Rock-paper-scissors
You are encouraged to solve this task according to the task description, using any language you may know.
- Task
Implement the classic children's game Rock-paper-scissors, as well as a simple predictive AI (artificial intelligence) player.
Rock Paper Scissors is a two player game.
Each player chooses one of rock, paper or scissors, without knowing the other player's choice.
The winner is decided by a set of rules:
- Rock beats scissors
- Scissors beat paper
- Paper beats rock
If both players choose the same thing, there is no winner for that round.
For this task, the computer will be one of the players.
The operator will select Rock, Paper or Scissors and the computer will keep a record of the choice frequency, and use that information to make a weighted random choice in an attempt to defeat its opponent.
- Extra credit
Support additional choices additional weapons.
Ada
<lang Ada>with Ada.Text_IO; with Ada.Numerics.Float_Random;
procedure Rock_Paper_Scissors is
package Rand renames Ada.Numerics.Float_Random; Gen: Rand.Generator;
type Choice is (Rock, Paper, Scissors);
Cnt: array (Choice) of Natural := (1, 1, 1);
-- for the initialization: pretend that each of Rock, Paper,
-- and Scissors, has been played once by the human
-- else the first computer choice would be deterministic
function Computer_Choice return Choice is
Random_Number: Natural :=
Integer(Rand.Random(Gen)
* (Float(Cnt(Rock)) + Float(Cnt(Paper)) + Float(Cnt(Scissors))));
begin
if Random_Number < Cnt(Rock) then
-- guess the human will choose Rock
return Paper;
elsif Random_Number - Cnt(Rock) < Cnt(Paper) then
-- guess the human will choose Paper
return Scissors;
else -- guess the human will choose Scissors
return Rock;
end if;
end Computer_Choice;
Finish_The_Game: exception;
function Human_Choice return Choice is
Done: Boolean := False;
T: constant String
:= "enter ""r"" for Rock, ""p"" for Paper, or ""s"" for Scissors""!";
U: constant String
:= "or enter ""q"" to Quit the game";
Result: Choice;
begin
Ada.Text_IO.Put_Line(T);
Ada.Text_IO.Put_Line(U);
while not Done loop
Done := True;
declare
S: String := Ada.Text_IO.Get_Line;
begin
if S="r" or S="R" then
Result := Rock;
elsif S="p" or S = "P" then
Result := Paper;
elsif S="s" or S="S" then
Result := Scissors;
elsif S="q" or S="Q" then
raise Finish_The_Game;
else
Done := False;
end if;
end;
end loop;
return Result;
end Human_Choice;
type Result is (Human_Wins, Draw, Computer_Wins);
function "<" (X, Y: Choice) return Boolean is
-- X < Y if X looses against Y
begin
case X is
when Rock => return (Y = Paper);
when Paper => return (Y = Scissors);
when Scissors => return (Y = Rock);
end case;
end "<";
Score: array(Result) of Natural := (0, 0, 0);
C,H: Choice;
Res: Result;
begin
-- play the game
loop
C := Computer_Choice; -- the computer makes its choice first
H := Human_Choice; -- now ask the player for his/her choice
Cnt(H) := Cnt(H) + 1; -- update the counts for the AI
if C < H then
Res := Human_Wins;
elsif H < C then
Res := Computer_Wins;
else
Res := Draw;
end if;
Ada.Text_IO.Put_Line("COMPUTER'S CHOICE: " & Choice'Image(C)
& " RESULT: " & Result'Image(Res));
Ada.Text_IO.New_Line;
Score(Res) := Score(Res) + 1;
end loop;
exception
when Finish_The_Game =>
Ada.Text_IO.New_Line;
for R in Score'Range loop
Ada.Text_IO.Put_Line(Result'Image(R) & Natural'Image(Score(R)));
end loop;
end Rock_Paper_Scissors;</lang>
First and last few lines of the output of a game, where the human did permanently choose Rock:
./rock_paper_scissors enter "r" for Rock, "p" for Paper, or "s" for Scissors"! or enter "q" to Quit the game r COMPUTER'S CHOICE: SCISSORS RESULT: HUMAN_WINS enter "r" for Rock, "p" for Paper, or "s" for Scissors"! or enter "q" to Quit the game r COMPUTER'S CHOICE: ROCK RESULT: DRAW enter "r" for Rock, "p" for Paper, or "s" for Scissors"! or enter "q" to Quit the game r COMPUTER'S CHOICE: SCISSORS RESULT: HUMAN_WINS enter "r" for Rock, "p" for Paper, or "s" for Scissors"! or enter "q" to Quit the game r COMPUTER'S CHOICE: ROCK RESULT: DRAW [...] enter "r" for Rock, "p" for Paper, or "s" for Scissors"! or enter "q" to Quit the game r COMPUTER'S CHOICE: ROCK RESULT: DRAW enter "r" for Rock, "p" for Paper, or "s" for Scissors"! or enter "q" to Quit the game r COMPUTER'S CHOICE: PAPER RESULT: COMPUTER_WINS enter "r" for Rock, "p" for Paper, or "s" for Scissors"! or enter "q" to Quit the game q HUMAN_WINS 2 DRAW 5 COMPUTER_WINS 21
Aime
<lang aime>text computer_play(record plays, record beats) {
integer a, c, total; text s;
total = plays["rock"] + plays["paper"] + plays["scissors"];
a = drand(total - 1);
for (s, c in plays) {
if (a < c) {
break;
}
a -= c;
}
beats[s];
}
integer main(void) {
integer computer, human; record beats, plays; file f; text s;
computer = human = 0;
f.stdin;
beats["rock"] = "paper"; beats["paper"] = "scissors"; beats["scissors"] = "rock";
plays["rock"] = 1; plays["paper"] = 1; plays["scissors"] = 1;
while (1) {
o_text("Your choice [rock/paper/scissors]:\n");
if (f.line(s) == -1) {
break;
}
if (!plays.key(s)) {
o_text("Invalid choice, try again\n");
} else {
text c;
c = computer_play(plays, beats);
o_form("Human: ~, Computer: ~\n", s, c);
if (s == c) {
o_text("Draw\n");
} elif (c == beats[s]) {
computer += 1;
o_text("Computer wins\n");
} else {
human += 1;
o_text("Human wins\n");
}
plays.up(s);
o_form("Score: Human: ~, Computer: ~\n", human, computer);
}
}
return 0;
}</lang>
ALGOL 68
<lang algol68>BEGIN
# rock/paper/scissors game #
# counts of the number of times the player has chosen each move #
# we initialise each to 1 so that the total isn't zero when we are #
# choosing the computer's first move (as in the Ada version) #
INT r count := 1;
INT p count := 1;
INT s count := 1;
# counts of how many games the player and computer have won #
INT player count := 0;
INT computer count := 0;
print( ( "rock/paper/scissors", newline, newline ) );
WHILE
CHAR player move;
# get the players move - r => rock, p => paper, s => scissors #
# q => quit #
WHILE
print( ( "Please enter your move (r/p/s) or q to quit: " ) );
read( ( player move, newline ) );
( player move /= "r"
AND player move /= "p"
AND player move /= "s"
AND player move /= "q"
)
DO
print( ( "Unrecognised move", newline ) )
OD;
# continue playing until the player chooses quit #
player move /= "q"
DO
# decide the computer's move based on the player's history #
CHAR computer move;
INT move count = r count + p count + s count;
# predict player will play rock if the random number #
# is in the range 0 .. rock / total #
# predict player will play paper if the random number #
# is in the range rock / total .. ( rock + paper ) / total #
# predict player will play scissors otherwise #
REAL r limit = r count / move count;
REAL p limit = r limit + ( p count / move count );
REAL random move = next random;
IF random move < r limit THEN
# we predict the player will choose rock - we choose paper #
computer move := "p"
ELIF random move < p limit THEN
# we predict the player will choose paper - we choose scissors #
computer move := "s"
ELSE
# we predict the player will choose scissors - we choose rock #
computer move := "r"
FI;
print( ( "You chose: " + player move, newline ) );
print( ( "I chose: " + computer move, newline ) );
IF player move = computer move THEN
# both players chose the same - draw #
print( ( "We draw", newline ) )
ELSE
# players chose different moves - there is a winner #
IF ( player move = "r" AND computer move = "s" )
OR ( player move = "p" AND computer move = "r" )
OR ( player move = "s" AND computer move = "p" )
THEN
player count +:= 1;
print( ( "You win", newline ) )
ELSE
computer count +:= 1;
print( ( "I win", newline ) )
FI;
print( ( "You won: "
, whole( player count , 0 )
, ", I won: "
, whole( computer count, 0 )
, newline
)
)
FI;
IF player move = "r" THEN
# player chose rock #
r count +:= 1
ELIF player move = "p" THEN
# player chose paper #
p count +:= 1
ELSE
# player chose scissors #
s count +:= 1
FI
OD;
print( ( "Thanks for a most enjoyable game", newline ) )
END</lang>
AutoHotkey
<lang AHK>DllCall("AllocConsole") Write("Welcome to Rock-Paper-Scissors`nMake a choice: ")
cR := cP := cS := 0 ; user choice count userChoice := Read() Write("My choice: " . cpuChoice := MakeChoice(1, 1, 1))
Loop { Write(DecideWinner(userChoice, cpuChoice) . "`nMake A Choice: ") cR += SubStr(userChoice, 1, 1) = "r", cP += InStr(userChoice, "P"), cS += InStr(userChoice, "S") userChoice := Read() Write("My Choice: " . cpuChoice := MakeChoice(cR, cP, cS)) }
MakeChoice(cR, cP, cS){ ; parameters are number of times user has chosen each item total := cR + cP + cS
Random, rand, 0.0, 1.0 if (rand >= 0 and rand <= cR / total) return "Paper" else if (rand > cR / total and rand <= (cR + cP) / total) return "Scissors" else return "Rock" }
DecideWinner(user, cpu){ user := SubStr(user, 1, 1), cpu := SubStr(cpu, 1, 1) if (user = cpu) return "`nTie!" else if (user = "r" and cpu = "s") or (user = "p" and cpu = "r") or (user = "s" and cpu = "p") return "`nYou Win!" else return "`nI Win!" }
Read(){ FileReadLine, a, CONIN$, 1 return a } Write(txt){ FileAppend, % txt, CONOUT$ }</lang>
AutoIt
I´ve created a GUI to play and show results, no Console Input
<lang autoit> RPS()
Func RPS() Local $ai_Played_games[4] $ai_Played_games[0] = 3 For $I = 1 To 3 $ai_Played_games[$I] = 1 Next $RPS = GUICreate("Rock Paper Scissors", 338, 108, 292, 248) $Rock = GUICtrlCreateButton("Rock", 8, 8, 113, 25, 131072) $Paper = GUICtrlCreateButton("Paper", 8, 40, 113, 25, 131072) $Scissors = GUICtrlCreateButton("Scissors", 8, 72, 113, 25, 131072) $Label1 = GUICtrlCreateLabel("W:", 136, 8, 18, 17) $Wins = GUICtrlCreateLabel("0", 160, 8, 36, 17) $Label3 = GUICtrlCreateLabel("L:", 208, 8, 13, 17) $Looses = GUICtrlCreateLabel("0", 224, 8, 36, 17) $Label5 = GUICtrlCreateLabel("D:", 272, 8, 15, 17) $Deuce = GUICtrlCreateLabel("0", 296, 8, 36, 17) $Displaybutton = GUICtrlCreateButton("", 136, 48, 193, 49, 131072) GUICtrlSetState($ai_Played_games, 128) GUISetState(@SW_SHOW) While 1 $nMsg = GUIGetMsg() Switch $nMsg Case -3 Exit Case $Rock $Ret = _RPS_Eval(1, $ai_Played_games) GUICtrlSetData($Displaybutton, $Ret) If $Ret = "Deuce" Then GUICtrlSetData($Deuce, Guictrlread($Deuce)+1) Elseif $Ret = "You Loose" Then GUICtrlSetData($Looses, Guictrlread($Looses)+1) Elseif $Ret = "You Win" Then GUICtrlSetData($Wins, Guictrlread($Wins)+1) EndIf Case $Paper $Ret = _RPS_Eval(2, $ai_Played_games) GUICtrlSetData($Displaybutton, $Ret) If $Ret = "Deuce" Then GUICtrlSetData($Deuce, Guictrlread($Deuce)+1) Elseif $Ret = "You Loose" Then GUICtrlSetData($Looses, Guictrlread($Looses)+1) Elseif $Ret = "You Win" Then GUICtrlSetData($Wins, Guictrlread($Wins)+1) EndIf Case $Scissors $Ret = _RPS_Eval(3, $ai_Played_games) GUICtrlSetData($Displaybutton, $Ret) If $Ret = "Deuce" Then GUICtrlSetData($Deuce, Guictrlread($Deuce)+1) Elseif $Ret = "You Loose" Then GUICtrlSetData($Looses, Guictrlread($Looses)+1) Elseif $Ret = "You Win" Then GUICtrlSetData($Wins, Guictrlread($Wins)+1) EndIf EndSwitch WEnd
EndFunc ;==>RPS
Func _RPS_Eval($i_Player_Choose, $ai_Played_games) Local $i_choice = 1 $i_rnd = Random(1, 1000, 1) $i_choose_1 = ($ai_Played_games[1] / $ai_Played_games[0] * 1000) $i_choose_2 = ($ai_Played_games[2] / $ai_Played_games[0] * 1000) $i_choose_3 = ($ai_Played_games[3] / $ai_Played_games[0] * 1000) If $i_rnd < $i_choose_1 Then $i_choice = 2 ElseIf $i_rnd < $i_choose_1 + $i_choose_2 And $i_rnd > $i_choose_1 Then $i_choice = 3 ElseIf $i_rnd < $i_choose_1 + $i_choose_2 + $i_choose_3 And $i_rnd > $i_choose_1 + $i_choose_2 Then $i_choice = 1 EndIf $ai_Played_games[0] += 1 If $i_Player_Choose = 1 Then $ai_Played_games[1] += 1 If $i_choice = 1 Then Return "Deuce" If $i_choice = 2 Then Return "You Loose" If $i_choice = 3 Then Return "You Win" ElseIf $i_Player_Choose = 2 Then $ai_Played_games[2] += 1 If $i_choice = 2 Then Return "Deuce" If $i_choice = 3 Then Return "You Loose" If $i_choice = 1 Then Return "You Win" ElseIf $i_Player_Choose = 3 Then $ai_Played_games[3] += 1 If $i_choice = 3 Then Return "Deuce" If $i_choice = 1 Then Return "You Loose" If $i_choice = 2 Then Return "You Win" EndIf EndFunc ;==>_RPS_Eval
</lang>
BASIC
<lang qbasic>DIM pPLchoice(1 TO 3) AS INTEGER, pCMchoice(1 TO 3) AS INTEGER DIM choices(1 TO 3) AS STRING DIM playerwins(1 TO 3) AS INTEGER DIM playerchoice AS INTEGER, compchoice AS INTEGER DIM playerwon AS INTEGER, compwon AS INTEGER, tie AS INTEGER DIM tmp AS INTEGER
' Do it this way for QBasic; FreeBASIC supports direct array assignment. DATA "rock", "paper", "scissors" FOR tmp = 1 to 3
READ choices(tmp)
NEXT DATA 3, 1, 2 FOR tmp = 1 to 3
READ playerwins(tmp)
NEXT
RANDOMIZE TIMER
DO
' Computer chooses first to ensure there's no "cheating".
compchoice = INT(RND * (pPLchoice(1) + pPLchoice(2) + pPLchoice(3) + 3))
SELECT CASE compchoice
CASE 0 to (pPLchoice(1))
' Player past choice: rock; choose paper.
compchoice = 2
CASE (pPLchoice(1) + 1) TO (pPLchoice(1) + pPLchoice(2) + 1)
' Player past choice: paper; choose scissors.
compchoice = 3
CASE (pPLchoice(1) + pPLchoice(2) + 2) TO (pPLchoice(1) + pPLchoice(2) + pPLchoice(3) + 2)
' Player past choice: scissors; choose rock.
compchoice = 1
END SELECT
PRINT "Rock, paper, or scissors ";
DO
PRINT "[1 = rock, 2 = paper, 3 = scissors, 0 to quit]";
INPUT playerchoice
LOOP WHILE (playerchoice < 0) OR (playerchoice > 3)
IF 0 = playerchoice THEN EXIT DO
pCMchoice(compchoice) = pCMchoice(compchoice) + 1
pPLchoice(playerchoice) = pPLchoice(playerchoice) + 1
PRINT "You chose "; choices(playerchoice); " and I chose "; choices(compchoice); ". ";
IF (playerchoice) = compchoice THEN
PRINT "Tie!"
tie = tie + 1
ELSEIF (compchoice) = playerwins(playerchoice) THEN
PRINT "You won!"
playerwon = playerwon + 1
ELSE
PRINT "I won!"
compwon = compwon + 1
END IF
LOOP
PRINT "Some useless statistics:" PRINT "You won "; STR$(playerwon); " times, and I won "; STR$(compwon); " times; "; STR$(tie); " ties." PRINT , choices(1), choices(2), choices(3) PRINT "You chose:", pPLchoice(1), pPLchoice(2), pPLchoice(3) PRINT " I chose:", pCMchoice(1), pCMchoice(2), pCMchoice(3)</lang>
A sample game:
$ ./rokpprscr
Rock, paper, or scissors [1 = rock, 2 = paper, 3 = scissors, 0 to quit]? 1
You chose rock and I chose paper. I won!
Rock, paper, or scissors [1 = rock, 2 = paper, 3 = scissors, 0 to quit]? 1
You chose rock and I chose scissors. You won!
[... 56 more times choosing "rock"...]
Rock, paper, or scissors [1 = rock, 2 = paper, 3 = scissors, 0 to quit]? 1
You chose rock and I chose paper. I won!
Rock, paper, or scissors [1 = rock, 2 = paper, 3 = scissors, 0 to quit]? 1
You chose rock and I chose paper. I won!
Rock, paper, or scissors [1 = rock, 2 = paper, 3 = scissors, 0 to quit]? 3
You chose scissors and I chose paper. You won!
Rock, paper, or scissors [1 = rock, 2 = paper, 3 = scissors, 0 to quit]?
