap());
}
None => {
for _ in 0..3 {
seq.push(toss_coin(rng, false))
}
}
}
seq
}
fn read_sequence(used_seq: Option<&str>) -> String {
let mut seq = String::new();
loop {
seq.clear();
println!("Please, enter sequence of 3 coins: H (heads) or T (tails): ");
stdin().read_line(&mut seq).expect("failed to read line");
seq = seq.trim().to_uppercase();
// do the cheapest test first
if seq.len() == 3
&& seq.chars().all(|c| c == 'H' || c == 'T')
&& seq != used_seq.unwrap_or("")
{
return seq;
}
println!("Please enter correct sequence!");
}
}
fn main() {
let mut rng = rand::thread_rng();
println!("--Penney's game--");
loop {
let useq: String;
let aiseq: String;
if rng.gen::<bool>() {
println!("You choose first!");
useq = read_sequence(None);
println!("Your sequence: {}", useq);
aiseq = gen_sequence(&mut rng, Some(&useq));
println!("My sequence: {}", aiseq);
} else {
println!("I choose first!");
aiseq = gen_sequence(&mut rng, None);
println!("My sequence: {}", aiseq);
useq = read_sequence(Some(&aiseq));
println!("Your sequence: {}", useq);
}
println!("Tossing coins...");
let mut coins = String::new();
for _ in 0..2 {
// toss first 2 coins
coins.push(toss_coin(&mut rng, true));
thread::sleep(Duration::from_millis(500));
}
loop {
coins.push(toss_coin(&mut rng, true));
thread::sleep(Duration::from_millis(500));
if coins.contains(&useq) {
println!("\nYou win!");
break;
}
if coins.contains(&aiseq) {
println!("\nI win!");
break;
}
}
println!(" Play again? 'Y' to play, 'Q' to exit.");
let mut input = String::new();
stdin().read_line(&mut input).expect("failed to read line");
match input.trim_start().chars().next().unwrap() {
'Y' | 'y' => continue,
_ => break,
}
}
}
- Output:
--Penney's game-- You choose first! Please, enter sequence of 3 coins: H (heads) or T (tails): hht Your sequence: HHT My sequence: THH Tossing coins... TTTTHTTHTHTHTTTHH I win! Play again? 'Y' to play, 'Q' to exit.
Tcl
package require Tcl 8.6
oo::class create Player {
variable who seq seen idx
constructor {name sequence} {
set who $name
set seq $sequence
set seen {}
set idx end-[expr {[string length $seq] - 1}]
}
method pick {} {
return $seq
}
method name {} {
return $who
}
method match {digit} {
append seen $digit
return [expr {[string range $seen $idx end] eq $seq}]
}
}
oo::class create HumanPlayer {
superclass Player
constructor {length {otherPlayersSelection ""}} {
fconfigure stdout -buffering none
while true {
puts -nonewline "What do you pick? (length $length): "
if {[gets stdin pick] < 0} exit
set pick [regsub -all {[^HT]} [string map {0 H 1 T h H t T} $pick] ""]
if {[string length $pick] eq $length} break
puts "That's not a legal pick!"
}
set name "Human"
if {[incr ::humans] > 1} {append name " #$::humans"}
next $name $pick
}
}
oo::class create RobotPlayer {
superclass Player
constructor {length {otherPlayersSelection ""}} {
if {$otherPlayersSelection eq ""} {
set pick ""
for {set i 0} {$i < $length} {incr i} {
append pick [lindex {H T} [expr {int(rand()*2)}]]
}
} else {
if {$length != 3} {
error "lengths other than 3 not implemented"
}
lassign [split $otherPlayersSelection ""] a b c
set pick [string cat [string map {H T T H} $b] $a $b]
}
set name "Robot"
if {[incr ::robots] > 1} {append name " #$::robots"}
puts "$name picks $pick"
next $name $pick
}
}
proc game {length args} {
puts "Let's play Penney's Game!"