Some useless statistics:
You won 5 times, and I won 54 times; 2 ties.
rock paper scissors
You chose: 60 0 1
I chose: 2 55 4
Bash
<lang bash>#!/bin/bash echo "What will you choose? [rock/paper/scissors]" read response aiThought=$(echo $[ 1 + $[ RANDOM % 3 ]]) case $aiThought in 1) aiResponse="rock" ;; 2) aiResponse="paper" ;; 3) aiResponse="scissors" ;; esac echo "AI - $aiResponse" responses="$response$aiResponse" case $responses in rockrock) isTie=1 ;; rockpaper) playerWon=0 ;; rockscissors) playerWon=1 ;; paperrock) playerWon=1 ;; paperpaper) isTie=1 ;; paperscissors) playerWon=0 ;; scissorsrock) playerWon=0 ;; scissorspaper) playerWon=1 ;; scissorsscissors) isTie=1 ;; esac if $isTie == 1 ; then echo "It's a tie!" && exit 1 ; fi if $playerWon == 0 ; then echo "Sorry, $aiResponse beats $response , try again.." && exit 1 ; fi if $playerWon == 1 ; then echo "Good job, $response beats $aiResponse!" && exit 1 ; fi</lang>
Batch File
<lang dos> @echo off setlocal enabledelayedexpansion
set choice1=rock set choice2=paper set choice3=scissors set freq1=0 set freq2=0 set freq3=0 set games=0 set won=0 set lost=0 set tie=0
- start
cls echo Games - %games% : Won - %won% : Lost - %lost% : Ties - %tie% choice /c RPS /n /m "[R]ock, [P]aper or [S]cissors? "
set /a choicequant+=1 set choice=%errorlevel% set /a rocklimit=100 / %choicequant% * %freq3% set /a scissorslimit=100 - (100 / %choicequant% * %freq2%) set /a randchoice=%random% %% 100 + 1 set compchoice=2 if %randchoice% geq %scissorslimit% set compchoice=3 if %randchoice% leq %rocklimit% set compchoice=1
cls echo Player: !choice%choice%! ^|vs^| Computer: !choice%compchoice%! goto %compchoice%
- 1
if %choice%==1 goto tie if %choice%==2 goto win if %choice%==3 goto loss
- 2
if %choice%==1 goto loss if %choice%==2 goto tie if %choice%==3 goto win
- 3
if %choice%==1 goto win if %choice%==2 goto loss if %choice%==3 goto tie
- win
set /a won+=1 echo Player wins^! goto end
- loss
set /a lost+=1 echo Computer Wins^! goto end
- tie
set /a tie+=1 echo Tie^! goto end
- end
set /a games+=1 set /a freq%choice%+=1 pause goto start </lang>
BBC BASIC
<lang bbcbasic>PRINT"Welcome to the game of rock-paper-scissors" PRINT "Each player guesses one of these three, and reveals it at the same time." PRINT "Rock blunts scissors, which cut paper, which wraps stone." PRINT "If both players choose the same, it is a draw!" PRINT "When you've had enough, choose Q." DIM rps%(2),g$(3) g$()="rock","paper","scissors" total%=0 draw%=0 pwin%=0 cwin%=0 c%=RND(3) PRINT"What is your move (press R, P, or S)?" REPEAT
REPEAT q$=GET$ UNTIL INSTR("RPSrpsQq",q$)>0
g%=(INSTR("RrPpSsQq",q$)-1) DIV 2
IF g%>2 THEN PROCsummarise:END
total%+=1
rps%(g%)+=1
PRINT"You chose ";g$(g%);" and I chose ";g$(c%);
CASE g%-c% OF
WHEN 0:
PRINT ". It's a draw"
draw%+=1
WHEN 1,-2:
PRINT ". You win!"
pwin%+=1
WHEN -1,2:
PRINT ". I win!"
cwin%+=1
ENDCASE
c%=FNmove(rps%(),total%)
UNTIL FALSE END
DEFPROCsummarise PRINT "You won ";pwin%;", and I won ";cwin%;". There were ";draw%;" draws" PRINT "Thanks for playing!" ENDPROC
DEFFNmove(p%(),t%) LOCAL r% r%=RND(total%) IF r%<=p%(0) THEN =1 IF r%<=p%(0)+p%(1) THEN =2 =0</lang>
Sample output:
Welcome to the game of rock-paper-scissors Each player guesses one of these three, and reveals it at the same time. Rock blunts scissors, which cut paper, which wraps stone. If both players choose the same, it is a draw! When you've had enough, choose Q. What is your move (press R, P, or S)? You chose rock and I chose paper. I win! You chose scissors and I chose paper. You win! You chose scissors and I chose paper. You win! You chose scissors and I chose paper. You win! You chose scissors and I chose paper. You win! You chose scissors and I chose rock. I win! You chose paper and I chose paper. It's a draw You chose paper and I chose rock. You win! You chose paper and I chose rock. You win! You chose paper and I chose paper. It's a draw You chose paper and I chose paper. It's a draw You chose paper and I chose rock. You win! You chose scissors and I chose rock. I win! You chose scissors and I chose scissors. It's a draw You chose scissors and I chose rock. I win! You chose scissors and I chose scissors. It's a draw You chose scissors and I chose rock. I win! You won 7, and I won 5. There were 5 draws Thanks for playing!
C
<lang C>
- include <stdio.h>
- include <stdlib.h>
- define LEN 3
/* pick a random index from 0 to n-1, according to probablities listed
in p[] which is assumed to have a sum of 1. The values in the probablity list matters up to the point where the sum goes over 1 */
int rand_idx(double *p, int n) { double s = rand() / (RAND_MAX + 1.0); int i; for (i = 0; i < n - 1 && (s -= p[i]) >= 0; i++); return i; }
int main() { int user_action, my_action; int user_rec[] = {0, 0, 0}; const char *names[] = { "Rock", "Paper", "Scissors" }; char str[2]; const char *winner[] = { "We tied.", "Meself winned.", "You win." }; double p[LEN] = { 1./3, 1./3, 1./3 };
while (1) { my_action = rand_idx(p,LEN);
printf("\nYour choice [1-3]:\n" " 1. Rock\n 2. Paper\n 3. Scissors\n> ");
/* scanf is a terrible way to do input. should use stty and keystrokes */ if (!scanf("%d", &user_action)) { scanf("%1s", str); if (*str == 'q') { printf("Your choices [rock : %d , paper : %d , scissors %d] ",user_rec[0],user_rec[1], user_rec[2]); return 0; } continue; } user_action --; if (user_action > 2 || user_action < 0) { printf("invalid choice; again\n"); continue; } printf("You chose %s; I chose %s. %s\n", names[user_action], names[my_action], winner[(my_action - user_action + 3) % 3]);
user_rec[user_action]++; } } </lang>
Here's another code: (Does it using a while loop) <lang C>
- include <stdio.h> // Standard IO
- include <stdlib.h> // other stuff
- include <time.h>
- include <string.h>
//This should add weighted random function to "The Elite Noob"'s code, stolen from above code because it does calculation so well //closest I could make it to original but without pointless attempt to make code look smaller than above code by putting code on the same lines
int rand_i(int n) { int rand_max = RAND_MAX - (RAND_MAX % n); int ret; while ((ret = rand()) >= rand_max); return ret/(rand_max / n); }
int weighed_rand(int *tbl, int len) { int i, sum, r; for (i = 0, sum = 0; i < len; sum += tbl[i++]); if (!sum) return rand_i(len);
r = rand_i(sum) + 1; for (i = 0; i < len && (r -= tbl[i]) > 0; i++); return i; }
int main(int argc, const char *argv[]) { char umove[10], cmove[10], line[255]; int user, comp; int tbl[]={0,0,0}; int tbllen=3; printf("Hello, Welcome to rock-paper-scissors\nBy The Elite Noob\n"); mainloop: while(1) { // infinite loop :) printf("\n\nPlease type in 1 for Rock, 2 For Paper, 3 for Scissors, 4 to quit\n"); srand(time(NULL)); comp = (weighed_rand(tbl, tbllen) + 1) % 3; fgets(line, sizeof(line), stdin); while(sscanf(line, "%d", &user) != 1) //1 match of defined specifier on input line {
printf("You have not entered an integer.\n");
fgets(line, sizeof(line), stdin); } if( (user > 4) || (user < 1) ) { printf("Please enter a valid number!\n"); continue; } switch (comp) { case 1 : strcpy(cmove, "Rock"); break; case 2 : strcpy(cmove, "Paper"); break; case 3 : strcpy(cmove, "Scissors"); break; default : printf("Computer Error, set comp=1\n"); comp=1; strcpy(cmove, "Rock"); break; } switch (user) { case 1 : strcpy(umove, "Rock"); break; case 2 : strcpy(umove, "Paper"); break; case 3 : strcpy(umove, "Scissors"); break; case 4 : printf("Goodbye! Thanks for playing!\n"); return 0; default : printf("Error, user number not between 1-4 exiting..."); goto mainloop; } if( (user+1)%3 == comp ) { printf("Comp Played: %s\nYou Played: %s\nSorry, You Lost!\n", cmove, umove); } else if(comp == user) { printf("Comp Played: %s\nYou Played: %s\nYou Tied :p\n", cmove, umove); } else { printf("Comp Played: %s\nYou Played: %s\nYay, You Won!\n", cmove, umove); } tbl[user-1]++; } } </lang>
C++
Version using Additional Weapons
<lang cpp>
- include <windows.h>
- include <iostream>
- include <string>
//------------------------------------------------------------------------------- using namespace std;
//------------------------------------------------------------------------------- enum choices { ROCK, SPOCK, PAPER, LIZARD, SCISSORS, MX_C }; enum indexes { PLAYER, COMPUTER, DRAW };
//------------------------------------------------------------------------------- class stats { public:
stats() : _draw( 0 )
{
ZeroMemory( _moves, sizeof( _moves ) );
ZeroMemory( _win, sizeof( _win ) );
}
void draw() { _draw++; }
void win( int p ) { _win[p]++; }
void move( int p, int m ) { _moves[p][m]++; }
int getMove( int p, int m ) { return _moves[p][m]; }
string format( int a )
{
char t[32]; wsprintf( t, "%.3d", a ); string d( t ); return d;
}
void print()
{
string d = format( _draw ),
pw = format( _win[PLAYER] ), cw = format( _win[COMPUTER] ), pr = format( _moves[PLAYER][ROCK] ), cr = format( _moves[COMPUTER][ROCK] ),
pp = format( _moves[PLAYER][PAPER] ), cp = format( _moves[COMPUTER][PAPER] ),
ps = format( _moves[PLAYER][SCISSORS] ), cs = format( _moves[COMPUTER][SCISSORS] ), pl = format( _moves[PLAYER][LIZARD] ), cl = format( _moves[COMPUTER][LIZARD] ), pk = format( _moves[PLAYER][SPOCK] ), ck = format( _moves[COMPUTER][SPOCK] );
system( "cls" ); cout << endl; cout << "+----------+-------+--------+--------+---------+----------+--------+---------+" << endl; cout << "| | WON | DRAW | ROCK | PAPER | SCISSORS | LIZARD | SPOCK |" << endl; cout << "+----------+-------+--------+--------+---------+----------+--------+---------+" << endl; cout << "| PLAYER | " << pw << " | | " << pr << " | " << pp << " | " << ps << " | " << pl << " | " << pk << " |" << endl; cout << "+----------+-------+ " << d << " +--------+---------+----------+--------+---------+" << endl; cout << "| COMPUTER | " << cw << " | | " << cr << " | " << cp << " | " << cs << " | " << cl << " | " << ck << " |" << endl; cout << "+----------+-------+--------+--------+---------+----------+--------+---------+" << endl; cout << endl << endl;
system( "pause" );
}
private:
int _moves[2][MX_C], _win[2], _draw;
}; //------------------------------------------------------------------------------- class rps { private:
int makeMove()
{
int total = 0, r, s; for( int i = 0; i < MX_C; total += statistics.getMove( PLAYER, i++ ) ); r = rand() % total;
for( int i = ROCK; i < SCISSORS; i++ ) { s = statistics.getMove( PLAYER, i ); if( r < s ) return ( i + 1 ); r -= s; }
return ROCK;
}
void printMove( int p, int m )
{
if( p == COMPUTER ) cout << "My move: "; else cout << "Your move: ";
switch( m ) { case ROCK: cout << "ROCK\n"; break; case PAPER: cout << "PAPER\n"; break; case SCISSORS: cout << "SCISSORS\n"; break; case LIZARD: cout << "LIZARD\n"; break; case SPOCK: cout << "SPOCK\n"; }
}
public:
rps()
{
checker[ROCK][ROCK] = 2; checker[ROCK][PAPER] = 1; checker[ROCK][SCISSORS] = 0; checker[ROCK][LIZARD] = 0; checker[ROCK][SPOCK] = 1; checker[PAPER][ROCK] = 0; checker[PAPER][PAPER] = 2; checker[PAPER][SCISSORS] = 1; checker[PAPER][LIZARD] = 1; checker[PAPER][SPOCK] = 0; checker[SCISSORS][ROCK] = 1; checker[SCISSORS][PAPER] = 0; checker[SCISSORS][SCISSORS] = 2; checker[SCISSORS][LIZARD] = 0; checker[SCISSORS][SPOCK] = 1; checker[LIZARD][ROCK] = 1; checker[LIZARD][PAPER] = 0; checker[LIZARD][SCISSORS] = 1; checker[LIZARD][LIZARD] = 2; checker[LIZARD][SPOCK] = 0; checker[SPOCK][ROCK] = 0; checker[SPOCK][PAPER] = 1; checker[SPOCK][SCISSORS] = 0; checker[SPOCK][LIZARD] = 1; checker[SPOCK][SPOCK] = 2;
}
void play()
{
int p, r, m; while( true ) { cout << "What is your move (1)ROCK (2)SPOCK (3)PAPER (4)LIZARD (5)SCISSORS (0)Quit ? "; cin >> p; if( !p || p < 0 ) break; if( p > 0 && p < 6 ) { p--; cout << endl; printMove( PLAYER, p ); statistics.move( PLAYER, p );
m = makeMove(); statistics.move( COMPUTER, m ); printMove( COMPUTER, m );
r = checker[p][m]; switch( r ) { case DRAW: cout << endl << "DRAW!" << endl << endl; statistics.draw(); break; case COMPUTER: cout << endl << "I WIN!" << endl << endl; statistics.win( COMPUTER ); break; case PLAYER: cout << endl << "YOU WIN!" << endl << endl; statistics.win( PLAYER );
} system( "pause" ); } system( "cls" ); } statistics.print();
}
private:
stats statistics; int checker[MX_C][MX_C];
}; //------------------------------------------------------------------------------- int main( int argc, char* argv[] ) {
srand( GetTickCount() ); rps game; game.play(); return 0;
} //------------------------------------------------------------------------------- </lang>
Sample output:
What is your move (1)ROCK (2)SPOCK (3)PAPER (4)LIZARD (5)SCISSORS (0)Quit ? 1 Your move: ROCK My move: PAPER I WIN! What is your move (1)ROCK (2)SPOCK (3)PAPER (4)LIZARD (5)SCISSORS (0)Quit ? 3 Your move: PAPER My move: SPOCK YOU WIN! What is your move (1)ROCK (2)SPOCK (3)PAPER (4)LIZARD (5)SCISSORS (0)Quit ? 1 Your move: SPOCK My move: LIZARD I WIN! [...] +----------+-------+--------+--------+---------+----------+--------+---------+ | | WON | DRAW | ROCK | PAPER | SCISSORS | LIZARD | SPOCK | +----------+-------+--------+--------+---------+----------+--------+---------+ | PLAYER | 001 | | 003 | 002 | 000 | 000 | 009 | +----------+-------+ 005 +--------+---------+----------+--------+---------+ | COMPUTER | 008 | | 000 | 005 | 000 | 001 | 008 | +----------+-------+--------+--------+---------+----------+--------+---------+
C#
<lang c sharp>using System; using System.Collections.Generic; using System.Linq;
namespace RockPaperScissors {
class Program
{
static void Main(string[] args)
{
// There is no limit on the amount of weapons supported by RPSGame. Matchups are calculated depending on the order.
var rps = new RPSGame("scissors", "paper", "rock", "lizard", "spock");
int wins = 0, losses = 0, draws = 0;
while (true)
{
Console.WriteLine("Make your move: " + string.Join(", ", rps.Weapons) + ", quit");
string weapon = Console.ReadLine().Trim().ToLower();
if (weapon == "quit")
break;
if (!rps.Weapons.Contains(weapon))
{
Console.WriteLine("Invalid weapon!");
continue;
}
int result = rps.Next(weapon);
Console.WriteLine("You chose {0} and your opponent chose {1}!", weapon, rps.LastAIWeapon);
switch (result)
{
case 1: Console.WriteLine("{0} pwns {1}. You're a winner!", weapon, rps.LastAIWeapon);
wins++;
break;
case 0: Console.WriteLine("Draw!");
draws++;
break;
case -1: Console.WriteLine("{0} pwns {1}. You're a loser!", rps.LastAIWeapon, weapon);
losses++;
break;
}
Console.WriteLine();
}
Console.WriteLine("\nPlayer Statistics\nWins: {0}\nLosses: {1}\nDraws: {2}", wins, losses, draws);
}
class RPSGame
{
public RPSGame(params string[] weapons)
{
Weapons = weapons;
// Creates a new AI opponent, and gives it the list of weapons.
_rpsAI = new RPSAI(weapons);
}
// Play next turn.
public int Next(string weapon)
{
string aiWeapon = _rpsAI.NextMove(); // Gets the AI opponent's next move.
LastAIWeapon = aiWeapon; // Saves the AI opponent's move in a property so the player can see it.
_rpsAI.AddPlayerMove(weapon); // Let the AI know which weapon the player chose, for future predictions.
return GetWinner(Weapons, weapon, aiWeapon); // Returns -1 if AI win, 0 if draw, and 1 if player win.
}
// Returns matchup winner.
public static int GetWinner(string[] weapons, string weapon1, string weapon2)
{
if (weapon1 == weapon2)
return 0; // If weapons are the same, return 0 for draw.
if (GetVictories(weapons, weapon1).Contains(weapon2))
return 1; // Returns 1 for weapon1 win.
else if (GetVictories(weapons, weapon2).Contains(weapon1))
return -1; // Returns -1 for weapon2 win.
throw new Exception("No winner found.");
}
/*
* Return weapons that the provided weapon beats.
* The are calculated in the following way:
* If the index of the weapon is even, then all even indices less than it,
* and all odd indices greater than it, are victories.
* One exception is if it is an odd index, and also the last index in the set,
* then the first index in the set is a victory.
*/
public static IEnumerable<string> GetVictories(string[] weapons, string weapon)
{
// Gets index of weapon.
int index = Array.IndexOf(weapons, weapon);
// If weapon is odd and the final index in the set, then return the first item in the set as a victory.
if (index % 2 != 0 && index == weapons.Length - 1)
yield return weapons[0];
for (int i = index - 2; i >= 0; i -= 2)
yield return weapons[i];
for (int i = index + 1; i < weapons.Length; i += 2)
yield return weapons[i];
}
public string LastAIWeapon
{
private set;
get;
}
public readonly string[] Weapons;
private RPSAI _rpsAI;
class RPSAI
{
public RPSAI(params string[] weapons)
{
_weapons = weapons;
_weaponProbability = new Dictionary<string, int>();
// The AI sets the probability for each weapon to be chosen as 1.
foreach (string weapon in weapons)
_weaponProbability.Add(weapon, 1);
_random = new Random();
}
// Increases probability of selecting each weapon that beats the provided move.
public void AddPlayerMove(string weapon)
{
int index = Array.IndexOf(_weapons, weapon);
foreach (string winWeapon in _weapons.Except(GetVictories(_weapons, weapon)))
if (winWeapon != weapon)
_weaponProbability[winWeapon]++;
}
// Gets the AI's next move.
public string NextMove()
{
double r = _random.NextDouble();
double divisor = _weaponProbability.Values.Sum();
var weightedWeaponRanges = new Dictionary<double, string>();
double currentPos = 0.0;
// Maps probabilities to ranges between 0.0 and 1.0. Returns weighted random weapon.
foreach (var weapon in _weaponProbability)
{
double weightedRange = weapon.Value / divisor;
if (r <= currentPos + (weapon.Value / divisor))
return weapon.Key;
currentPos += weightedRange;
}
throw new Exception("Error calculating move.");
}
Random _random;
private readonly string[] _weapons;
private Dictionary<string, int> _weaponProbability;
}
}
}
}</lang>
Sample output of first 2 and last 2 rounds when player chooses rock every turn:
Make your move: scissors, paper, rock, lizard, spock, quit rock You chose rock and your opponent chose lizard! rock pwns lizard. You're a winner! Make your move: scissors, paper, rock, lizard, spock, quit rock You chose rock and your opponent chose lizard! rock pwns lizard. You're a winner! ... Make your move: scissors, paper, rock, lizard, spock, quit rock You chose rock and your opponent chose paper! paper pwns rock. You're a loser! Make your move: scissors, paper, rock, lizard, spock, quit rock You chose rock and your opponent chose spock! spock pwns rock. You're a loser! Make your move: scissors, paper, rock, lizard, spock, quit quit Player Statistics Wins: 5 Losses: 60 Draws: 1
Clojure
Note: If you run it with Leiningen, use the special trampoline run to prevent issues:
$ lein trampoline run
Code:
<lang clojure>(ns rps.core
(:require [clojure.data.generators :refer [weighted]]) (:import jline.Terminal) (:gen-class))
(def what-beats {:rock :paper, :paper :scissors, :scissors :rock})
(defn battle [human comp]
(let [h (name human)
c (name comp)]
(cond
(= human comp) (println (format "We both picked %s. DRAW!" c))
(= human (what-beats comp))
(println (format "Your %s defeats computer's %s. YOU WIN!" h c))
(= comp (what-beats human))
(println (format "Computer's %s defeats your %s. YOU LOSE!" c h))
:else (println (format "Wat? %s and %s ?" h c)))))
(defn key->rps [k]
(cond (or (= k 82) (= k 114)) :rock (or (= k 80) (= k 112)) :paper (or (= k 83) (= k 115)) :scissors :else nil))
(defn play-game [freqs]
(println "\n(R)ock, (P)aper, (S)cissors?")
(let [term (Terminal/getTerminal)
rps (key->rps (.readCharacter term System/in))]
(if-not (nil? rps)
(do
(battle rps (what-beats (weighted freqs)))
(recur (assoc freqs rps (inc (rps freqs)))))
(println "Game Over Man! Game Over!"))))
(defn -main
"Rock, Paper, Scissors!"
[& args]
(play-game {:rock 1, :paper 1, :scissors 1}))</lang>
- Output:
(R)ock, (P)aper, (S)cissors? Your paper defeats computer's rock. YOU WIN! (R)ock, (P)aper, (S)cissors? Computer's paper defeats your rock. YOU LOSE! (R)ock, (P)aper, (S)cissors? We both picked scissors. DRAW!