# instantiate the players
set picks {}
set players {}
while {[llength $args]} {
set idx [expr {int(rand()*[llength $args])}]
set p [[lindex $args $idx] new $length {*}$picks]
set args [lreplace $args $idx $idx]
lappend players $p
lappend picks [$p pick]
}
# sanity check
if {[llength $picks] != [llength [lsort -unique $picks]]} {
puts "Two players picked the same thing; that's illegal"
}
# do the game loop
while 1 {
set coin [lindex {H T} [expr {int(rand()*2)}]]
puts "Coin flip [incr counter] is $coin"
foreach p $players {
if {[$p match $coin]} {
puts "[$p name] has won!"
return
}
}
}
}
game 3 HumanPlayer RobotPlayer
- Sample Game:
Let's play Penney's Game! What do you pick? (length 3): HTH Robot picks HHT Coin flip 1 is T Coin flip 2 is H Coin flip 3 is T Coin flip 4 is T Coin flip 5 is T Coin flip 6 is H Coin flip 7 is T Coin flip 8 is T Coin flip 9 is H Coin flip 10 is T Coin flip 11 is T Coin flip 12 is T Coin flip 13 is H Coin flip 14 is T Coin flip 15 is T Coin flip 16 is H Coin flip 17 is T Coin flip 18 is T Coin flip 19 is H Coin flip 20 is T Coin flip 21 is H Human has won!
UNIX Shell
#!/bin/bash
main() {
printf $'Penney\'s Game\n\n'
printf 'Flipping to see who goes first ... '
if [[ $(flip) == H ]]; then
printf 'I do.\n'
p2=$(choose_sequence)
printf 'I choose: %s\n' "$p2"
else
printf 'You do.\n'
fi
while true; do
read -p 'Enter your three-flip sequence: ' p1
p1=$(tr a-z A-Z <<<"$p1")
case "$p1" in
"$p2") printf 'Sequence must be different from mine\n';;
[HT][HT][HT]) break;;
*) printf $'Sequence must be three H\'s or T\'s\n';;
esac
done
if [ -z "$p2" ]; then
p2=$(choose_sequence "$p1")
printf 'I choose: %s\n' "$p2"
fi
printf '\nHere we go. %s, you win; %s, I win.\n' "$p1" "$p2"
printf 'Flips:'
flips=
while true; do
flip=$(flip)
printf ' %s' "$flip"
flips+=$flip
case "$flips" in
*$p1) printf $'\nYou win!\n'; exit 0;;
*$p2) printf $'\nI win!\n'; exit 1;;
esac
done
}
choose_sequence() {
local result
if (( $# )); then
case "$1" in
?[Hh]?) result=T;;
*) result=H;;
esac
result+="${1%?}"
else
result=$(flip)$(flip)$(flip)
fi
printf '%s\n' "$result"
}
flip() {
if (( RANDOM % 2 )); then
printf '%s\n' H
else
printf '%s\n' T
fi
}
main "$@"
- Output:
PC first:
Penney's Game Flipping to see who goes first ... I do. I choose: HHT Enter your three-flip sequence: THH Here we go. THH, you win; HHT, I win. THH You win!
Human first:
Penney's Game Flipping to see who goes first ... I do. I choose: HHH Enter your three-flip sequence: THH Here we go. THH, you win; HHH, I win. Flips: H H T H H You win!
Human first:
Penney's Game Flipping to see who goes first ... You do. Enter your three-flip sequence: THH I choose: TTH Here we go. THH, you win; TTH, I win. Flips: H H T T T H I win!