Crystal
Inspired by #Ruby solution, but improved to allow additional weapons <lang ruby>
- conventional weapons
enum Choice
Rock Paper Scissors
end
BEATS = {
Choice::Rock => [Choice::Paper], Choice::Paper => [Choice::Scissors], Choice::Scissors => [Choice::Rock],
}
- uncomment to use additional weapons
- enum Choice
- Rock
- Paper
- Scissors
- Lizard
- Spock
- end
- BEATS = {
- Choice::Rock => [Choice::Paper, Choice::Spock],
- Choice::Paper => [Choice::Scissors, Choice::Lizard],
- Choice::Scissors => [Choice::Rock, Choice::Spock],
- Choice::Lizard => [Choice::Rock, Choice::Scissors],
- Choice::Spock => [Choice::Paper, Choice::Lizard],
- }
class RPSAI
@stats = {} of Choice => Int32
def initialize
Choice.values.each do |c|
@stats[c] = 1
end
end
def choose
v = rand(@stats.values.sum)
@stats.each do |choice, rate|
v -= rate
return choice if v < 0
end
raise ""
end
def train(selected)
BEATS[selected].each do |c|
@stats[c] += 1
end
end
end
enum GameResult
HumanWin ComputerWin Draw
def to_s
case self
when .draw?
"Draw"
when .human_win?
"You win!"
when .computer_win?
"I win!"
end
end
end
class RPSGame
@score = Hash(GameResult, Int32).new(0) @ai = RPSAI.new
def check(player, computer) return GameResult::ComputerWin if BEATS[player].includes? computer return GameResult::HumanWin if BEATS[computer].includes? player return GameResult::Draw end
def round
puts ""
print "Your choice (#{Choice.values.join(", ")}):"
s = gets.not_nil!.strip.downcase
return false if "quit".starts_with? s
player_turn = Choice.values.find { |choice| choice.to_s.downcase.starts_with? s }
unless player_turn
puts "Invalid choice"
return true
end
ai_turn = @ai.choose
result = check(player_turn, ai_turn)
puts "H: #{player_turn}, C: #{ai_turn} => #{result}"
@score[result] += 1
puts "score: human=%d, computer=%d, draw=%d" % GameResult.values.map { |r| @score[r] }
@ai.train player_turn
true
end
end
game = RPSGame.new loop do
break unless game.round
end</lang>
D
<lang d>import std.stdio, std.random, std.string, std.conv, std.array, std.typecons;
enum Choice { rock, paper, scissors }
bool beats(in Choice c1, in Choice c2) pure nothrow @safe @nogc {
with (Choice) return (c1 == paper && c2 == rock) ||
(c1 == scissors && c2 == paper) ||
(c1 == rock && c2 == scissors);
}
Choice genMove(in int r, in int p, in int s) @safe /*@nogc*/ {
immutable x = uniform!"[]"(1, r + p + s); if (x < s) return Choice.rock; if (x <= s + r) return Choice.paper; else return Choice.scissors;
}
Nullable!To maybeTo(To, From)(From x) pure nothrow @safe {
try {
return typeof(return)(x.to!To);
} catch (ConvException) {
return typeof(return)();
} catch (Exception e) {
static immutable err = new Error("std.conv.to failure");
throw err;
}
}
void main() /*@safe*/ {
int r = 1, p = 1, s = 1;
while (true) {
write("rock, paper or scissors? ");
immutable hs = readln.strip.toLower;
if (hs.empty)
break;
immutable h = hs.maybeTo!Choice;
if (h.isNull) {
writeln("Wrong input: ", hs);
continue;
}
immutable c = genMove(r, p, s);
writeln("Player: ", h.get, " Computer: ", c);
if (beats(h, c)) writeln("Player wins\n");
else if (beats(c, h)) writeln("Player loses\n");
else writeln("Draw\n");
final switch (h.get) {
case Choice.rock: r++; break;
case Choice.paper: p++; break;
case Choice.scissors: s++; break;
}
}
}</lang>
- Output:
rock, paper or scissors? paper Player: paper Computer: paper Draw rock, paper or scissors? scissors Player: scissors Computer: scissors Draw rock, paper or scissors? rock Player: rock Computer: paper Player loses rock, paper or scissors? rock Player: rock Computer: paper Player loses rock, paper or scissors?
Elixir
<lang elixir>defmodule Rock_paper_scissors do
def play, do: loop([1,1,1])
defp loop([r,p,s]=odds) do
IO.gets("What is your move? (R,P,S,Q) ") |> String.upcase |> String.first
|> case do
"Q" -> IO.puts "Good bye!"
human when human in ["R","P","S"] ->
IO.puts "Your move is #{play_to_string(human)}."
computer = select_play(odds)
IO.puts "My move is #{play_to_string(computer)}"
case beats(human,computer) do
true -> IO.puts "You win!"
false -> IO.puts "I win!"
_ -> IO.puts "Draw"
end
case human do
"R" -> loop([r+1,p,s])
"P" -> loop([r,p+1,s])
"S" -> loop([r,p,s+1])
end
_ ->
IO.puts "Invalid play"
loop(odds)
end
end
defp beats("R","S"), do: true
defp beats("P","R"), do: true
defp beats("S","P"), do: true
defp beats(x,x), do: :draw
defp beats(_,_), do: false
defp play_to_string("R"), do: "Rock"
defp play_to_string("P"), do: "Paper"
defp play_to_string("S"), do: "Scissors"
defp select_play([r,p,s]) do
n = :rand.uniform(r+p+s)
cond do
n <= r -> "P"
n <= r+p -> "S"
true -> "R"
end
end
end
Rock_paper_scissors.play</lang>
Sample output:
What is your move? (R,P,S,Q) r Your move is Rock. My move is Scissors You win! What is your move? (R,P,S,Q) p Your move is Paper. My move is Paper Draw What is your move? (R,P,S,Q) s Your move is Scissors. My move is Scissors Draw What is your move? (R,P,S,Q) q Good bye!
Erlang
<lang erlang> -module(rps). -compile(export_all).
play() ->
loop([1,1,1]).
loop([R,P,S]=Odds) ->
case io:fread("What is your move? (R,P,S,Q) ","~c") of
{ok,["Q"]} -> io:fwrite("Good bye!~n");
{ok,Human} when Human == $R; Human == $P; Human == $S ->
io:fwrite("Your move is ~s.~n",
[play_to_string(Human)]),
Computer = select_play(Odds),
io:fwrite("My move is ~s~n",
[play_to_string(Computer)]),
case {beats(Human,Computer),beats(Computer,Human)} of
{true,_} -> io:fwrite("You win!~n");
{_,true} -> io:fwrite("I win!~n");
_ -> io:fwrite("Draw~n")
end,
case Human of
$R -> loop([R+1,P,S]);
$P -> loop([R,P+1,S]);
$S -> loop([R,P,S+1])
end;
_ ->
io:fwrite("Invalid play~n"),
loop(Odds)
end.
beats($R,$S) -> true; beats($P,$R) -> true; beats($S,$P) -> true; beats(_,_) -> false.
play_to_string($R) -> "Rock"; play_to_string($P) -> "Paper"; play_to_string($S) -> "Scissors".
select_play([R,P,S]) ->
N = random:uniform(R+P+S),
if
N =< R -> $P;
N =< R+P -> $S;
true -> $R
end.
</lang>
Euphoria
<lang euphoria>function weighted_rand(sequence table)
integer sum,r
sum = 0
for i = 1 to length(table) do
sum += table[i]
end for
r = rand(sum)
for i = 1 to length(table)-1 do
r -= table[i]
if r <= 0 then
return i
end if
end for
return length(table)
end function
constant names = { "Rock", "Paper", "Scissors" } constant winner = { "We tied.", "Meself winned.", "You win." } integer user_action, my_action, key, win sequence user_rec, score user_rec = {1,1,1} score = {0,0}
while 1 do
my_action = remainder(weighted_rand(user_rec)+1,3)+1
puts(1,"Your choice [1-3]:\n")
puts(1," 1. Rock\n 2. Paper\n 3. Scissors\n> ")
key = -1
while (key < '1' or key > '3') and key != 'q' do
key = get_key()
end while
puts(1,key)
puts(1,'\n')
if key = 'q' then
exit
end if
user_action = key-'0'
win = remainder(my_action-user_action+3,3)
printf(1,"You chose %s; I chose %s. %s\n",
{ names[user_action],
names[my_action],
winner[win+1] })
if win then
score[win] += 1
end if
printf(1,"\nScore %d:%d\n",score)
user_rec[user_action] += 1
end while</lang>
F#
<lang FSharp>open System
let random = Random () let rand = random.NextDouble () //Gets a random number in the range (0.0, 1.0)
/// Union of possible choices for a round of rock-paper-scissors type Choice = | Rock | Paper | Scissors
/// Gets the string representation of a Choice let getString = function
| Rock -> "Rock" | Paper -> "Paper" | Scissors -> "Scissors"
/// Defines rules for winning and losing let beats (a : Choice, b : Choice) =
match a, b with | Rock, Scissors -> true // Rock beats Scissors | Paper, Rock -> true // Paper beats Rock | Scissors, Paper -> true // Scissors beat Paper | _, _ -> false
/// Generates the next move for the computer based on probability derived from previous player moves. let genMove r p s =
let tot = r + p + s let n = rand if n <= s / tot then Rock elif n <= (s + r) / tot then Paper else Scissors
/// Gets the move chosen by the player let rec getMove () =
printf "[R]ock, [P]aper, or [S]cissors?: "
let choice = Console.ReadLine ()
match choice with
| "r" | "R" -> Rock
| "p" | "P" -> Paper
| "s" | "S" -> Scissors
| _ ->
printf "Invalid choice.\n\n"
getMove ()
/// Place where all the game logic takes place. let rec game (r : float, p : float, s : float) =
let comp = genMove r p s
let player = getMove ()
Console.WriteLine ("Player: {0} vs Computer: {1}", getString player, getString comp)
Console.WriteLine (
if beats(player, comp) then "Player Wins!\n"
elif beats(comp, player) then "Computer Wins!\n"
else "Draw!\n"
)
let nextR = if player = Rock then r + 1.0 else r
let nextP = if player = Paper then p + 1.0 else p
let nextS = if player = Scissors then s + 1.0 else s
game (nextR, nextP, nextS)
game(1.0, 1.0, 1.0) </lang>
Factor
<lang factor>USING: combinators formatting io kernel math math.ranges qw random sequences ; IN: rosetta-code.rock-paper-scissors
CONSTANT: thing qw{ rock paper scissors } CONSTANT: msg { "I win." "Tie!" "You win." }
- ai-choice ( r p s -- n )
3dup + + nip [1,b] random {
{ [ 3dup nip >= ] [ 3drop 1 ] }
{ [ 3dup [ + ] dip >= ] [ 3drop 2 ] }
[ 3drop 0 ]
} cond ;
- player-choice ( -- n )
"r/p/s/q? " write readln qw{ r p s q } index dup
[ drop player-choice ] unless ;
! return: ! -1 for n1 loses to n2. ! 0 for n1 ties n2. ! 1 for n1 beats n2.
- outcome ( n1 n2 -- n3 ) - dup abs 1 > [ neg ] when sgn ;
- status. ( seq -- )
"My wins: %d Ties: %d Your wins: %d\n" vprintf ;
- choices. ( n1 n2 -- )
[ thing nth ] bi@ "You chose: %s\nI chose: %s\n" printf ;
- tally ( seq n -- seq' ) over [ 1 + ] change-nth ;
- game ( seq -- seq' )
dup status. player-choice dup 3 = [ drop ] [
[ 3 + tally ] keep over 3 tail* first3 ai-choice 2dup
choices. outcome 1 + dup [ tally ] dip msg nth print nl
game
] if ;
! The game state is a sequence where the members are: ! losses, ties, wins, #rock, #paper, #scissors
- main ( -- ) { 0 0 0 1 1 1 } clone game drop ;
MAIN: main</lang>
- Output:
My wins: 0 Ties: 0 Your wins: 0 r/p/s/q? r You chose: rock I chose: paper I win. My wins: 1 Ties: 0 Your wins: 0 r/p/s/q? r You chose: rock I chose: scissors You win. My wins: 1 Ties: 0 Your wins: 1 r/p/s/q? r You chose: rock I chose: paper I win. My wins: 2 Ties: 0 Your wins: 1 r/p/s/q? r You chose: rock I chose: rock Tie! My wins: 2 Ties: 1 Your wins: 1 r/p/s/q? r You chose: rock I chose: rock Tie! My wins: 2 Ties: 2 Your wins: 1 r/p/s/q? r You chose: rock I chose: paper I win. My wins: 3 Ties: 2 Your wins: 1 r/p/s/q? r You chose: rock I chose: paper I win. My wins: 4 Ties: 2 Your wins: 1 r/p/s/q? q
Fortran
Please find an example run in a GNU/linux system along with compilation instructions at the beginning of the FORTRAN 2008 source code. Following the source are examples demonstrating the effectiveness of the built in simple predictive artificial intelligence. It uses the yes utility for a constant data source. <lang FORTRAN> ! compilation ! gfortran -std=f2008 -Wall -ffree-form -fall-intrinsics -fimplicit-none f.f08 -o f ! ! EXAMPLE ! !$ ./f !rock, paper, scissors? papier !scoring computer choice (r) and your choice (p) !rock, paper, scissors? sizzerz !scoring computer choice (s) and your choice (s) !rock, paper, scissors? quit !scoring computer choice (r) and your choice (q) ! Who's keeping score anyway??? ! 0.5 1.5 ! you won! !$
program rpsgame
integer, parameter :: COMPUTER=1, HAPLESSUSER=2
integer, dimension(3) :: rps = (/1,1,1/)
real, dimension(3) :: p
character :: answer, cc ! computer choice
integer :: exhaustion, i
real, dimension(2) :: score = (/0, 0/)
character(len=8), dimension(3) :: choices = (/'rock ','paper ','scissors'/)
real :: harvest
do exhaustion = 1, 30
p = rps/real(sum(rps))
p(2) = p(2) + p(1)
p(3) = p(3) + p(2)
call random_number(harvest)
i = sum(merge(1,0,harvest.le.p)) ! In memory of Ken Iverson, logical is more useful as integer.
cc = 'rsp'(i:i)
write(6, "(2(A,', '),A,'? ')", advance='no')(trim(choices(i)),i=1,size(choices))
read(5, *) answer
write(6, "('scoring computer choice (',A,') and your choice (',A,')')")cc,answer
if (answer.eq.cc) then
score = score + 0.5
else
i = HAPLESSUSER
if (answer.eq.'r') then
if (cc.eq.'p') i = COMPUTER
else if (answer.eq.'p') then
if (cc.eq.'s') i = COMPUTER
else if (answer.eq.'s') then
if (cc.eq.'r') i = COMPUTER
else
exit
endif
score(i) = score(i) + 1
end if
i = scan('rps',answer)
rps(i) = rps(i) + 1
end do
if (25 .lt. exhaustion) write(6, *) "I'm bored out of my skull"
write(6, *)"Who's keeping score anyway???"
write(6, '(2f5.1)') score
if (score(COMPUTER) .lt. score(HAPLESSUSER)) print*,'you won!'
end program rpsgame </lang> rpsgame won't play more than 30 games at a time. <lang bash> $ yes r | ./f # rock rock, paper, scissors? scoring computer choice (r) and your choice (r) rock, paper, scissors? scoring computer choice (s) and your choice (r) rock, paper, scissors? scoring computer choice (r) and your choice (r) ... rock, paper, scissors? scoring computer choice (p) and your choice (r)
I'm bored out of my skull Who's keeping score anyway??? 25.5 4.5
yes: standard output: Broken pipe yes: write error $ yes p 2>/dev/null | ./f # paper rock, paper, scissors? scoring computer choice (r) and your choice (p) rock, paper, scissors? scoring computer choice (s) and your choice (p) rock, paper, scissors? scoring computer choice (r) and your choice (p) rock, paper, scissors? scoring computer choice (s) and your choice (p) ... rock, paper, scissors? scoring computer choice (s) and your choice (p)
I'm bored out of my skull Who's keeping score anyway??? 25.5 4.5
$ yes scissors 2>/dev/null | ./f # scissors rock, paper, scissors? scoring computer choice (r) and your choice (s) rock, paper, scissors? scoring computer choice (r) and your choice (s) ... rock, paper, scissors? scoring computer choice (r) and your choice (s)
I'm bored out of my skull Who's keeping score anyway??? 26.5 3.5
$ </lang>
GlovePIE
You can only press the R, P or S key to advance. <lang glovepie>if var.end=0 then var.end=0 var.computerchoice=random(3) // 1 is rock, 2 is paper, and 3 is scissors. debug="Press the R key for rock, the P key for paper, or the S key for scissors:" endif if pressed(Key.R)and var.end=0 then
var.end=1
if var.computerchoice=1 then
debug="You chose rock, which the computer also chose, so it's a tie!"
else
if var.computerchoice=2 then
debug="The computer chose paper, covering your choice of rock, so you lose!"
else
debug="You chose rock, smashing the computer's choice of scissors, so you win!"
endif
endif
endif if pressed(Key.P)and var.end=0 then
var.end=1
if var.computerchoice=1 then
debug="You chose paper, covering the computer's choice of rock, so you win!"
else
if var.computerchoice=2 then
debug="You chose paper, which the computer also chose, so it's a tie!"
else
debug="The computer chose scissors, cutting your choice of paper, so you lose!"
endif
endif
endif if pressed(Key.S)and var.end=0 then
var.end=1
if var.computerchoice=1 then
debug="The computer chose rock, smashing your choice of scissors, so you lose!"
else
if var.computerchoice=2 then
debug="You chose scissors, cutting the computer's choice of paper, so you win!"
else
debug="You chose scissors, which the computer also chose, so it's a tie!"
endif
endif
endif</lang>
Go
<lang go>package main
import (
"fmt" "math/rand" "strings" "time"
)
const rps = "rps"
var msg = []string{
"Rock breaks scissors", "Paper covers rock", "Scissors cut paper",
}
func main() {
rand.Seed(time.Now().UnixNano())
fmt.Println("Rock Paper Scissors")
fmt.Println("Enter r, p, or s as your play. Anything else ends the game.")
fmt.Println("Running score shown as <your wins>:<my wins>")
var pi string // player input
var aScore, pScore int
sl := 3 // for output alignment
pcf := make([]int, 3) // pcf = player choice frequency
var plays int
aChoice := rand.Intn(3) // ai choice for first play is completely random
for {
// get player choice
fmt.Print("Play: ")
_, err := fmt.Scanln(&pi) // lazy
if err != nil || len(pi) != 1 {
break
}
pChoice := strings.Index(rps, pi)
if pChoice < 0 {
break
}
pcf[pChoice]++
plays++
// show result of play
fmt.Printf("My play:%s%c. ", strings.Repeat(" ", sl-2), rps[aChoice])
switch (aChoice - pChoice + 3) % 3 {
case 0:
fmt.Println("Tie.")
case 1:
fmt.Printf("%s. My point.\n", msg[aChoice])
aScore++
case 2:
fmt.Printf("%s. Your point.\n", msg[pChoice])
pScore++
}
// show score
sl, _ = fmt.Printf("%d:%d ", pScore, aScore)
// compute ai choice for next play
switch rn := rand.Intn(plays); {
case rn < pcf[0]:
aChoice = 1
case rn < pcf[0]+pcf[1]:
aChoice = 2
default:
aChoice = 0
}
}
}</lang>
- Sample output:
Rock Paper Scissors Enter r, p, or s as your play. Anything else ends the game. Running score shown as <your wins>:<my wins> Play: r My play: r. Tie. 0:0 Play: p My play: p. Tie. 0:0 Play: s My play: p. Scissors cut paper. Your point. 1:0 Play: r My play: p. Paper covers rock. My point. 1:1 Play: r My play: r. Tie. 1:1 Play: r My play: p. Paper covers rock. My point. 1:2 Play:
Additional weapons: <lang go>package main
import (
"flag" "fmt" "log" "math/rand" "regexp" "strings" "time"
"github.com/BurntSushi/toml"
)
var help = `rps plays rock-paper-scissors with optional addition weapons.
Usage: rps [-h] [game]
-h display help. game is a game description file in TOML (https://github.com/mojombo/toml).
The traditional game can be described as
title = "Rock Paper Scissors" win = [
"rock breaks scissors", "paper covers rock", "scissors cut paper",
]
The title is optional, it just prints out at the beginning of a game.
The "win" list is statments where the first word wins over the last word.
It's case sensitive so make things easy by using consistent case. Don't use punctuation, at least not next to a first or last word.
Additionally, you can have a "lose" key where the first word loses to the the last, for example
lose = ["rock falls into well"]
To organize things with additional weapons, you can just use the winning weapon with a list of clauses, for example
lizard = ["poisons Spock", "eats paper"]
The progam ignores anything in parentheses when identifying first or last words. Examples (from RPS-101) with weapons gun, fire, and sword,
win = [
"gun fire(s)" "(flaming) sword has fire"
]
Finally, TOML is a hash, so don't duplicate keys. That means no multiple win or lose keys. You must combine all the win statements and all the lose statements.`
var rps = ` title = "Rock Paper Scissors" win = [
"rock breaks scissors", "paper covers rock", "scissors cut paper",
]`
func main() {
h := flag.Bool("h", false, "show help")
flag.Parse()
if *h {
fmt.Println(help)
return
}
m := map[string]interface{}{}
var err error
switch flag.NArg() {
case 0:
_, err = toml.Decode(rps, &m)
case 1:
_, err = toml.DecodeFile(flag.Arg(0), &m)
default:
flag.Usage()
return
}
if err != nil {
log.Fatal(err)
}
play(parse(m))
}
type decision map[string]map[string]string
type fIndex map[string]int
func parse(m map[string]interface{}) (title string, f fIndex, d decision) {
d = decision{}
for k, v := range m {
switch t := v.(type) {
case []interface{}:
d.parseList(k, t)
case string:
if k == "title" {
title = t
} else {
log.Println("Unknown key:", k)
}
}
}
i := 0
f = fIndex{}
for w, wl := range d {
if _, ok := f[w]; !ok {
f[w] = i
i++
}
for l := range wl {
if _, ok := f[l]; !ok {
f[l] = i
i++
}
}
}
for fm := range f {
if _, ok := d[fm]; !ok {
log.Println("note,", fm, "always loses!")
}
}
balanced := len(f)&1 == 1
for _, l := range d {
if !balanced {
break
}
balanced = len(l)*2+1 == len(f)
}
if !balanced {
log.Print("note, game is unbalanced")
}
return title, f, d
}
var r = regexp.MustCompile(`[(].*[)]`)
func (d decision) parseList(kw string, l []interface{}) {
var ww string
for _, e := range l {
st, ok := e.(string)
if !ok {
log.Fatal("invalid", e)
}
w := strings.Fields(r.ReplaceAllLiteralString(st, ""))
if len(w) == 0 {
log.Fatalln("invalid:", kw, st)
}
lw := w[len(w)-1]
switch kw {
case "win":
ww = w[0]
case "lose":
ww, lw = lw, w[0]
default:
ww = kw
for i := 0; ; i++ {
if i == len(w) {
st = ww + " " + st
break
}
if w[i] == ww {
break
}
}
}
if lw == ww {
log.Fatalln("invalid:", st)
}
if cs, ok := d[lw][ww]; ok {
log.Fatalln("conflict:", cs, "and", st)
}
d1, ok := d[ww]
if !ok {
d1 = map[string]string{}
}
d1[lw] = st
d[ww] = d1
}
}
func play(title string, fx fIndex, d decision) {
rand.Seed(time.Now().Unix())
if len(fx) == 0 {
return
}
form := make([]string, len(fx))
for w, i := range fx {
form[i] = w
}
fmt.Println()
fmt.Println(title)
fmt.Print("Choices are ", form[0])
for _, w := range form[1:] {
fmt.Printf(", %s", w)
}
fmt.Println(".")
fmt.Println("Enter one of these choices as your play. " +
"Anything else ends the game.")
fmt.Println("Running score shown as <your wins>:<my wins>")
var pw string
var aScore, pScore int
sl := 3
wcf := make([]int, len(form))
wct := 0
ax := rand.Intn(len(form))
aw := form[ax]
for {
fmt.Print("Play: ")
_, err := fmt.Scanln(&pw)
if err != nil {
break
}
px, ok := fx[pw]
if !ok {
fmt.Println(pw, "invalid.")
break
}
for f, l := range d {
if _, ok := l[pw]; ok {
wcf[fx[f]]++
wct++
}
}
fmt.Printf("My play:%s%s.\n", strings.Repeat(" ", sl-2), aw)
ast := d[aw][pw]
pst := d[pw][aw]
switch {
case ax == px:
fmt.Println("Tie.")
case ast > "" && pst > "":
log.Fatalln("conflict: ", ast, "and", pst)
case ast > "":
fmt.Printf("%s. My point.\n", ast)
aScore++
default:
fmt.Printf("%s. Your point.\n", pst)
pScore++
}
sl, _ = fmt.Printf("%d:%d ", pScore, aScore)
ax = 0
for rn := rand.Intn(wct); ; ax++ {
if f := wcf[ax]; rn < f {
break
} else {
rn -= f
}
}
aw = form[ax]
}
}</lang> Example game files:
# example unbalanced game described with both win and lose statements
title = "Rock Paper Scissors Well"
win = [
"rock breaks scissors",
"paper covers rock",
"paper covers well",
"scissors cut paper",
]
lose = [
"rock falls into well",
"scissors fall into well",
]
# example with implied wins, parenthetical word.
title = "RPS-7"
rock = [
"pounds out fire",
"crushes scissors",
"crushes sponge",
]
fire = [
"melts scissors",
"burns paper",
"burns sponge",
]
scissors = [
"swish through air",
"cut paper",
"cut sponge",
]
sponge = [
"soaks paper",
"uses air (pockets)",
"absorbs water",
]
paper = [
"fans air",
"covers rock",
"floats on water",
]
air = [
"blows out fire",
"erodes rock",
"evaporates water",
]
water = [
"erodes rock",
"puts out fire",
"rusts scissors",
]
- Example output:
> rps rpsw 2014/05/20 20:42:03 note, game is unbalanced Rock Paper Scissors Well Choices are rock, scissors, paper, well. Enter one of these choices as your play. Anything else ends the game. Running score shown as <your wins>:<my wins> Play: rock My play: rock. Tie. 0:0 Play: well My play: paper. paper covers well. My point. 0:1 Play: scissors My play: paper. scissors cut paper. Your point. 1:1 Play: well My play: paper. paper covers well. My point. 1:2 Play: > rps rps7 RPS-7 Choices are rock, scissors, sponge, fire, paper, air, water. Enter one of these choices as your play. Anything else ends the game. Running score shown as <your wins>:<my wins> Play: air My play: water. air evaporates water. Your point. 1:0 Play:
Haskell
<lang haskell>import System.Random (randomRIO)
data Choice
= Rock | Paper | Scissors deriving (Show, Eq)
beats :: Choice -> Choice -> Bool beats Paper Rock = True beats Scissors Paper = True beats Rock Scissors = True beats _ _ = False
genrps :: (Int, Int, Int) -> IO Choice genrps (r, p, s) = rps <$> rand
where
rps x
| x <= s = Rock
| x <= s + r = Paper
| otherwise = Scissors
rand = randomRIO (1, r + p + s) :: IO Int
getrps :: IO Choice getrps = rps <$> getLine
where rps "scissors" = Scissors rps "rock" = Rock rps "paper" = Paper rps _ = error "invalid input"
game :: (Int, Int, Int) -> IO a game (r, p, s) = do
putStrLn "rock, paper or scissors?"
h <- getrps
c <- genrps (r, p, s)
putStrLn ("Player: " ++ show h ++ " Computer: " ++ show c)
putStrLn
(if beats h c
then "player wins\n"
else if beats c h
then "player loses\n"
else "draw\n")
let rr =
if h == Rock
then r + 1
else r
pp =
if h == Paper
then p + 1
else p
ss =
if h == Scissors
then s + 1
else s
game (rr, pp, ss)
main :: IO a main = game (1, 1, 1)</lang>
Icon and Unicon
The key to this comes down to two structures and two lines of code. The player history historyP is just an ordered list of every player turn and provides the weight for the random selection. The beats list is used to rank moves and to choose the move that would beat the randomly selected move. <lang Icon>link printf
procedure main()
printf("Welcome to Rock, Paper, Scissors.\n_
Rock beats scissors, Scissors beat paper, and Paper beats rock.\n\n")
historyP := ["rock","paper","scissors"] # seed player history winP := winC := draws := 0 # totals
beats := ["rock","scissors","paper","rock"] # what beats what 1 apart
repeat {
printf("Enter your choice or rock(r), paper(p), scissors(s) or quit(q):")
turnP := case map(read()) of {
"q"|"quit": break
"r"|"rock": "rock"
"p"|"paper": "paper"
"s"|"scissors": "scissors"
default: printf(" - invalid choice.\n") & next
}
turnC := beats[(?historyP == beats[i := 2 to *beats],i-1)] # choose move
put(historyP,turnP) # record history
printf("You chose %s, computer chose %s",turnP,turnC)
(beats[p := 1 to *beats] == turnP) &
(beats[c := 1 to *beats] == turnC) & (abs(p-c) <= 1) # rank play
if p = c then
printf(" - draw (#%d)\n",draws +:= 1 )
else if p > c then
printf(" - player win(#%d)\n",winP +:= 1)
else
printf(" - computer win(#%d)\n",winC +:= 1)
}
printf("\nResults:\n %d rounds\n %d Draws\n %d Computer wins\n %d Player wins\n",
winP+winC+draws,draws,winC,winP)
end</lang>
Sample output:
Welcome to Rock, Paper, Scissors. Rock beats scissors, Scissors beat paper, and Paper beats rock. Enter your choice or rock(r), paper(p), scissors(s) or quit(q):s You chose scissors, computer chose scissors - draw (#1) Enter your choice or rock(r), paper(p), scissors(s) or quit(q):p You chose paper, computer chose paper - draw (#2) Enter your choice or rock(r), paper(p), scissors(s) or quit(q):r You chose rock, computer chose scissors - computer win(#1) Enter your choice or rock(r), paper(p), scissors(s) or quit(q):r You chose rock, computer chose rock - draw (#3) Enter your choice or rock(r), paper(p), scissors(s) or quit(q):p You chose paper, computer chose paper - draw (#4) Enter your choice or rock(r), paper(p), scissors(s) or quit(q):s You chose scissors, computer chose scissors - draw (#5) Enter your choice or rock(r), paper(p), scissors(s) or quit(q):r You chose rock, computer chose rock - draw (#6) Enter your choice or rock(r), paper(p), scissors(s) or quit(q):r You chose rock, computer chose paper - player win(#1) Enter your choice or rock(r), paper(p), scissors(s) or quit(q):q Results: 8 rounds 6 Draws 1 Computer wins 1 Player wins
IS-BASIC
<lang IS-BASIC>100 PROGRAM "Rock.bas" 110 RANDOMIZE 120 STRING CH$(1 TO 3)*8,K$*1 130 NUMERIC PLWINS(1 TO 3),SCORE(1 TO 3),PLSTAT(1 TO 3),CMSTAT(1 TO 3),PLCHOICE,CMCHOICE 140 CALL INIC 150 DO 160 CALL GUESS 170 PRINT :PRINT "Rock, paper, or scissors (1 = rock, 2 = paper, 3 = scissors, ESC = quit)" 180 DO 190 LET K$=INKEY$ 200 LOOP UNTIL K$>="1" AND K$<="3" OR K$=CHR$(27) 210 IF K$=CHR$(27) THEN EXIT DO 220 LET PLCHOICE=VAL(K$) 230 LET CMSTAT(CMCHOICE)=CMSTAT(CMCHOICE)+1:LET PLSTAT(PLCHOICE)=PLSTAT(PLCHOICE)+1 240 PRINT "You chose ";CH$(PLCHOICE);" and I chose ";CH$(CMCHOICE);"." 250 SET #102:INK 3 260 IF PLCHOICE=CMCHOICE THEN 270 PRINT "Tie!" 280 LET SCORE(3)=SCORE(3)+1 290 ELSE IF CMCHOICE=PLWINS(PLCHOICE) THEN 300 PRINT "You won!" 310 LET SCORE(1)=SCORE(1)+1 320 ELSE 330 PRINT "I won!" 340 LET SCORE(2)=SCORE(2)+1 350 END IF 360 SET #102:INK 1 370 LOOP 380 PRINT :PRINT "Some useless statistics:" 390 PRINT "You won";SCORE(1);"times, and I won";SCORE(2);"times;";SCORE(3);"ties." 400 PRINT :PRINT ,,CH$(1),CH$(2),CH$(3) 410 PRINT "You chose:",PLSTAT(1),PLSTAT(2),PLSTAT(3) 420 PRINT " I chose:",CMSTAT(1),CMSTAT(2),CMSTAT(3) 430 END 440 DEF INIC 450 LET CH$(1)="rock":LET CH$(2)="paper":LET CH$(3)="scissors" 460 LET PLWINS(1)=3:LET PLWINS(2)=1:LET PLWINS(3)=2 470 FOR I=1 TO 3 480 LET PLSTAT(I),CMSTAT(I),SCORE(I)=0 490 NEXT 500 TEXT 80 510 END DEF 520 DEF GUESS 530 LET CMCHOICE=INT(RND*(PLSTAT(1)+PLSTAT(2)+PLSTAT(3)+3)) 540 SELECT CASE CMCHOICE 550 CASE 0 TO PLSTAT(1) 560 LET CMCHOICE=2 570 CASE PLSTAT(1)+1 TO PLSTAT(1)+PLSTAT(2)+1 580 LET CMCHOICE=3 590 CASE ELSE 600 LET CMCHOICE=1 610 END SELECT 620 END DEF</lang>
J
<lang j>require'general/misc/prompt strings' NB. was 'misc strings' in older versions of J game=:3 :0
outcomes=. rps=. 0 0 0
choice=. 1+?3
while.#response=. prompt' Choose Rock, Paper or Scissors: ' do.
playerchoice=. 1+'rps' i. tolower {.deb response
if.4 = playerchoice do.
smoutput 'Unknown response.'
smoutput 'Enter an empty line to quit'
continue.
end.
smoutput ' I choose ',choice {::;:'. Rock Paper Scissors'
smoutput (wintype=. 3 | choice-playerchoice) {:: 'Draw';'I win';'You win'
outcomes=. outcomes+0 1 2 = wintype
rps=. rps+1 2 3=playerchoice
choice=. 1+3|(?0) I.~ (}:%{:)+/\ 0, rps
end.
('Draws:','My wins:',:'Your wins: '),.":,.outcomes
)</lang>
Example use (playing to give the computer implementation the advantage):
<lang j> game
Choose Rock, Paper or Scissors: rock I choose Scissors
You win
Choose Rock, Paper or Scissors: rock I choose Paper
I win
Choose Rock, Paper or Scissors: rock I choose Paper
I win
Choose Rock, Paper or Scissors: rock I choose Paper
I win
Choose Rock, Paper or Scissors: rock I choose Paper
I win
Choose Rock, Paper or Scissors:
Draws: 0 My wins: 4 Your wins: 1</lang>
Java
This could probably be made simpler, but some more complexity is necessary so that other items besides rock, paper, and scissors can be added (as school children and nerds like to do [setup for rock-paper-scissors-lizard-spock is in multi-line comments]). The method getAIChoice() borrows from the Ada example in spirit, but is more generic to additional items.
<lang java5>import java.util.Arrays;
import java.util.EnumMap;
import java.util.List;
import java.util.Map;
import java.util.Scanner;
import java.util.Random;
public class RPS { public enum Item{ ROCK, PAPER, SCISSORS, /*LIZARD, SPOCK*/; public List<Item> losesToList; public boolean losesTo(Item other) { return losesToList.contains(other); } static { SCISSORS.losesToList = Arrays.asList(ROCK/*, SPOCK*/); ROCK.losesToList = Arrays.asList(PAPER/*, SPOCK*/); PAPER.losesToList = Arrays.asList(SCISSORS/*, LIZARD*/); /* SPOCK.losesToList = Arrays.asList(PAPER, LIZARD); LIZARD.losesToList = Arrays.asList(SCISSORS, ROCK); */
}
} //EnumMap uses a simple array under the hood public final Map<Item, Integer> counts = new EnumMap<Item, Integer>(Item.class){{ for(Item item:Item.values()) put(item, 1); }};
private int totalThrows = Item.values().length;
public static void main(String[] args){ RPS rps = new RPS(); rps.run(); }
public void run() { Scanner in = new Scanner(System.in); System.out.print("Make your choice: "); while(in.hasNextLine()){ Item aiChoice = getAIChoice(); String input = in.nextLine(); Item choice; try{ choice = Item.valueOf(input.toUpperCase()); }catch (IllegalArgumentException ex){ System.out.println("Invalid choice"); continue; } counts.put(choice, counts.get(choice) + 1); totalThrows++; System.out.println("Computer chose: " + aiChoice); if(aiChoice == choice){ System.out.println("Tie!"); }else if(aiChoice.losesTo(choice)){ System.out.println("You chose...wisely. You win!"); }else{ System.out.println("You chose...poorly. You lose!"); } System.out.print("Make your choice: "); } }
private static final Random rng = new Random(); private Item getAIChoice() { int rand = rng.nextInt(totalThrows); for(Map.Entry<Item, Integer> entry:counts.entrySet()){ Item item = entry.getKey(); int count = entry.getValue(); if(rand < count){ List<Item> losesTo = item.losesToList; return losesTo.get(rng.nextInt(losesTo.size())); } rand -= count; } return null; } }</lang> Sample output:
Make your choice: rock Computer chose: PAPER You chose...poorly. You lose! Make your choice: rock Computer chose: SCISSORS You chose...wisely. You win! Make your choice: rock Computer chose: PAPER You chose...poorly. You lose! Make your choice: rock Computer chose: SCISSORS You chose...wisely. You win! Make your choice: rock Computer chose: PAPER You chose...poorly. You lose! Make your choice: rock Computer chose: ROCK Tie! Make your choice: rock Computer chose: ROCK Tie! Make your choice: rock Computer chose: PAPER You chose...poorly. You lose! Make your choice: rock Computer chose: PAPER You chose...poorly. You lose! Make your choice: rock Computer chose: PAPER You chose...poorly. You lose! Make your choice: scissors Computer chose: PAPER You chose...wisely. You win! Make your choice: scissors Computer chose: PAPER You chose...wisely. You win! ...