VBA
Option Explicit
Private Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)
Private Const HT As String = "H T"
Public Sub PenneysGame()
Dim S$, YourSeq$, ComputeSeq$, i&, Seq$, WhoWin$, flag As Boolean
Do
S = WhoWillBeFirst(Choice("Who will be first"))
If S = "ABORT" Then Exit Do
Debug.Print S; " start"
YourSeq = Choice("Your sequence", 3)
If YourSeq Like "*ABORT*" Then Exit Do
Debug.Print "Your sequence : " & YourSeq
ComputeSeq = vbNullString
For i = 1 To 3
ComputeSeq = ComputeSeq & Random
Next i
Debug.Print "Computer sequence : " & ComputeSeq
Seq = vbNullString
Do
Seq = Seq & Random
Debug.Print Seq
Sleep 1000
Loop While Not Winner(ComputeSeq, YourSeq, Seq, WhoWin)
Debug.Print WhoWin; " win"
If MsgBox(WhoWin & " win" & vbCrLf & "Play again?", vbYesNo) = vbNo Then flag = True
Debug.Print ""
Loop While Not flag
Debug.Print "Game over"
End Sub
Private Function WhoWillBeFirst(YourChoice As String) As String
Dim S$
S = Random
Select Case YourChoice
Case "ABORT": WhoWillBeFirst = YourChoice
Case Else:
WhoWillBeFirst = IIf(S = YourChoice, "You", "Computer")
End Select
End Function
Private Function Choice(Title As String, Optional Seq As Integer) As String
Dim S$, i&, t$
If Seq = 0 Then Seq = 1
t = Title
For i = 1 To Seq
S = vbNullString
Do
S = InputBox("Choose between H or T : ", t)
If StrPtr(S) = 0 Then S = "Abort"
S = UCase(S)
Loop While S <> "H" And S <> "T" And S <> "ABORT"
Choice = Choice & S
t = Title & " " & Choice
If Choice Like "*ABORT*" Then Exit For
Next i
End Function
Private Function Random() As String
Randomize Timer
Random = Split(HT, " ")(CInt(Rnd))
End Function
Private Function Winner(Cs$, Ys$, S$, W$) As Boolean
If Len(S) < 3 Then
Winner = False
Else
If Right(S, 3) = Cs And Right(S, 3) = Ys Then
Winner = True
W = "Computer & you"
ElseIf Right(S, 3) = Cs And Right(S, 3) <> Ys Then
Winner = True
W = "Computer"
ElseIf Right(S, 3) = Ys And Right(S, 3) <> Cs Then
Winner = True
W = "You"
End If
End If
End Function
- Output:
You start Your sequence : HHT Computer sequence : TTH H HT HTT HTTH Computer win You start Your sequence : TTH Computer sequence : HHH T TT TTT TTTH You win Game over
V (Vlang)
import rand
import os
import time
const optimum = {
"HHH": "THH", "HHT": "THH", "HTH": "HHT", "HTT": "HHT",
"THH": "TTH", "THT": "TTH", "TTH": "HTT", "TTT": "HTT"
}
fn main() {
r := rand.intn(2) or {exit(1)}
mut user_seq :=''
mut comp_seq :=''
mut coin :=''
mut coins :=''
mut len := 0
mut seq :=''
if r == 0 {
println("You go first")
user_seq = user_sequence()
println('\n')
comp_seq = computer_sequence(user_seq)
}
else {
println("Computer goes first")
comp_seq = computer_sequence(user_seq)
println('\n')
user_seq = user_sequence()
}
println('\n')
for true {
if (rand.intn(2) or {exit(1)}) == 0 {coin = 'H'} else {coin = 'T'}
coins += coin
println("Coins flipped: $coins")
len = coins.len
if len >= 3 {
seq = coins.substr(len - 3, len)
if seq == user_seq {
println("\nYou win!")
exit(0)
}
if seq == comp_seq {
println("\nComputer wins!")
exit(0)
}
}
time.sleep(1 * time.second) // extraneous
}
}
fn user_sequence() string {
mut user_seq :=''
println("A sequence of three H or T should be entered")
for (user_seq.len != 3) || (user_seq.to_upper().split('').any(it != 'H' && it != 'T') == true) {
user_seq = os.input('Enter your sequence: ').str().to_upper()
}
return user_seq
}
fn computer_sequence(user_seq string) string {
mut char_array := []string{len:3}
mut comp_seq :=''
if user_seq == '' {
for _ in 0..2 {
if (rand.intn(2) or {exit(1)}) == 0 {char_array << 'T'} else {char_array << 'H'}
comp_seq = char_array.join('')
}
}
else {
comp_seq = optimum[user_seq]
}
println("Computer's sequence: $comp_seq")
return comp_seq
}- Output:
Computer goes first Computer's sequence: TH A sequence of three H or T should be entered Enter your sequence: thh Coins flipped: H Coins flipped: HT Coins flipped: HTT Coins flipped: HTTH Coins flipped: HTTHT Coins flipped: HTTHTH Coins flipped: HTTHTHT Coins flipped: HTTHTHTT Coins flipped: HTTHTHTTH Coins flipped: HTTHTHTTHT Coins flipped: HTTHTHTTHTH Coins flipped: HTTHTHTTHTHT Coins flipped: HTTHTHTTHTHTH Coins flipped: HTTHTHTTHTHTHT Coins flipped: HTTHTHTTHTHTHTH Coins flipped: HTTHTHTTHTHTHTHH You win!