JavaScript
<lang javascript> const logic = {
rock: { w: 'scissor', l: 'paper'},
paper: {w:'rock', l:'scissor'},
scissor: {w:'paper', l:'rock'},
}
class Player {
constructor(name){
this.name = name;
}
setChoice(choice){
this.choice = choice;
}
challengeOther(PlayerTwo){
return logic[this.choice].w === PlayerTwo.choice;
}
}
const p1 = new Player('Chris'); const p2 = new Player('John');
p1.setChoice('rock'); p2.setChoice('scissor');
p1.challengeOther(p2); //true (Win) </lang>
Julia
<lang julia>function rps() print("Welcome to Rock, paper, scissors! Go ahead and type your pick.\n r(ock), p(aper), or s(cissors)\n Enter 'q' to quit.\n>") comp_score = 0 user_score = 0 options = ["r","p","s"] new_pick() = options[rand(1:3)] i_win(m,y) = ((m == "r" && y == "s")|(m == "s" && y == "p")|(m == "p" && y == "r")) while true input = string(readline(STDIN)[1]) input == "q" && break !ismatch(r"^[rps]",input) && begin print("Invalid guess: Please enter 'r', 'p', or 's'\n"); continue end answer = new_pick() if input == answer print("\nTie!\nScore still: \nyou $user_score\nme $comp_score\n>") continue else i_win(answer,input) ? (comp_score += 1) : (user_score += 1) print(i_win(answer,input) ? "\nSorry you lose!\n" : "\nYou win!","Score: \nyou $user_score\nme $comp_score\n>") end end end</lang>
julia> rps() Welcome to Rock, paper, scissors! Go ahead and type your pick. r(ock), p(aper), or s(cissors) Enter 'q' to quit. >r You win!Score: you 1 me 0 >p Sorry you lose! Score: you 1 me 1 >s You win!Score: you 2 me 1
Kotlin
<lang scala>// version 1.2.10
import java.util.Random
const val choices = "rpsq" val rand = Random()
var pWins = 0 // player wins var cWins = 0 // computer wins var draws = 0 // neither wins var games = 0 // games played val pFreqs = arrayOf(0, 0, 0) // player frequencies for each choice (rps)
fun printScore() = println("Wins: You $pWins, Computer $cWins, Neither $draws\n")
fun getComputerChoice(): Char {
// make a completely random choice until 3 games have been played
if (games < 3) return choices[rand.nextInt(3)]
val num = rand.nextInt(games)
return when {
num < pFreqs[0] -> 'p'
num < pFreqs[0] + pFreqs[1] -> 's'
else -> 'r'
}
}
fun main(args: Array<String>) {
println("Enter: (r)ock, (p)aper, (s)cissors or (q)uit\n")
while (true) {
printScore()
var pChoice: Char
while (true) {
print("Your choice r/p/s/q : ")
val input = readLine()!!.toLowerCase()
if (input.length == 1) {
pChoice = input[0]
if (pChoice in choices) break
}
println("Invalid choice, try again")
}
if (pChoice == 'q') {
println("OK, quitting")
return
}
val cChoice = getComputerChoice()
println("Computer's choice : $cChoice")
if (pChoice == 'r' && cChoice == 's') {
println("Rock breaks scissors - You win!")
pWins++
}
else if (pChoice == 'p' && cChoice == 'r') {
println("Paper covers rock - You win!")
pWins++
}
else if (pChoice == 's' && cChoice == 'p') {
println("Scissors cut paper - You win!")
pWins++
}
else if (pChoice == 's' && cChoice == 'r') {
println("Rock breaks scissors - Computer wins!")
cWins++
}
else if (pChoice == 'r' && cChoice == 'p') {
println("Paper covers rock - Computer wins!")
cWins++
}
else if (pChoice == 'p' && cChoice == 's') {
println("Scissors cut paper - Computer wins!")
cWins++
}
else {
println("It's a draw!")
draws++
}
pFreqs[choices.indexOf(pChoice)]++
games++
println()
}
}</lang>
Sample session:
Enter: (r)ock, (p)aper, (s)cissors or (q)uit Wins: You 0, Computer 0, Neither 0 Your choice r/p/s/q : r Computer's choice : r It's a draw! Wins: You 0, Computer 0, Neither 1 Your choice r/p/s/q : p Computer's choice : s Scissors cut paper - Computer wins! Wins: You 0, Computer 1, Neither 1 Your choice r/p/s/q : p Computer's choice : r Paper covers rock - You win! Wins: You 1, Computer 1, Neither 1 Your choice r/p/s/q : s Computer's choice : s It's a draw! Wins: You 1, Computer 1, Neither 2 Your choice r/p/s/q : p Computer's choice : p It's a draw! Wins: You 1, Computer 1, Neither 3 Your choice r/p/s/q : q OK, quitting
Lasso
Notes: This implementation uses the default session handling in Lasso, and assumes it's running on a web server. User choices are passed in via HTTP as GET query parameters. <lang Lasso>session_start('user') session_addvar('user', 'historic_choices') session_addvar('user', 'win_record') session_addvar('user', 'plays') var(historic_choices)->isNotA(::map) ? var(historic_choices = map('rock'=0, 'paper'=0, 'scissors'=0)) var(plays)->isNotA(::integer) ? var(plays = 0) var(win_record)->isNotA(::array) ? var(win_record = array)
define br => '
'
define winner(c::string,p::string) => {
if(#c == $superior->find(#p)) => {
$win_record->insert('lasso')
return 'Lasso'
else(#p == $superior->find(#c))
$win_record->insert('user')
return 'User'
else
$win_record->insert('tie')
return 'Nobody'
}
}
var(
choice = web_request->param('choice')->asString,
lookup = array('rock', 'paper', 'scissors'),
computer_choice = $lookup->get(math_random(3,1)),
superior = map('rock'='paper', 'paper'='scissors', 'scissors'='rock'),
controls = '<a href=?choice=rock>Rock</a> <a href=?choice=paper>Paper</a> <a href=?choice=scissors>Scissors</a> <a href=?choice=quit>Quit</a>
'
)
if($choice == 'quit') => {^
'See ya. <a href=?>Start over</a>'
session_end('user')
$historic_choices = map('rock'=0, 'paper'=0, 'scissors'=0)
$plays = 0
$win_record = array
else(array('rock','paper','scissors') >> $choice) $controls
if($plays != 0) => { local('possibilities') = array with i in $lookup do => { loop($historic_choices->find(#i)) => { #possibilities->insert(#i) } }
$computer_choice = $superior->find(#possibilities->get(math_random($plays,1))) }
'User chose ' + $choice + br 'Lasso chose ' + $computer_choice + br winner($computer_choice->asString, $choice) + ' wins!'
$historic_choices->find($choice) = $historic_choices->find($choice)+1 $plays += 1
else($choice->size == 0) $controls
else 'Invalid Choice.'+ br + $controls ^} if($win_record->size) => {^ br br 'Win record: '+br 'Lasso: '+($win_record->find('lasso')->size)+br 'User: '+($win_record->find('user')->size)+br 'Tie: '+($win_record->find('tie')->size)+br ^}</lang>
- Output:
Rock Paper Scissors Quit (<- as links) User chose paper Lasso chose rock User wins! Win record: Lasso: 2 User: 1 Tie: 3
Liberty BASIC
<lang lb> dim rps( 2), g$( 3)
g$( 0) ="rock": g$( 1) ="paper": g$( 2) ="scissors" global total
total =0: draw =0: pwin =0: cwin =0
rps( 0) =1: rps( 1) =1: rps( 2) =1 ' at first computer will play all three with equal probability
c =int( 3 *rnd( 1)) ' first time, computer response is random
' In the following code we set three integer %ages for the <human>'s biassed throws.
' set up the <human> player's key frequencies as %ages.
' Done like this it's easy to mimic the <human> input of q$
' It allows only integer %age frequency- not an important thing.
rockP =45 ' <<<<<<<<< Set here the <human>'s %age of 'rock' choices. for i =1 to rockP: qF$ =qF$ +"R": next i
paprP =24 ' <<<<<<<<< Set here the %age of 'paper' choices. for i =1 to paprP: qF$ =qF$ +"P": next i
scisP =100 -rockP -paprP ' <<<<<<<<< %age 'scissors' calculated to make 100% for i =1 to scisP: qF$ =qF$ +"S": next i 'print qF$
do
'do: input q$:loop until instr( "RPSrpsQq", q$) ' for actual human input... possibly biassed. <<<<<<<<<<<<< REM one or the other line... q$ =mid$( qF$, int( 100 *rnd( 1)), 1) ' simulated <human> input with controlled bias. <<<<<<<<<<<<<
if total >10000 then q$ ="Q"
g =int( ( instr( "RrPpSsQq", q$) -1) / 2) if g >2 then [endGame]
total =total +1 rps( g) =rps( g) +1 ' accumulate plays the <human> has chosen. ( & hence their (biassed?) frequencies.) 'print " You chose "; g$( g); " and I chose "; g$( c); ". "
select case g -c
case 0
draw =draw +1 ':print "It's a draw"
case 1, -2
pwin =pwin +1 ':print "You win!"
case -1, 2
cwin =cwin +1 ':print "I win!"
end select
r =int( total *rnd( 1)) ' Now select computer's choice for next confrontation.
select case ' Using the accumulating data about <human>'s frequencies so far.
case r <=rps( 0)
c =1
case r <=( rps( 0) +rps( 1))
c =2
case else
c =0
end select
scan
loop until 0
[endGame]
print print " You won "; pwin; ", and I won "; cwin; ". There were "; draw; " draws." if cwin >pwin then print " I AM THE CHAMPION!!" else print " You won this time." print print " At first I assumed you'd throw each equally often." print " This means I'd win 1 time in 3; draw 1 in 3; lose 1 in 3." print " However if I detect a bias in your throws,...." print " ....this allows me to anticipate your most likely throw & on average beat it." print print " In fact, keyboard layout & human frailty mean even if you TRY to be even & random..." print " ... you may be typing replies with large bias. In 100 tries I gave 48 'P's, 29 'R' & 23 'S'!" print print " This time I played.." print " Rock "; using( "##.##", rps( 2)* 100 /total); "% Paper "; using( "##.##", rps( 0) *100 /total); "% Scissors "; using( "##.##", rps( 1) *100 /total); "%." print print " ( PS. I have since learned your actual bias had been.." print " Rock "; using( "##.##", rockP); "% Paper "; using( "##.##", paprP ); "% Scissors "; using( "##.##", ( 100 -rockP -paprP)); "%.)" print print " The advantage I can gain gets bigger the further the 'human' entries are biassed." print " The results statistically smooth out better with large runs." print " Try 10,000,000, & have a cuppa while you wait." print print " Can you see what will happen if, say, the 'human' is set to give 'Rock' EVERY time?" print " Try different %ages by altering the marked code lines." print print " Thanks for playing!" end
</lang>
You won 3204, and I won 3669. There were 3128 draws.
I AM THE CHAMPION!!
At first I assumed you'd throw each equally often.
This means I'd win 1 time in 3; draw 1 in 3; lose 1 in 3.
However if I detect a bias in your throws,....
....this allows me to anticipate your most likely throw & on average beat it.
In fact, keyboard layout & human frailty mean even if you TRY to be even & random...
... you may be typing replies with large bias. In 100 tries I gave 48 'P's, 29 'R' & 23 'S'!
This time I played..
Rock 30.17% Paper 45.93% Scissors 23.94%.
( PS. I have since learned your actual bias had been..
Rock 45.00% Paper 24.00% Scissors 31.00%.)
The advantage I can gain gets bigger the further the 'human' entries are biassed.
The results statistically smooth out better with large runs.
Try 10,000,000, & have a cuppa while you wait.
Can you see what will happen if, say, the 'human' is set to give 'Rock' EVERY time?
Try different %ages by altering the marked code lines.
Locomotive Basic
<lang locobasic>10 mode 1:defint a-z:randomize time 20 rps$="rps" 30 msg$(1)="Rock breaks scissors" 40 msg$(2)="Paper covers rock" 50 msg$(3)="Scissors cut paper" 60 print "Rock Paper Scissors":print 70 print "Enter r, p, or s as your play." 80 print "Running score shown as <your wins>:<my wins>" 90 achoice=rnd*2.99+.5 ' get integer between 1 and 3 from real between .5 and <3.5 100 ' get key 110 pin$=inkey$ 120 if pin$="" then 110 130 pchoice=instr(rps$,pin$) 140 if pchoice=0 then print "Sorry?":goto 110 150 pcf(pchoice)=pcf(pchoice)+1 160 plays=plays+1 170 print "My play: "mid$(rps$,achoice,1) 180 sw=(achoice-pchoice+3) mod 3 190 if sw=0 then print "Tie." else if sw=1 then print msg$(achoice);". My point.":ascore=ascore+1 else print msg$(pchoice);". Your point.":pscore=pscore+1 200 print pscore":"ascore 210 rn=rnd*plays 220 if rn<pcf(1) then achoice=2 else if rn<pcf(1)+pcf(2) then achoice=3 else achoice=1 230 goto 110</lang>
Lua
<lang Lua>function cpuMove()
local totalChance = record.R + record.P + record.S if totalChance == 0 then -- First game, unweighted random local choice = math.random(1, 3) if choice == 1 then return "R" end if choice == 2 then return "P" end if choice == 3 then return "S" end end local choice = math.random(1, totalChance) -- Weighted random bit if choice <= record.R then return "P" end if choice <= record.R + record.P then return "S" end return "R"
end
function playerMove() -- Get user input for choice of 'weapon'
local choice
repeat
os.execute("cls") -- Windows specific command, change per OS
print("\nRock, Paper, Scissors")
print("=====================\n")
print("Scores -\tPlayer:", score.player)
print("\t\tCPU:", score.cpu .. "\n\t\tDraws:", score.draws)
io.write("\nChoose [R]ock [P]aper or [S]cissors: ")
choice = io.read():upper():sub(1, 1)
until choice == "R" or choice == "P" or choice == "S"
return choice
end
-- Decide who won, increment scores function checkWinner (c, p)
io.write("I chose ")
if c == "R" then print("rock...") end
if c == "P" then print("paper...") end
if c == "S" then print("scissors...") end
if c == p then
print("\nDraw!")
score.draws = score.draws + 1
elseif (c == "R" and p == "P") or
(c == "P" and p == "S") or
(c == "S" and p == "R") then
print("\nYou win!")
score.player = score.player + 1
else
print("\nYou lose!")
score.cpu = score.cpu + 1
end
end
-- Main procedure math.randomseed(os.time()) score = {player = 0, cpu = 0, draws = 0} record = {R = 0, P = 0, S = 0} local playerChoice, cpuChoice repeat
cpuChoice = cpuMove()
playerChoice = playerMove()
record[playerChoice] = record[playerChoice] + 1
checkWinner(cpuChoice, playerChoice)
io.write("\nPress ENTER to continue or enter 'Q' to quit . . . ")
until io.read():upper():sub(1, 1) == "Q"</lang> Session in which I chose nothing but rock:
Rock, Paper, Scissors
=====================
Scores - Player: 1
CPU: 25
Draws: 0
Choose [R]ock [P]aper or [S]cissors: r
I chose paper...
You lose!
Press ENTER to continue or enter 'Q' to quit . . .
Mathematica
<lang mathematica>DynamicModule[{record, play, text = "\nRock-paper-scissors\n",
choices = {"Rock", "Paper", "Scissors"}},
Evaluate[record /@ choices] = {1, 1, 1};
play[x_] :=
Module[{y = RandomChoice[record /@ choices -> RotateLeft@choices]},
record[x]++;
text = "Your Choice:" <> x <> "\nComputer's Choice:" <> y <> "\n" <>
Switch[{x, y}, Alternatives @@ Partition[choices, 2, 1, 1],
"You lost.",
Alternatives @@ Reverse /@ Partition[choices, 2, 1, 1],
"You win.", _, "Draw."]];
Column@{Dynamic[text], ButtonBar[# :> play[#] & /@ choices]}]</lang>
Mercury
<lang Mercury>:- module rps.
- - interface.
- - import_module io.
- - pred main(io::di, io::uo) is det.
- - implementation.
- - use_module random, exception.
- - import_module list, string.
- - type play
---> rock ; paper ; scissors.
- - pred beats(play, play).
- - mode beats(in, in) is semidet.
beats(rock, scissors). beats(paper, rock). beats(scissors, paper).
- - pred random(play::out, random.supply::mdi, random.supply::muo) is det.
random(Play, !RS) :-
random.random(1, 3, N, !RS),
( if N = 1 then
Play = rock
else if N = 2 then
Play = paper
else
Play = scissors
).
main(!IO) :-
seed(Seed, !IO), random.init(Seed, RS), play(RS, !IO).
- - pred play(random.supply::mdi, io::di, io::uo) is det.
play(!.RS, !IO) :-
io.write_string("Your choice? ", !IO),
io.read(Res, !IO),
(
Res = ok(Play),
random(Counter, !RS),
io.format("The computer chose %s\n", [s(string(Counter))], !IO),
( if beats(Counter, Play) then
io.write_string("Computer wins.\n", !IO)
else if beats(Play, Counter) then
io.write_string("You win!\n", !IO)
else
io.write_string("It is a draw\n", !IO)
),
play(!.RS, !IO)
;
Res = eof
;
Res = error(_, _),
exception.throw(Res)
).
- - pragma foreign_decl("C", "#include <time.h>").
- - pred seed(int::out, io::di, io::uo) is det.
- - pragma foreign_proc("C",
seed(Seed::out, _IO0::di, _IO::uo), [promise_pure, will_not_call_mercury],
"
Seed = time(NULL);
").</lang>
NS-HUBASIC
<lang NS-HUBASIC>10 COMPUTER=RND(3)+1 20 COMPUTER$="ROCK" 30 IF COMPUTER=2 THEN COMPUTER$="PAPER" 40 IF COMPUTER=3 THEN COMPUTER$="SCISSORS" 50 INPUT "ROCK, PAPER OR SCISSORS? ",HUMAN$ 60 IF HUMAN$="ROCK" THEN GOTO 100 70 IF HUMAN$="PAPER" THEN GOTO 100 80 IF HUMAN$="SCISSORS" THEN GOTO 100 90 PRINT "INVALID GUESS. TRY AGAIN.": GOTO 50 100 PRINT "YOU CHOSE "HUMAN$" AND THE COMPUTER CHOSE "COMPUTER$"." 110 IF HUMAN$=COMPUTER$ THEN PRINT "THOSE ARE THE SAME CHOICES";", SO YOU TIED." 120 IF HUMAN$="ROCK" AND COMPUTER=2 THEN PRINT "PAPER COVERS ROCK, SO YOU LOSE." 130 IF HUMAN$="ROCK" AND COMPUTER=3 THEN PRINT "ROCK BLUNTS SCISSORS";", SO YOU WIN." 140 IF HUMAN$="PAPER" AND COMPUTER=1 THEN PRINT "PAPER COVERS ROCK, SO YOU WIN." 150 IF HUMAN$="PAPER" AND COMPUTER=3 THEN PRINT "SCISSORS CUT PAPER";", SO YOU LOSE." 160 IF HUMAN$="SCISSORS" AND COMPUTER=1 THEN PRINT "ROCK BLUNTS SCISSORS";", SO YOU LOSE." 170 IF HUMAN$="SCISSORS" AND COMPUTER=2 THEN PRINT "SCISSORS CUT PAPER, SO YOU WIN."10 COMPUTER=RND(3)+1</lang>
OCaml
<lang OCaml> let pf = Printf.printf ;;
let looses a b = match a, b with
`R, `P -> true | `P, `S -> true | `S, `R -> true | _, _ -> false ;;
let rec get_move () =
pf "[R]ock, [P]aper, [S]cisors [Q]uit? " ;
match String.uppercase (read_line ()) with
"P" -> `P
| "S" -> `S
| "R" -> `R
| "Q" -> exit 0
| _ -> get_move () ;;
let str_of_move = function
`P -> "paper"
| `R -> "rock"
| `S -> "scisors" ;;
let comp_move r p s =
let tot = r +. p +. s in
let n = Random.float 1.0 in
if n < r /. tot then
`R
else
if n < (r +. p) /. tot then
`P
else
`S ;;
let rec make_moves r p s =
let cm = comp_move r p s in (* Computer move is based on game history. *)
let hm = get_move () in (* Human move is requested. *)
pf "Me: %s. You: %s. " (str_of_move cm) (str_of_move hm);
let outcome =
if looses hm cm then
"I win. You loose.\n"
else if cm = hm then
"We draw.\n"
else
"You win. I loose.\n"
in pf "%s" outcome;
match hm with (* Play on with adapted strategy. *)
`S -> make_moves (r +. 1.) p s
| `R -> make_moves r (p +. 1.) s
| `P -> make_moves r p (s +. 1.) ;;
(* Main loop. *) make_moves 1. 1. 1. ;;
</lang>
PARI/GP
<lang parigp>contest(rounds)={
my(v=[1,1,1],wins,losses); \\ Laplace rule
for(i=1,rounds,
my(computer,player,t);
t=random(v[1]+v[2]+v[3]);
if(t<v[1], computer = "R",
if(t<v[1]+v[2], computer = "P", computer = "S")
);
print("Rock, paper, or scissors?");
t = Str(input());
if(#t,
player=Vec(t)[1];
if(player <> "R" && player <> "P", player = "S")
,
player = "S"
);
if (player == "R", v[2]++);
if (player == "P", v[3]++);
if (player == "S", v[1]++);
print1(player" vs. "computer": ");
if (computer <> player,
if((computer == "R" && player = "P") || (computer == "P" && player = "S") || (computer == "S" && player == "R"),
print("You win");
losses++
,
print("I win");
wins++
)
,
print("Tie");
)
);
[wins,losses]
}; contest(10)</lang>
Perl
The program supports "--quiet" option, which makes it suppress all in-game output (useful for batch testing). At the end of a game it displays detailed statistics. <lang perl> use 5.012; use warnings; use utf8; use open qw(:encoding(utf-8) :std); use Getopt::Long;
package Game {
use List::Util qw(shuffle first);
my $turns = 0;
my %human_choice = ( rock => 0, paper => 0, scissors => 0, );
my %comp_choice = ( rock => 0, paper => 0, scissors => 0, );
my %what_beats =
( rock => 'paper', paper => 'scissors', scissors => 'rock', );
my $comp_wins = 0;
my $human_wins = 0;
my $draws = 0;
sub save_human_choice {
my $ch = lc pop;
if ( exists $human_choice{ $ch } ) {
++$human_choice{ $ch };
}
else {
die __PACKAGE__ . ":: wrong choice: '$ch'";
}
}
sub get_comp_choice {
my @keys = shuffle keys %human_choice;
my $ch;
my ( $prob, $rand ) = ( 0, rand );
$ch = ( first { $rand <= ( $prob += ( $human_choice{ $_ } / $turns ) ) } @keys )
if $turns > 0;
$ch //= $keys[0];
$ch = $what_beats{ $ch };
++$comp_choice{ $ch };
return $ch;
}
sub make_turn {
my ( $comp_ch, $human_ch ) = ( pop(), pop() );
++$turns;
if ( $what_beats{ $human_ch } eq $comp_ch ) {
++$comp_wins;
return 'I win!';
}
elsif ( $what_beats{ $comp_ch } eq $human_ch ) {
++$human_wins;
return 'You win!';
}
else {
++$draws;
return 'Draw!';
}
}
sub get_final_report {
my $report =
"You chose:\n"
. " rock = $human_choice{rock} times,\n"
. " paper = $human_choice{paper} times,\n"
. " scissors = $human_choice{scissors} times,\n"
. "I chose:\n"
. " rock = $comp_choice{rock} times,\n"
. " paper = $comp_choice{paper} times,\n"
. " scissors = $comp_choice{scissors} times,\n"
. "Turns: $turns\n"
. "I won: $comp_wins, you won: $human_wins, draws: $draws\n";
return $report;
}
}
sub main {
GetOptions( 'quiet' => \my $quiet );
greet() if !$quiet;
while (1) {
print_next_line() if !$quiet;
my $input = get_input();
last unless $input;
if ( $input eq 'error' ) {
print "I don't understand!\n" if !$quiet;
redo;
}
my $comp_choice = Game::get_comp_choice();
Game::save_human_choice($input);
my $result = Game::make_turn( $input, $comp_choice );
describe_turn_result( $input, $comp_choice, $result )
if !$quiet;
}
print Game::get_final_report();
}
sub greet {
print "Welcome to the Rock-Paper-Scissors game!\n"
. "Choose 'rock', 'paper' or 'scissors'\n"
. "Enter empty line or 'quit' to quit\n";
}
sub print_next_line {
print 'Your choice: ';
}
sub get_input {
my $input = <>;
print "\n" and return if !$input; # EOF
chomp $input;
return if !$input or $input =~ m/\A \s* q/xi;
return
( $input =~ m/\A \s* r/xi ) ? 'rock'
: ( $input =~ m/\A \s* p/xi ) ? 'paper'
: ( $input =~ m/\A \s* s/xi ) ? 'scissors'
: 'error';
}
sub describe_turn_result {
my ( $human_ch, $comp_ch, $result ) = @_; print "You chose \u$human_ch, I chose \u$comp_ch. $result\n";
}
main(); </lang> Example input can be generated as follows: <lang bash> perl -e '@c=qw(r p s); for(1..10000){ print $c[ rand() < 0.75 ? 0 : int rand(2) + 1 ], "\n" }' | perl rps.pl --quiet </lang> Output:
You chose: rock = 7542 times, paper = 1204 times, scissors = 1254 times, I chose: rock = 1275 times, paper = 7460 times, scissors = 1265 times, Turns: 10000 I won: 5920, you won: 2012, draws: 2068
Example of an interactive session:
Welcome to the Rock-Paper-Scissors game! Choose 'rock', 'paper' or 'scissors' Enter empty line or 'quit' to quit Your choice: s You chose Scissors, I chose Paper. You win! Your choice: s You chose Scissors, I chose Rock. I win! Your choice: s You chose Scissors, I chose Rock. I win! Your choice: s You chose Scissors, I chose Rock. I win! Your choice: s You chose Scissors, I chose Rock. I win! Your choice: p You chose Paper, I chose Rock. You win! Your choice: s You chose Scissors, I chose Rock. I win! Your choice: q You chose: rock = 0 times, paper = 1 times, scissors = 6 times, I chose: rock = 6 times, paper = 1 times, scissors = 0 times, Turns: 7 I won: 5, you won: 2, draws: 0
Perl 6
This is slightly more complicated than it could be; it is a general case framework with input filtering. It weights the computers choices based on your previous choices. Type in at least the first two characters of your choice, or just hit enter to quit. Customize it by supplying your own %vs options/outcomes.
Here is standard Rock-Paper-Scissors.
<lang perl6>my %vs = (
options => [<Rock Paper Scissors>],
ro => {
ro => [ 2, ],
pa => [ 1, 'Paper covers Rock: ' ],
sc => [ 0, 'Rock smashes Scissors: ' ]
},
pa => {
ro => [ 0, 'Paper covers Rock: ' ],
pa => [ 2, ],
sc => [ 1, 'Scissors cut Paper: ' ]
},
sc => {
ro => [ 1, 'Rock smashes Scissors: '],
pa => [ 0, 'Scissors cut Paper: ' ],
sc => [ 2, ]
}
);
my %choices = %vs<options>.map({; $_.substr(0,2).lc => $_ }); my $keys = %choices.keys.join('|'); my $prompt = %vs<options>.map({$_.subst(/(\w\w)/, -> $/ {"[$0]"})}).join(' ')~"? "; my %weight = %choices.keys »=>» 1;
my @stats = 0,0,0; my $round;
while my $player = (prompt "Round {++$round}: " ~ $prompt).lc {
$player.=substr(0,2);
say 'Invalid choice, try again.' and $round-- and next
unless $player.chars == 2 and $player ~~ /<$keys>/;
my $computer = (flat %weight.keys.map( { $_ xx %weight{$_} } )).pick;
%weight{$_.key}++ for %vs{$player}.grep( { $_.value[0] == 1 } );
my $result = %vs{$player}{$computer}[0];
@stats[$result]++;
say "You chose %choices{$player}, Computer chose %choices{$computer}.";
print %vs{$player}{$computer}[1];
print ( 'You win!', 'You Lose!','Tie.' )[$result];
say " - (W:{@stats[0]} L:{@stats[1]} T:{@stats[2]})\n",
};</lang>Example output:
Round 1: [Ro]ck [Pa]per [Sc]issors? ro You chose Rock, Computer chose Paper. Paper covers Rock: You Lose! - (W:0 L:1 T:0) Round 2: [Ro]ck [Pa]per [Sc]issors? pa You chose Paper, Computer chose Scissors. Scissors cut Paper: You Lose! - (W:0 L:2 T:0) Round 3: [Ro]ck [Pa]per [Sc]issors? pa You chose Paper, Computer chose Scissors. Scissors cut Paper: You Lose! - (W:0 L:3 T:0) Round 4: [Ro]ck [Pa]per [Sc]issors? ro You chose Rock, Computer chose Rock. Tie. - (W:0 L:3 T:1) Round 5: [Ro]ck [Pa]per [Sc]issors? sc You chose Scissors, Computer chose Scissors. Tie. - (W:0 L:3 T:2) ...
Here is example output from the same code only with a different %vs data structure implementing Rock-Paper-Scissors-Lizard-Spock.
<lang perl6>my %vs = (
options => [<Rock Paper Scissors Lizard Spock>],
ro => {
ro => [ 2, ],
pa => [ 1, 'Paper covers Rock: ' ],
sc => [ 0, 'Rock smashes Scissors: ' ],
li => [ 0, 'Rock crushes Lizard: ' ],
sp => [ 1, 'Spock vaporizes Rock: ' ]
},
pa => {
ro => [ 0, 'Paper covers Rock: ' ],
pa => [ 2, ],
sc => [ 1, 'Scissors cut Paper: ' ],
li => [ 1, 'Lizard eats Paper: ' ],
sp => [ 0, 'Paper disproves Spock: ' ]
},
sc => {
ro => [ 1, 'Rock smashes Scissors: ' ],
pa => [ 0, 'Scissors cut Paper: ' ],
sc => [ 2, ],
li => [ 0, 'Scissors decapitate Lizard: '],
sp => [ 1, 'Spock smashes Scissors: ' ]
},
li => {
ro => [ 1, 'Rock crushes Lizard: ' ],
pa => [ 0, 'Lizard eats Paper: ' ],
sc => [ 1, 'Scissors decapitate Lizard: '],
li => [ 2, ],
sp => [ 0, 'Lizard poisons Spock: ' ]
},
sp => {
ro => [ 0, 'Spock vaporizes Rock: ' ],
pa => [ 1, 'Paper disproves Spock: ' ],
sc => [ 0, 'Spock smashes Scissors: ' ],
li => [ 1, 'Lizard poisons Spock: ' ],
sp => [ 2, ]
}
);</lang>
Round 1: [Ro]ck [Pa]per [Sc]issors [Li]zard [Sp]ock? li You chose Lizard, Computer chose Scissors. Scissors decapitate Lizard: You Lose! - (W:0 L:1 T:0) Round 2: [Ro]ck [Pa]per [Sc]issors [Li]zard [Sp]ock? sp You chose Spock, Computer chose Paper. Paper disproves Spock: You Lose! - (W:0 L:2 T:0) Round 3: [Ro]ck [Pa]per [Sc]issors [Li]zard [Sp]ock? ro You chose Rock, Computer chose Lizard. Rock crushes Lizard: You Win! - (W:1 L:2 T:0) Round 4: [Ro]ck [Pa]per [Sc]issors [Li]zard [Sp]ock? ro You chose Rock, Computer chose Scissors. Rock smashes Scissors: You win! - (W:2 L:2 T:0) Round 5: [Ro]ck [Pa]per [Sc]issors [Li]zard [Sp]ock? li You chose Lizard, Computer chose Paper. Lizard eats Paper: You win! - (W:3 L:2 T:0) ...
Phix
<lang Phix>--standard game constant rule3 = {"rock blunts scissors",
"paper wraps rock",
"scissors cut paper"}
--extended version constant rule5 = {"rock blunts scissors",
"rock crushes lizard",
"paper wraps rock",
"paper disproves spock",
"scissors cut paper",
"scissors decapitate lizard",
"lizard eats paper",
"lizard poisons spock",
"spock smashes scissors",
"spock vaporizes rock"}
constant rules = iff(rand(2)=1?rule3:rule5)
sequence what = {} sequence beats = {} string wkeys = "" string question = "What is your move " integer choices, hsum sequence history, cplays, pplays
object x, verb, y
for i=1 to length(rules) do
{x} = split(rules[i])
if not find(x,what) then
what = append(what,x)
if find(x[1],wkeys) then
wkeys = append(wkeys,x[$])
question &= x[1..-2]&"("&x[$]&"), "
else
wkeys = append(wkeys,x[1])
question &= "("&x[1]&")"&x[2..$]&", "
end if
end if
end for
choices = length(wkeys)
history = repeat(1,choices)
hsum = 3
cplays = repeat(0,choices)
pplays = repeat(0,choices)
beats = repeat(repeat(0,choices),choices)
question[-2] = '?'
for i=1 to length(rules) do
{x,verb,y} = split(rules[i])
beats[find(x,what)][find(y,what)] = verb
end for
integer cmove, pmove, draws = 0, pwins = 0, cwins = 0
while 1 do
cmove = rand(hsum)
for i=1 to choices do
cmove -= history[i]
if cmove<=0 then
-- predicted user choice of i, find whatever beats it
for j=1 to choices do
if string(beats[j][i]) then
cmove = j
exit
end if
end for
exit
end if
end for
puts(1,question)
while 1 do
pmove = lower(wait_key())
if pmove='q' then exit end if
pmove = find(pmove,wkeys)
if pmove!=0 then exit end if
end while
if pmove='q' then exit end if
printf(1,"you: %s, me: %s, ",{what[pmove],what[cmove]})
cplays[cmove] += 1
pplays[pmove] += 1
if cmove=pmove then
printf(1,"a draw.\n")
draws += 1
else
if string(beats[cmove][pmove]) then
printf(1,"%s %s %s. I win.\n",{what[cmove],beats[cmove][pmove],what[pmove]})
cwins += 1
elsif string(beats[pmove][cmove]) then
printf(1,"%s %s %s. You win.\n",{what[pmove],beats[pmove][cmove],what[cmove]})
pwins += 1
else
?9/0 -- sanity check
end if
end if
history[pmove] += 1
hsum += 1
end while
printf(1,"\n\nYour wins:%d, My wins:%d, Draws:%d\n",{pwins,cwins,draws})
printf(1,"\n\nYour wins:%d, My wins:%d, Draws:%d\n",{pwins,cwins,draws})
printf(1," ") for i=1 to choices do printf(1,"%9s",what[i]) end for
printf(1,"\nyou: ") for i=1 to choices do printf(1,"%9d",pplays[i]) end for
printf(1,"\n me: ") for i=1 to choices do printf(1,"%9d",cplays[i]) end for</lang>
- Output:
What is your move (r)ock, (p)aper, (s)cissors? you: rock, me: scissors, rock blunts scissors. You win.
What is your move (r)ock, (p)aper, (s)cissors? you: rock, me: rock, a draw.
What is your move (r)ock, (p)aper, (s)cissors? you: rock, me: paper, paper wraps rock. I win.
What is your move (r)ock, (p)aper, (s)cissors? you: rock, me: rock, a draw.
What is your move (r)ock, (p)aper, (s)cissors? you: rock, me: paper, paper wraps rock. I win.
What is your move (r)ock, (p)aper, (s)cissors? you: rock, me: paper, paper wraps rock. I win.
What is your move (r)ock, (p)aper, (s)cissors? you: rock, me: paper, paper wraps rock. I win.
What is your move (r)ock, (p)aper, (s)cissors? you: rock, me: paper, paper wraps rock. I win.
What is your move (r)ock, (p)aper, (s)cissors? you: rock, me: paper, paper wraps rock. I win.
What is your move (r)ock, (p)aper, (s)cissors? you: rock, me: paper, paper wraps rock. I win.
What is your move (r)ock, (p)aper, (s)cissors?
Your wins:1, My wins:7, Draws:2
rock paper scissors
you: 10 0 0
me: 2 7 1
PHP
Use the url bar to play
e.g: www.example.com/rockpaper.php?moves=paper
www.example.com/rockpaper.php?moves=rock
<lang PHP>
<?php
echo "
" . "Choose: ROCK - PAPER - SCISSORS" . "
"; echo "
";
echo "";
$player = strtoupper( $_GET["moves"] );
$wins = [
'ROCK' => 'SCISSORS',
'PAPER' => 'ROCK',
'SCISSORS' => 'PAPER'
];
$a_i = array_rand($wins);
echo "
";
echo "Player chooses " . "" . $player . "";
echo "
";
echo "
" . "A.I chooses " . "" . $a_i . "";
$results = "";
if ($player == $a_i){
$results = "Draw";
} else if($wins[$a_i] == $player ){
$results = "A.I wins";
} else {
$results = "Player wins";
}
echo "
" . $results;
?>
</lang>
PicoLisp
<lang PicoLisp>(use (C Mine Your)
(let (Rock 0 Paper 0 Scissors 0)
(loop
(setq Mine
(let N (if (gt0 (+ Rock Paper Scissors)) (rand 1 @) 0)
(seek
'((L) (le0 (dec 'N (caar L))))
'(Rock Paper Scissors .) ) ) )
(prin "Enter R, P or S to play, or Q to quit: ")
(loop
(and (= "Q" (prinl (setq C (uppc (key))))) (bye))
(T (setq Your (find '((S) (pre? C S)) '(Rock Paper Scissors))))
(prinl "Bad input - try again") )
(prinl
"I say " (cadr Mine) ", You say " Your ": "
(cond
((== Your (cadr Mine)) "Draw")
((== Your (car Mine)) "I win")
(T "You win") ) )
(inc Your) ) ) )</lang>
PL/I
<lang PL/I>
rock: procedure options (main); /* 30 October 2013 */
declare move character (1), cm fixed binary;
put ('The Rock-Paper-Scissors game');
put skip list ("please type 'r' for rock, 'p' for paper, 's' for scissors.");
put skip list ("Anything else finishes:");
do forever;
get edit (move) (a(1));
move = lowercase(move);
if index('rpsq', move) = 0 then iterate;
if move = 'q' then stop;
cm = random()*3; /* computer moves: 0 = rock, 1 = paper, 2 = scissors */
select (cm);
when (0) select (move);
when ('r') put list ('rock and rock: A draw');
when ('p') put list ('paper beats rock: You win');
when ('s') put list ('rock breaks scissors: I win');
end;
when (1) select (move);
when ('r') put list ('paper beats rock: I win');
when ('p') put list ('paper and paper: A draw');
when ('s') put list ('scissors cut paper: You win');
end;
when (2) select (move);
when ('r') put list ('rock breaks scissors: You win');
when ('p') put list ('scissors cuts paper: I win');
when ('s') put list ('Scissors and Scissors: A draw');
end;
end;
end;
end rock;
</lang>
Prolog
<lang prolog>play :-
findall(P,beats(P,_),Prev),
play(Prev).
play(Prev) :-
write('your choice? '),
read(P),
random_member(C, Prev),
format('The computer chose ~p~n', C),
result(C,P,Prev,Next),
!,
play(Next).
result(C,P,R,[C|R]) :-
beats(C,P),
format('Computer wins.~n').
result(C,P,R,[B|R]) :-
beats(P,C),
beats(B,P),
format('You win!~n').
result(C,C,R,[B|R]) :-
beats(B,C),
format('It is a draw~n').
beats(paper, rock).
beats(rock, scissors).
beats(scissors, paper).</lang>
PureBasic
<lang purebasic>Enumeration
;choices are in listed according to their cycle, weaker followed by stronger
#rock
#paper
#scissors
#numChoices ;this comes after all possible choices
EndEnumeration
- give names to each of the choices
Dim choices.s(#numChoices - 1)
choices(#rock) = "rock"
choices(#paper) = "paper"
choices(#scissors) = "scissors"
Define gameCount
Dim playerChoiceHistory(#numChoices - 1)
Procedure weightedRandomChoice()
Shared gameCount, playerChoiceHistory()
Protected x = Random(gameCount - 1), t, c
For i = 0 To #numChoices - 1
t + playerChoiceHistory(i)
If t >= x
c = i
Break
EndIf
Next
ProcedureReturn (c + 1) % #numChoices
EndProcedure
If OpenConsole()
PrintN("Welcome to the game of rock-paper-scissors")
PrintN("Each player guesses one of these three, and reveals it at the same time.")
PrintN("Rock blunts scissors, which cut paper, which wraps stone.")
PrintN("If both players choose the same, it is a draw!")
PrintN("When you've had enough, choose Q.")
Define computerChoice, playerChoice, response.s
Define playerWins, computerWins, draw, quit
computerChoice = Random(#numChoices - 1)
Repeat
Print(#CRLF$ + "What is your move (press R, P, or S)?")
Repeat
response = LCase(Input())
Until FindString("rpsq", response) > 0
If response = "q":
quit = 1
Else
gameCount + 1
playerChoice = FindString("rps", response) - 1
result = (playerChoice - computerChoice + #numChoices) % #numChoices
Print("You chose " + choices(playerChoice) + " and I chose " + choices(computerChoice))
Select result
Case 0
PrintN(". It's a draw.")
draw + 1
Case 1
PrintN(". You win!")
playerWins + 1
Case 2
PrintN(". I win!")
computerWins + 1
EndSelect
playerChoiceHistory(playerChoice) + 1
computerChoice = weightedRandomChoice()
EndIf
Until quit
Print(#CRLF$ + "You chose: ")
For i = 0 To #numChoices - 1
Print(choices(i) + " " + StrF(playerChoiceHistory(i) * 100 / gameCount, 1) + "%; ")
Next
PrintN("")
PrintN("You won " + Str(playerWins) + ", and I won " + Str(computerWins) + ". There were " + Str(draw) + " draws.")
PrintN("Thanks for playing!")
Print(#CRLF$ + #CRLF$ + "Press ENTER to exit"): Input()
CloseConsole()
EndIf</lang>
Sample output:
Welcome to the game of rock-paper-scissors
Each player guesses one of these three, and reveals it at the same time.
Rock blunts scissors, which cut paper, which wraps stone.
If both players choose the same, it is a draw!
When you've had enough, choose Q.
What is your move (press R, P, or S)?r
You chose rock and I chose paper. I win!
What is your move (press R, P, or S)?r
You chose rock and I chose paper. I win!
What is your move (press R, P, or S)?r
You chose rock and I chose paper. I win!
What is your move (press R, P, or S)?r
You chose rock and I chose paper. I win!
What is your move (press R, P, or S)?r
You chose rock and I chose paper. I win!
What is your move (press R, P, or S)?s
You chose scissors and I chose paper. You win!
What is your move (press R, P, or S)?r
You chose rock and I chose paper. I win!
What is your move (press R, P, or S)?s
You chose scissors and I chose paper. You win!