Wren
import "random" for Random
import "io" for Stdin, Stdout
import "timer" for Timer
import "./str" for Str
var rand = Random.new()
var optimum = {
"HHH": "THH", "HHT": "THH", "HTH": "HHT", "HTT": "HHT",
"THH": "TTH", "THT": "TTH", "TTH": "HTT", "TTT": "HTT"
}
var getUserSequence = Fn.new {
System.print("A sequence of three H or T should be entered")
var userSeq
while (true) {
System.write("Enter your sequence: ")
Stdout.flush()
userSeq = Str.upper(Stdin.readLine())
if (userSeq.count == 3 && userSeq.all { |c| c == "H" || c == "T" }) break
}
return userSeq
}
var getComputerSequence = Fn.new { |userSeq|
var compSeq
if (userSeq == "") {
var chars = List.filled(3, null)
for (i in 0..2) chars[i] = (rand.int(2) == 0) ? "T" : "H"
compSeq = chars.join()
} else {
compSeq = optimum[userSeq]
}
System.print("Computer's sequence: %(compSeq)")
return compSeq
}
var userSeq
var compSeq
var r = rand.int(2)
if (r == 0) {
System.print("You go first")
userSeq = getUserSequence.call()
System.print()
compSeq = getComputerSequence.call(userSeq)
} else {
System.print("Computer goes first")
compSeq = getComputerSequence.call("")
System.print()
userSeq = getUserSequence.call()
}
System.print()
var coins = ""
while (true) {
var coin = (rand.int(2) == 0) ? "H" : "T"
coins = coins + coin
System.print("Coins flipped: %(coins)")
var len = coins.count
if (len >= 3) {
var seq = coins[len-3...len]
if (seq == userSeq) {
System.print("\nYou win!")
return
} else if (seq == compSeq) {
System.print("\nCompter wins!")
return
}
}
Timer.sleep(2000) // wait two seconds for next flip
}
- Output:
Sample game where computer goes first:
Computer goes first Computer's sequence: HHH A sequence of three H or T should be entered Enter your sequence: TTH Coins flipped: H Coins flipped: HH Coins flipped: HHH Compter wins!
Sample game where user goes first:
You go first A sequence of three H or T should be entered Enter your sequence: TTH Computer's sequence: HTT Coins flipped: H Coins flipped: HH Coins flipped: HHH Coins flipped: HHHT Coins flipped: HHHTT Compter wins!
zkl
fcn coinToss{ (0).random(2) and "H" or "T" } // (0).random(2) --> 0<=r<2
reg myBet, yourBet;
if(coinToss()=="H"){ // The toss says I go first
myBet=(3).pump(String,coinToss);
println("I bet ",myBet);
yourBet=ask("Your bet of three (H/T): ")[0,3].toUpper();
}else{
yourBet=ask("Your bet of three (H/T): ")[0,3].toUpper();
myBet=((yourBet[1]=="H") and "T" or "H") + yourBet[0,2];
println("I bet ",myBet);
}
print("Flipping: "); coins:="";
while(1){
print(toss:=coinToss()); coins=coins + toss;
if(Void!=coins.find(yourBet)){ println(" You win!"); break; }
if(Void!=coins.find(myBet)) { println(" I win!"); break; }
// ignore we both won
}- Output:
$ zkl bbb Your bet of three (H/T): tth I bet HTT Flipping: HHHHHHTHHTHHHTHTHHHTHTHTT I win! $ zkl bbb I bet THT Your bet of three (H/T): hhh Flipping: THHH You win!
Categories:
- Programming Tasks
- Games
- 11l
- Ada
- AutoHotkey
- Amazing Hopper
- BASIC
- Applesoft BASIC
- BASIC256
- Sinclair ZX81 BASIC
- Batch File
- BBC BASIC
- C
- C sharp
- C++
- Clojure
- Common Lisp
- D
- Elixir
- Factor
- FreeBASIC
- Go
- Haskell
- J
- Java
- Julia
- Kotlin
- Lua
- MiniScript
- Nim
- Pascal
- Perl
- Phix
- PicoLisp
- Prolog
- Python
- Quackery
- R
- Racket
- Raku
- REXX
- Ruby
- Rust
- Tcl
- UNIX Shell
- VBA
- V (Vlang)
- Wren
- Wren-str
- Zkl