What is your move (press R, P, or S)?s
You chose scissors and I chose paper. You win!
What is your move (press R, P, or S)?s
You chose scissors and I chose paper. You win!
What is your move (press R, P, or S)?s
You chose scissors and I chose rock. I win!
What is your move (press R, P, or S)?q
You chose: rock 54.5%; paper 0.0%; scissors 45.5%;
You won 4, and I won 7. There were 0 draws.
Thanks for playing!
Python
A light version with limited support for additional rules. New weapons can be introduced, but each can only be beaten by one other weapon.
The rules dictionary is of the form 'this': beaten by 'that', etc as opposed to 'this': beats 'that'.
<lang python>from random import choice
rules = {'rock': 'paper', 'scissors': 'rock', 'paper': 'scissors'}
previous = ['rock', 'paper', 'scissors']
while True:
human = input('\nchoose your weapon: ')
computer = rules[choice(previous)] # choose the weapon which beats a randomly chosen weapon from "previous"
if human in ('quit', 'exit'): break
elif human in rules:
previous.append(human)
print('the computer played', computer, end='; ')
if rules[computer] == human: # if what beats the computer's choice is the human's choice...
print('yay you win!')
elif rules[human] == computer: # if what beats the human's choice is the computer's choice...
print('the computer beat you... :(')
else: print("it's a tie!")
else: print("that's not a valid choice")</lang>
Output, where player always chooses Rock:
choose your weapon: rock
the computer played rock; it's a tie!
choose your weapon: rock
the computer played scissors; yay you win!
choose your weapon: rock
the computer played paper; the computer beat you... :(
choose your weapon: rock
the computer played paper; the computer beat you... :(
choose your weapon: rock
the computer played paper; the computer beat you... :(
This is another code. Output is as same as the above output.
<lang python>from random import randint
hands = ['rock', 'scissors', 'paper']; judge = ['its a tie!', 'the computer beat you... :(', 'yay you win!']
while True:
try:
YOU = hands.index(input('Choose your weapon: ')) # YOU = hands.index(raw_input('Choose your weapon: ')) If you use Python2.7
except ValueError:
break
NPC = randint(0, 2)
print('The computer played ' + hands[NPC] + '; ' + judge[YOU-NPC])</lang>
Rascal
<lang rascal>import Prelude;
rel[str, str] whatbeats = {<"Rock", "Scissors">, <"Scissors", "Paper">, <"Paper", "Rock">};
list[str] ComputerChoices = ["Rock", "Paper", "Scissors"];
str CheckWinner(a, b){
if(b == getOneFrom(whatbeats[a]))
return a;
elseif(a == getOneFrom(whatbeats[b]))
return b;
else return "Nobody";
}
public str RPS(human){
computer = getOneFrom(ComputerChoices);
x = if(human == "Rock") "Paper"; elseif(human == "Paper") "Scissors"; else "Rock";
ComputerChoices += x;
return "Computer played <computer>. <CheckWinner(human, computer)> wins!";
}</lang>
Sample output:
<lang rascal>rascal>RPS("Rock")
str: "Computer played Rock. Nobody wins!"
rascal>RPS("Rock")
str: "Computer played Rock. Nobody wins!"
rascal>RPS("Rock")
str: "Computer played Scissors. Rock wins!"
rascal>RPS("Rock")
str: "Computer played Paper. Paper wins!"
rascal>RPS("Rock")
str: "Computer played Paper. Paper wins!"
rascal>RPS("Rock")
str: "Computer played Paper. Paper wins!"
rascal>RPS("Rock")
str: "Computer played Paper. Paper wins!"
rascal>RPS("Rock")
str: "Computer played Rock. Nobody wins!"
rascal>RPS("Rock")
str: "Computer played Paper. Paper wins!"
rascal>RPS("Rock")
str: "Computer played Paper. Paper wins!"</lang>
Racket
<lang racket>
- lang racket
(require math)
(define history (make-hash '((paper . 1) (scissors . 1) (rock . 1))))
(define total 3)
(define (update-history! human-choice)
(set! total (+ total 1))
(hash-update! history human-choice add1 0))
(define (pick-one)
(sample
(discrete-dist '(paper scissors rock)
(map (λ (x) (hash-ref history x))
'(scissors paper rock)))))
(define (find-winner computer human)
(define order '(scissors paper rock scissors))
(cond
[(eq? computer human) 'none]
[(eq? (second (member computer order)) human) 'computer]
[ 'human]))
(define (game-loop)
(define computer-choice (pick-one))
(define human-choice (read))
(define winner (find-winner computer-choice human-choice))
(update-history! human-choice)
(displayln (~a "Computer picked " computer-choice ", "
"human picked " human-choice ", "
winner " wins."))
(game-loop))
(game-loop)
</lang>
REXX
traditional, 3 choices
This REXX program version:
- allows the human player to abbreviate their choice
- issues appropriate error messages for an incorrect (or no) choice(s)
- allows the human player to QUIT at any time
- keeps track of the human player's responses (to hopefully make future computer winning choices)
- uses better "English"/grammer, i.e.: rock breaks scissors, and paper covers rock.
<lang rexx>/*REXX program plays rock─paper─scissors with a human; tracks what human tends to use. */
!= '────────'; err=! '***error***'; @.=0 /*some constants for this program. */
prompt= ! 'Please enter one of: Rock Paper Scissors (or Quit)'
$.p='paper' ; $.s='scissors'; $.r='rock' /*list of the choices in this program. */
t.p=$.r ; t.s=$.p ; t.r=$.s /*thingys that beats stuff. */
w.p=$.s ; w.s=$.r ; w.r=$.p /*stuff " " thingys. */
b.p='covers'; b.s='cuts' ; b.r='breaks' /*verbs: how the choice wins. */
do forever; say; say prompt; say /*prompt the CBLF; then get a response.*/
c=word($.p $.s $.r, random(1, 3) ) /*choose the computer's first pick. */
m=max(@.r, @.p, @.s); c=w.r /*prepare to examine the choice history*/
if @.p==m then c=w.p /*emulate JC's: The Amazing Karnac. */
if @.s==m then c=w.s /* " " " " " */
c1=left(c, 1) /*C1 is used for faster comparing. */
parse pull u; a=strip(u) /*get the CBLF's choice/pick (answer). */
upper a c1 ; a1=left(a, 1) /*uppercase choices, get 1st character.*/
ok=0 /*indicate answer isn't OK (so far). */
select /*process/verify the CBLF's choice. */
when words(u)==0 then say err 'nothing entered'
when words(u)>1 then say err 'too many choices: ' u
when abbrev('QUIT', a) then do; say ! 'quitting.'; exit; end
when abbrev('ROCK', a) |,
abbrev('PAPER', a) |,
abbrev('SCISSORS',a) then ok=1 /*Yes? This is a valid answer by CBLF.*/
otherwise say err 'you entered a bad choice: ' u
end /*select*/
if \ok then iterate /*answer ¬OK? Then get another choice.*/
@.a1=@.a1+1 /*keep a history of the CBLF's choices.*/
say ! 'computer chose: ' c
if a1== c1 then do; say ! 'draw.'; iterate; end
if $.a1==t.c1 then say ! 'the computer wins. ' ! $.c1 b.c1 $.a1
else say ! 'you win! ' ! $.a1 b.a1 $.c1
end /*forever*/ /*stick a fork in it, we're all done. */</lang>
- output with various responses from the user (output shown is a screen scraping):
──────── Please enter one of: Rock Paper Scissors (or Quit)
s ◄■■■■■■■■■■■■■■■ human input.
──────── computer chose: rock
──────── the computer wins. ──────── rock breaks scissors
──────── Please enter one of: Rock Paper Scissors (or Quit)
s ◄■■■■■■■■■■■■■■■ human input.
──────── computer chose: rock
──────── the computer wins. ──────── rock breaks scissors
──────── Please enter one of: Rock Paper Scissors (or Quit)
s ◄■■■■■■■■■■■■■■■ human input.
──────── computer chose: rock
──────── the computer wins. ──────── rock breaks scissors
──────── Please enter one of: Rock Paper Scissors (or Quit)
s ◄■■■■■■■■■■■■■■■ human input.
──────── computer chose: rock
──────── the computer wins. ──────── rock breaks scissors
──────── Please enter one of: Rock Paper Scissors (or Quit)
s ◄■■■■■■■■■■■■■■■ human input.
──────── computer chose: rock
──────── the computer wins. ──────── rock breaks scissors
──────── Please enter one of: Rock Paper Scissors (or Quit)
p ◄■■■■■■■■■■■■■■■ human input.
──────── computer chose: rock
──────── you win! ──────── paper covers rock
──────── Please enter one of: Rock Paper Scissors (or Quit)
q ◄■■■■■■■■■■■■■■■ human input.
──────── quitting.
extended, 5 choices
This REXX version supports more choices: rock paper scissors lizard Spock
<lang rexx>/*REXX pgm plays rock─paper─scissors─lizard─Spock with human; tracks human usage trend. */
!= '────────'; err=! '***error***'; @.=0 /*some constants for this REXX program.*/
prompt=! 'Please enter one of: Rock Paper SCissors Lizard SPock (Vulcan) (or Quit)'
$.p='paper' ; $.s='scissors' ; $.r='rock' ; $.L='lizard' ; $.v='Spock' /*names of the thingys*/
t.p= $.r $.v ; t.s= $.p $.L ; t.r= $.s $.L ; t.L= $.p $.v ; t.v= $.r $.s /*thingys beats stuff.*/
w.p= $.L $.s ; w.s= $.v $.r ; w.r= $.v $.p ; w.L= $.r $.s ; w.v= $.L $.p /*stuff beats thingys.*/
b.p='covers disproves'; b.s="cuts decapitates"; b.r='breaks crushes'; b.L="eats poisons"; b.v='vaporizes smashes' /*how the choice wins.*/
whom.1=! 'the computer wins. ' !; whom.2=! "you win! " !; win=words(t.p)
do forever; say; say prompt; say /*prompt CBLF; then get a response. */
c=word($.p $.s $.r $.L $.v, random(1, 5) ) /*the computer's first choice/pick. */
m=max(@.r,@.p,@.s,@.L,@.v) /*used in examining CBLF's history. */
if @.p==m then c=word(w.p, random(1, 2) ) /*emulate JC's The Amazing Karnac. */
if @.s==m then c=word(w.s, random(1, 2) ) /* " " " " " */
if @.r==m then c=word(w.r, random(1, 2) ) /* " " " " " */
if @.L==m then c=word(w.L, random(1, 2) ) /* " " " " " */
if @.v==m then c=word(w.v, random(1, 2) ) /* " " " " " */
c1=left(c, 1) /*C1 is used for faster comparing. */
parse pull u; a=strip(u) /*obtain the CBLF's choice/pick. */
upper a c1 ; a1=left(a, 1) /*uppercase the choices, get 1st char. */
ok=0 /*indicate answer isn't OK (so far). */
select /* [↓] process the CBLF's choice/pick.*/
when words(u)==0 then say err 'nothing entered.'
when words(u)>1 then say err 'too many choices: ' u
when abbrev('QUIT', a) then do; say ! 'quitting.'; exit; end
when abbrev('LIZARD', a) |,
abbrev('ROCK', a) |,
abbrev('PAPER', a) |,
abbrev('VULCAN', a) |,
abbrev('SPOCK', a,2) |,
abbrev('SCISSORS',a,2) then ok=1 /*it's a valid choice for the human. */
otherwise say err 'you entered a bad choice: ' u
end /*select*/
if \ok then iterate /*answer ¬OK? Then get another choice.*/
@.a1= @.a1 + 1 /*keep a history of the CBLF's choices.*/
say ! 'computer chose: ' c
if a1==c1 then say ! 'draw.' /*Oh rats! The contest ended up a draw*/
else do who=1 for 2 /*either the computer or the CBLF won. */
if who==2 then parse value a1 c1 with c1 a1
do j=1 for win /*see who won. */
if $.a1 \== word(t.c1, j) then iterate /*not this 'un. */
say whom.who $.c1 word(b.c1, j) $.a1 /*notify winner.*/
leave /*leave J loop.*/
end /*j*/
end /*who*/
end /*forever*/ /*stick a fork in it, we're all done. */</lang>
- output is similar to the 1st REXX version.
Ring
<lang ring>
- Project : Rock-paper-scissors
see "
welcome to the game of rock-paper-scissors.
each player guesses one of these three, and reveals it at the same time.
rock blunts scissors, which cut paper, which wraps stone.
if both players choose the same, it is a draw!
when you've had enough, choose q.
"
g = ["rock","paper","scissors"]
total=0 draw=0
pwin=0 cwin=0
see "what is your move (press r, p, or s)?"
while true
c=random(2)+1
give q
gs = floor((substr("rpsq",lower(q))))
if gs>3 or gs<1
summarise()
exit
ok
total = total + 1
see"you chose " + g[gs] + " and i chose " + g[c] + nl
temp = gs-c
if temp = 0
see ". it's a draw"
draw = draw + 1
ok
if temp = 1 or temp = -2
see ". you win!"
pwin = pwin + 1
ok
if temp = (-1) or temp = 2
see ". i win!"
cwin = cwin + 1
ok
end
</lang>
Output:
welcome to the game of rock-paper-scissors.
each player guesses one of these three, and reveals it at the same time.
rock blunts scissors, which cut paper, which wraps stone.
if both players choose the same, it is a draw!
when you've had enough, choose q.
what is your move (press r, p, or s)?
r
you chose rock and i chose rock
. it's a draw
p
you chose paper and i chose paper
. it's a draw
s
you chose scissors and i chose rock
. i win!
R
you chose rock and i chose paper
. i win!
P
you chose paper and i chose paper
. it's a draw
S
you chose scissors and i chose paper
. you win!
q
you won 1, and i won 2. there were 3 draws
thanks for playing!
Ruby
<lang ruby>class RockPaperScissorsGame
CHOICES = %w[rock paper scissors quit]
BEATS = {
'rock' => 'paper',
'paper' => 'scissors',
'scissors' => 'rock',
}
def initialize()
@plays = {
'rock' => 1,
'paper' => 1,
'scissors' => 1,
}
@score = [0, 0, 0] # [0]:Human wins, [1]:Computer wins, [2]:draw
play
end
def humanPlay
loop do
print "\nYour choice: #{CHOICES}? "
answer = STDIN.gets.strip.downcase
next if answer.empty?
idx = CHOICES.find_index {|choice| choice.match(/^#{answer}/)}
return CHOICES[idx] if idx
puts "invalid answer, try again"
end
end
def computerPlay
total = @plays.values.reduce(:+)
r = rand(total) + 1
sum = 0
CHOICES.each do |choice|
sum += @plays[choice]
return BEATS[choice] if r <= sum
end
end
def play
loop do
h = humanPlay
break if h == "quit"
c = computerPlay
print "H: #{h}, C: #{c} => "
# only update the human player's history after the computer has chosen
@plays[h] += 1
if h == c
puts "draw"
@score[2] += 1
elsif h == BEATS[c]
puts "Human wins"
@score[0] += 1
else
puts "Computer wins"
@score[1] += 1
end
puts "score: human=%d, computer=%d, draw=%d" % [*@score]
end
@plays.each_key{|k| @plays[k] -= 1}
puts "\nhumans chose #{@plays}"
end
end
RockPaperScissorsGame.new</lang>
sample game where human always chooses rock:
Your choice: ["rock", "paper", "scissors", "quit"]? r
H: rock, C: rock => draw
score: human=0, computer=0, draw=1
Your choice: ["rock", "paper", "scissors", "quit"]? r
H: rock, C: scissors => Human wins
score: human=1, computer=0, draw=1
Your choice: ["rock", "paper", "scissors", "quit"]? r
H: rock, C: paper => Computer wins
score: human=1, computer=1, draw=1
Your choice: ["rock", "paper", "scissors", "quit"]? r
H: rock, C: paper => Computer wins
score: human=1, computer=2, draw=1
Your choice: ["rock", "paper", "scissors", "quit"]? r
H: rock, C: paper => Computer wins
score: human=1, computer=3, draw=1
Your choice: ["rock", "paper", "scissors", "quit"]? r
H: rock, C: paper => Computer wins
score: human=1, computer=4, draw=1
Your choice: ["rock", "paper", "scissors", "quit"]? r
H: rock, C: paper => Computer wins
score: human=1, computer=5, draw=1
Your choice: ["rock", "paper", "scissors", "quit"]? r
H: rock, C: paper => Computer wins
score: human=1, computer=6, draw=1
Your choice: ["rock", "paper", "scissors", "quit"]? r
H: rock, C: rock => draw
score: human=1, computer=6, draw=2
Your choice: ["rock", "paper", "scissors", "quit"]? r
H: rock, C: paper => Computer wins
score: human=1, computer=7, draw=2
Your choice: ["rock", "paper", "scissors", "quit"]? q
humans chose {"rock"=>10, "paper"=>0, "scissors"=>0}
Run BASIC
<lang runbasic>pri$ = "RSPR"
rps$ = "Rock,Paper,Sissors"
[loop]
button #r, "Rock", [r]
button #p, "Paper", [p]
button #s, "Scissors",[s]
button #q, "Quit", [q]
wait
[r] y = 1 :goto [me]
[p] y = 2 :goto [me]
[s] y = 3
[me]
cls
y$ = word$(rps$,y,",")
m = int((rnd(0) * 2) + 1)
m$ = word$(rps$,m,",")
print chr$(10);"You Chose:";y$;" I chose:";m$
yp = instr(pri$,left$(y$,1))
mp = instr(pri$,left$(m$,1))
if yp = 1 and mp = 3 then mp = 0
if mp = 1 and yp = 3 then yp = 0
if yp < mp then print "You win"
if yp = mp then print "Tie"
if yp > mp then print "I win"
goto [loop]
wait
[q] cls
print "Good Bye! I enjoyed the game"
end
</lang>
Rust
<lang Rust>extern crate rand;
- [macro_use]
extern crate rand_derive;
use std::io;
use rand::Rng;
use Choice::*;
- [derive(PartialEq, Clone, Copy, Rand, Debug)]
enum Choice {
Rock,
Paper,
Scissors,
}
fn beats(c1: Choice, c2: Choice) -> bool {
(c1 == Rock && c2 == Scissors) || (c1 == Scissors && c2 == Paper) || (c1 == Paper && c2 == Rock)
}
fn ai_move<R: Rng>(rng: &mut R, v: [usize; 3]) -> Choice {
// weighted random choice, a dynamic version of `rand::distributions::WeightedChoice`
let rand = rng.gen_range(0, v[0] + v[1] + v[2]);
if rand < v[0] {
Paper
} else if rand < v[0] + v[1] {
Scissors
} else {
Rock
}
}
fn main() {
let mut rng = rand::thread_rng();
println!("Rock, paper, scissors!");
let mut ai_choice: Choice = rng.gen();
let mut ucf = [0, 0, 0]; // user choice frequency
let mut score = [0, 0];
loop {
println!("Please input your move: 'r', 'p' or 's'. Type 'q' to quit");
let mut input = String::new();
io::stdin()
.read_line(&mut input)
.expect("failed to read line");
let u_choice = match input.to_lowercase().trim() {
s if s.starts_with('r') => {
ucf[0] += 1;
Rock
}
s if s.starts_with('p') => {
ucf[1] += 1;
Paper
}
s if s.starts_with('s') => {
ucf[2] += 1;
Scissors
}
s if s.starts_with('q') => break,
_ => {
println!("Please enter a correct choice!");
continue;
}
};
println!("You chose {:?}, I chose {:?}.", u_choice, ai_choice);
if beats(u_choice, ai_choice) {
score[0] += 1;
println!("You win!");
} else if u_choice == ai_choice {
println!("It's a tie!");
} else {
score[1] += 1;
println!("I win!");
}
println!("-Score: You {}, Me {}", score[0], score[1]);
// only after the 1st iteration the AI knows the stats and can make
// its weighted random move
ai_choice = ai_move(&mut rng, ucf);
}
println!("Thank you for the game!");
}</lang>
Scala
You can invoke this game with an arbitrary number of weapons:
<lang Scala>object RockPaperScissors extends App {
import scala.collection.mutable.LinkedHashMap
def play(beats: LinkedHashMap[Symbol,Set[Symbol]], played: scala.collection.Map[Symbol,Int]) {
val h = readLine(s"""Your move (${beats.keys mkString ", "}): """) match {
case null => println; return
case "" => return
case s => Symbol(s)
}
beats get h match {
case Some(losers) =>
def weighted(todo: Iterator[(Symbol,Int)], rand: Int, accum: Int = 0): Symbol = todo.next match {
case (s, i) if rand <= (accum + i) => s
case (_, i) => weighted(todo, rand, accum + i)
}
val c = weighted(played.toIterator, 1 + scala.util.Random.nextInt(played.values.sum)) match {
// choose an opponent that would beat the player's anticipated move
case h => beats.find{case (s, l) => l contains h}.getOrElse(beats.head)._1
}
print(s" My move: $c\n ")
c match {
case c if losers contains c => println("You won")
case c if beats(c) contains h => println("You lost")
case _ => println("We drew") // or underspecified
}
case x => println(" Unknown weapon, try again.")
}
play(beats, played get h match {
case None => played
case Some(count) => played.updated(h, count + 1)
})
}
def play(beats: LinkedHashMap[Symbol,Set[Symbol]]): Unit =
play(beats, beats.mapValues(_ => 1)) // init with uniform probabilities
play(LinkedHashMap(
'rock -> Set('lizard, 'scissors),
'paper -> Set('rock, 'spock),
'scissors -> Set('paper, 'lizard),
'lizard -> Set('spock, 'paper),
'spock -> Set('scissors, 'rock)
))
}</lang>
- Output:
Your move ('rock, 'paper, 'scissors, 'lizard, 'spock): paper
My move: 'paper
We drew
Your move ('rock, 'paper, 'scissors, 'lizard, 'spock): scissors
My move: 'paper
You won
Your move ('rock, 'paper, 'scissors, 'lizard, 'spock): rock
My move: 'scissors
You won
Your move ('rock, 'paper, 'scissors, 'lizard, 'spock): rock
My move: 'rock
We drew
Your move ('rock, 'paper, 'scissors, 'lizard, 'spock): rock
My move: 'paper
You lost
Your move ('rock, 'paper, 'scissors, 'lizard, 'spock): rock
My move: 'rock
We drew
Your move ('rock, 'paper, 'scissors, 'lizard, 'spock): rock
My move: 'paper
You lost
Your move ('rock, 'paper, 'scissors, 'lizard, 'spock): rock
My move: 'paper
You lost
Here's another code: (I refactored the above code, it is more functional, more testable )
<lang Scala>object RockPaperScissors extends App {
def beats = Map(
'rock -> Set('lizard, 'scissors),
'paper -> Set('rock, 'spock),
'scissors -> Set('paper, 'lizard),
'lizard -> Set('spock, 'paper),
'spock -> Set('scissors, 'rock)
)
// init with uniform probabilities
def initPlayed = beats.mapValues(_ => 1)
def input = Symbol(readLine(s"""Your move (${beats.keys mkString ", "}): """))
def random(max: Int) = scala.util.Random.nextInt(max)
def display(text: String) = print(text)
def weighted(todo: Iterator[(Symbol,Int)], rand: Int, accum: Int = 0): Symbol = todo.next match {
case (s, i) if rand <= (accum + i) => s
case (_, i) => weighted(todo, rand, accum + i)
}
def calcMyMove(random: Int => Int, played: Map[Symbol,Int]) = {
weighted(played.toIterator, 1 + random(played.values.sum)) match {
// choose an opponent that would beat the player's anticipated move
case h => beats.find{case (s, l) => l contains h}.getOrElse(beats.head)._1
}
}
case class Result(text: String, won: Int, lost: Int, drew: Int) {
override def toString = s"$text. Won: $won, Lost: $lost, Drew: $drew"
}
def getResult(userWeapon: Symbol, myMove: Symbol, result: Result) = {
if (beats(userWeapon) contains myMove)
result.copy(text = "You won", won = result.won + 1)
else if (beats(myMove) contains userWeapon)
result.copy(text = "You lost", lost = result.lost + 1)
else result.copy(text = "We drew", drew = result.drew + 1)
}
def play(input: => Symbol, display: String => Unit, random: Int => Int)
(played: Map[Symbol,Int], result: Result): Result = {
val userWeapon = input
if (userWeapon != Symbol("")) {
val newResult = if (beats contains userWeapon) {
val myMove = calcMyMove(random, played)
display(s" My move: $myMove\n ")
getResult(userWeapon, myMove, result)
} else {
result.copy(text = " Unknown weapon, try again")
}
display(newResult + "\n")
play(input, display, random)(played get userWeapon match {
case None => played
case Some(count) => played.updated(userWeapon, count + 1)
}, newResult)
} else result
}
override def main(args: Array[String]): Unit =
play(input, display, random)(initPlayed, Result("Start", 0, 0, 0))
}</lang>
- Output:
Your move ('spock, 'rock, 'lizard, 'paper, 'scissors): rock
My move: 'rock
We drew. Won: 0, Lost: 0, Drew: 1
Your move ('spock, 'rock, 'lizard, 'paper, 'scissors): spock
My move: 'spock
We drew. Won: 0, Lost: 0, Drew: 2
Your move ('spock, 'rock, 'lizard, 'paper, 'scissors): lizard
My move: 'spock
You won. Won: 1, Lost: 0, Drew: 2
Your move ('spock, 'rock, 'lizard, 'paper, 'scissors): scissors
My move: 'spock
You lost. Won: 1, Lost: 1, Drew: 2
Your move ('spock, 'rock, 'lizard, 'paper, 'scissors): scissors
My move: 'spock
You lost. Won: 1, Lost: 2, Drew: 2
Your move ('spock, 'rock, 'lizard, 'paper, 'scissors): spock
My move: 'rock
You won. Won: 2, Lost: 2, Drew: 2
Seed7
The program reads the possible commands (1, 2, 3, q) as single keypresses from the
KEYBOARD with
getc.
It is also possible to quit the program with q.
<lang seed7>$ include "seed7_05.s7i";
$ include "keybd.s7i";
const array string: rockPaperScissors is [] ("Rock", "Paper", "Scissors");
const proc: main is func
local
var char: command is ' ';
var integer: user is 0;
var integer: comp is 0;
begin
writeln("Hello, Welcome to rock-paper-scissors");
repeat
write("Please type in 1 for Rock, 2 for Paper, 3 for Scissors, q to quit ");
flush(OUT);
repeat
command := lower(getc(KEYBOARD));
until command in {'1', '2', '3', 'q'};
writeln(command);
if command <> 'q' then
user := integer parse str(command);
comp := rand(1, 3);
writeln("You Played: " <& rockPaperScissors[user]);
writeln("Computer Played: " <& rockPaperScissors[comp]);
if comp = user then
writeln("You Tied");
elsif succ(comp) = user or user + 2 = comp then
writeln("Yay, You Won!");
else
writeln("Sorry, You Lost!");
end if;
end if;
until command = 'q';
writeln("Goodbye! Thanks for playing!");
end func;</lang>
Sample run:
Hello, Welcome to rock-paper-scissors
Please type in 1 for Rock, 2 for Paper, 3 for Scissors, q to quit 1
You Played: Rock
Computer Played: Scissors
Yay, You Won!
Please type in 1 for Rock, 2 for Paper, 3 for Scissors, q to quit 2
You Played: Paper
Computer Played: Scissors
Sorry, You Lost!
Please type in 1 for Rock, 2 for Paper, 3 for Scissors, q to quit 3
You Played: Scissors
Computer Played: Paper
Yay, You Won!
Please type in 1 for Rock, 2 for Paper, 3 for Scissors, q to quit q
Goodbye! Thanks for playing!
Sidef
<lang ruby>const rps = %w(r p s)
const msg = [
"Rock breaks scissors",
"Paper covers rock",
"Scissors cut paper",
]
say <<"EOT"
\n>> Rock Paper Scissors <<\n
- Enter 'r', 'p', or 's' as your play.
- Enter 'q' to exit the game.
- Running score shown as <your wins>:<my wins>
EOT
var plays = 0
var aScore = 0
var pScore = 0
var pcf = [0,0,0] # pcf = player choice frequency
var aChoice = pick(0..2) # ai choice for first play is completely random
loop {
var pi = Sys.scanln("Play: ")
pi == 'q' && break
var pChoice = rps.index(pi)
if (pChoice == -1) {
STDERR.print("Invalid input!\n")
next
}
++pcf[pChoice]
++plays
# show result of play
">> My play: %-8s".printf(rps[aChoice])
given ((aChoice - pChoice + 3) % 3) {
when (0) { say "Tie." }
when (1) { "%-*s %s".printlnf(30, msg[aChoice], 'My point'); aScore++ }
when (2) { "%-*s %s".printlnf(30, msg[pChoice], 'Your point'); pScore++ }
}
# show score
"%-6s".printf("%d:%d" % (pScore, aScore))
# compute ai choice for next play
given (plays.rand.int) { |rn|
case (rn < pcf[0]) { aChoice = 1 }
case (pcf[0]+pcf[1] > rn) { aChoice = 2 }
default { aChoice = 0 }
}
}</lang>
Sample run:
>> Rock Paper Scissors <<
** Enter 'r', 'p', or 's' as your play.
** Enter 'q' to exit the game.
** Running score shown as <your wins>:<my wins>
Play: r
>> My play: s Rock breaks scissors Your point
1:0 Play: p
>> My play: p Tie.
1:0 Play: r
>> My play: s Rock breaks scissors Your point
2:0 Play: s
>> My play: p Scissors cut paper Your point
3:0 Play: r
>> My play: p Paper covers rock My point
3:1 Play: p
>> My play: r Paper covers rock Your point
4:1 Play: q
SuperCollider
// play it in the REPL, evaluating line by line
a = RockPaperScissors.new;
a.next(Scissors);
a.next(Scissors);
a.next(Scissors);
a.next(Paper);
An implementation using classes
Rock {
*play { |other|
^other.rock + this + "against" + other
}
*rock {
^"tie"
}
*paper {
^"loses"
}
*scissors {
^"wins"
}
*losesAgainst {
^Paper
}
}
Paper {
*play { |other|
^other.paper + this + "against" + other
}
*paper {
^"tie"
}
*scissors {
^"loses"
}
*rock {
^"wins"
}
*losesAgainst {
^Scissors
}
}
Scissors {
*play { |other|
^other.scissors + this + "against" + other
}
*scissors {
^"tie"
}
*rock {
^"loses"
}
*paper {
^"wins"
}
*losesAgainst {
^Rock
}
}
RockPaperScissors {
var opponentMoves;
*new {
^super.new.init
}
init {
opponentMoves = Bag.new;
}
findBestMatch {
var typicalMove = opponentMoves.wchoose;
if(typicalMove.isNil) { ^[Rock, Paper, Scissors].choose };
^typicalMove.losesAgainst
}
next { |otherMove|
var myMove = this.findBestMatch;
opponentMoves.add(otherMove);
^play(otherMove, myMove)
}
}
Swift
<lang Swift>enum Choice: CaseIterable {
case rock
case paper
case scissors
case lizard
case spock
}
extension Choice {
var weaknesses: Set<Choice> {
switch self {
case .rock:
return [.paper, .spock]
case .paper:
return [.scissors, .lizard]
case .scissors:
return [.rock, .spock]
case .lizard:
return [.rock, .scissors]
case .spock:
return [.paper, .lizard]
}
}
}
struct Game {
private(set) var history: [(Choice, Choice)] = []
private(set) var p1Score: Int = 0
private(set) var p2Score: Int = 0
mutating func play(_ p1Choice: Choice, against p2Choice: Choice) {
history.append((p1Choice, p2Choice))
if p2Choice.weaknesses.contains(p1Choice) {
p1Score += 1
} else if p1Choice.weaknesses.contains(p2Choice) {
p2Score += 1
}
}
}
func aiChoice(for game: Game) -> Choice {
if let weightedWeekness = game.history.flatMap({ $0.0.weaknesses }).randomElement() {
return weightedWeekness
} else {
// If history is empty, return random Choice
return Choice.allCases.randomElement()!
}
}
var game = Game()
print("Type your choice to play a round, or 'q' to quit")
loop: while true {
let choice: Choice
switch readLine().map({ $0.lowercased() }) {
case "r", "rock":
choice = .rock
case "p", "paper":
choice = .paper
case "scissors":
choice = .scissors
case "l", "lizard":
choice = .lizard
case "spock":
choice = .spock
case "q", "quit", "exit":
break loop
case "s":
print("Do you mean Spock, or scissors?")
continue
default:
print("Unknown choice. Type 'q' to quit")
continue
}
let p2Choice = aiChoice(for: game)
print("You played \(choice) against \(p2Choice)")
game.play(choice, against: p2Choice)
print("Current score: \(game.p1Score) : \(game.p2Score)")
}</lang>
Sample run:
Type your choice to play a round, or 'q' to quit
r
You played rock against paper
Current score: 0 : 1
Paper
You played paper against paper
Current score: 0 : 1
spock
You played spock against lizard
Current score: 0 : 2
lizard
You played lizard against paper
Current score: 1 : 2
q
Tcl
<lang tcl>package require Tcl 8.5
- Choices are represented by integers, which are indices into this list:
- Rock, Paper, Scissors
- Normally, idiomatic Tcl code uses names for these sorts of things, but it
- turns out that using integers simplifies the move-comparison logic.
- How to ask for a move from the human player
proc getHumanMove {} {
while 1 {
puts -nonewline "Your move? \[R\]ock, \[P\]aper, \[S\]cissors: "
flush stdout
gets stdin line
if {[eof stdin]} {
puts "\nBye!"
exit
}
set len [string length $line]
foreach play {0 1 2} name {"rock" "paper" "scissors"} {
# Do a prefix comparison
if {$len && [string equal -nocase -length $len $line $name]} {
return $play
}
}
puts "Sorry, I don't understand that. Try again please."
}
}
- How to ask for a move from the machine player
proc getMachineMove {} {
global states
set choice [expr {int(rand() * [::tcl::mathop::+ {*}$states 3])}]
foreach play {1 2 0} count $states {
if {[incr sum [expr {$count+1}]] > $choice} {
puts "I play \"[lindex {Rock Paper Scissors} $play]\""
return $play
}
}
}
- Initialize some state variables
set states {0 0 0}
set humanWins 0
set machineWins 0
- The main game loop
while 1 {
# Get the moves for this round
set machineMove [getMachineMove]
set humanMove [getHumanMove]
# Report on what happened
if {$humanMove == $machineMove} {
puts "A draw!"
} elseif {($humanMove+1)%3 == $machineMove} {
puts "I win!"
incr machineWins
} else {
puts "You win!"
incr humanWins
}
puts "Cumulative scores: $humanWins to you, $machineWins to me"
# Update the state of how the human has played in the past
lset states $humanMove [expr {[lindex $states $humanMove] + 1}]
}</lang>
Sample run:
Your move? [R]ock, [P]aper, [S]cissors: rock
I play "Scissors"
You win!
Cumulative scores: 1 to you, 0 to me
Your move? [R]ock, [P]aper, [S]cissors: r
I play "Paper"
I win!
Cumulative scores: 1 to you, 1 to me
Your move? [R]ock, [P]aper, [S]cissors: s
I play "Paper"
You win!
Cumulative scores: 2 to you, 1 to me
Your move? [R]ock, [P]aper, [S]cissors: sciss
I play "Paper"
You win!
Cumulative scores: 3 to you, 1 to me
Your move? [R]ock, [P]aper, [S]cissors: p
I play "Paper"
A draw!
Cumulative scores: 3 to you, 1 to me
Your move? [R]ock, [P]aper, [S]cissors: zaphod beeblebrox
Sorry, I don't understand that. Try again please.
Your move? [R]ock, [P]aper, [S]cissors: r
I play "Scissors"
You win!
Cumulative scores: 4 to you, 1 to me
Your move? [R]ock, [P]aper, [S]cissors: ^D
Bye!
TorqueScript
Rock Paper Scissors in TorqueScript:
<lang TorqueScript>
while(isobject(RockPaperScissors))
RockPaperScissors.delete();
new scriptObject(RockPaperScissors);
function RockPaperScissors::startGame(%this)
{
%this.idle = true;
echo("Starting rock paper scissors, please type choose(\"choice\"); to proceed!");
}
function RockPaperScissors::endGame(%this)
{
%this.idle = true;
}
function RockPaperScissors::main(%this)
{
%this.idle = 0;
if(getRandom(1,2) == 1)
{
%result = %this.getChoiceByUserFrequency();
}
else
{
%c[0] = "rock";
%c[1] = "paper";
%c[2] = "scissors";
%result = %c[getRandom(0,2)];
}
%userChoice = %this.current;
%winner = thisVSthat(%userChoice,%result);
if(%winner == 0)
{
echo("You both chose "@%userChoice@", tie!");
}
else
if(%winner == 1)
{
echo("You chose "@%userChoice@" computer chose "@%result@", you win!");
}
else
if(%winner == 2)
{
echo("You chose "@%userChoice@" computer chose "@%result@", you lose!");
}
%this.idle = true;
}
function RockPaperScissors::getChoiceByUserFrequency(%this)
{
%weakness["rock"] = "paper";
%weakness["paper"] = "Scissors";
%weakness["scissors"] = "rock";
%a[0] = %this.choice["rock"];
%a[1] = %this.choice["paper"];
%a[2] = %this.choice["Scissors"];
%b[0] = "rock";
%b[1] = "paper";
%b[2] = "scissors";
for(%i=0;%i<3;%i++)
{
%curr = %a[%i];
if(%temp $= "")
{
%temp = %curr;
%tempi = %i;
}
else
if(%curr > %temp)
{
%temp = %curr;
%tempi = %i;
}
}
return %weakness[%b[%tempi]];
}
function choose(%this)
{
%rps = rockPaperScissors;
if(!%rps.idle)
{
return 0;
}
else
if(%this !$= "rock" && %this !$= "paper" && %this !$= "scissors")
{
return 0;
}
%rps.choice[%this]++;
%rps.current = %this;
%rps.main();
return %this;
}
function thisVSthat(%this,%that)
{
if(%this !$= "rock" && %this !$= "paper" && %this !$= "scissors")
{
return 0;
}
else
if(%that !$= "rock" && %that !$= "paper" && %that !$= "scissors")
{
return 0;
}
%weakness["rock"] = "paper";
%weakness["paper"] = "Scissors";
%weakness["scissors"] = "rock";
if(%weakness[%this] $= %that)
{
%result = 2;
}
else
if(%weakness[%that] $= %this)
{
%result = 1;
}
else
%result = 0;
return %result;
}
</lang>
To begin do:
<lang TorqueScript>
RockPaperScissors.startGame();
</lang>
Choose and play!
<lang TorqueScript>
choose("Rock");
</lang>
=> You chose rock computer chose paper, you lose!
TI-83 BASIC
<lang ti83b>PROGRAM:RPS
- {0,0,0}→L1
- {0,0,0}→L2
- Lbl ST
- Disp "R/P/S"
- Disp "1/2/3"
- Lbl EC
- Input A
- If A>3 or A<1
- Then
- Goto NO
- End
- randInt(1,3+L1(1)+L1(2)+L1(3)→C
- If C≤1+L1(1)
- Then
- 2→B
- Goto NS
- End
- If C>2+L1(2)
- Then
- 1→B
- Else
- 3→B
- End
- Lbl NS
- L1(A)+1→L1(A)
- If A=B
- Then
- Disp "TIE GAME"
- L2(3)+1→L2(3)
- Goto TG
- End
- If (A=1 and B=2) or (A=2 and B=3) or (A=3 and B=1)
- Then
- Disp "I WIN"
- L2(1)+1→L2(1)
- Else
- Disp "YOU WIN"
- L2(2)+1→L2(2)
- End
- Lbl TG
- Disp "PLAY AGAIN?"
- Input Str1
- If Str1="YES"
- Then
- ClrHome
- Goto ST
- Else
- Goto EN
- End
- Lbl NO
- ClrHome
- Pause "PICK 1,2, or 3"
- ClrHome
- Goto EC
- Lbl EN
- ClrHome
- Disp "I WON:"
- Disp L2(1)
- Disp "YOU WON:"
- Disp L2(2)
- Disp "WE TIED:"
- Disp L2(3)
- Disp "BYE"
</lang>
uBasic/4tH
This implementation uses a 6-bits binary scheme, where the lower three bits represent the choice of the user and the higher three bits the choice of the computer:
<lang> 20 LET P=0: LET Q=0: LET Z=0
30 INPUT "Rock, paper, or scissors (1 = rock, 2 = paper, 3 = scissors)? ", A
40 IF A>3 THEN GOTO 400
50 IF A=3 THEN LET A=4
60 IF A<1 THEN GOTO 400
70 C=RND(3) : LET D=4: FOR B=1 TO C+1 : LET D = D+D : NEXT : GOTO (A+D)*10
90 Z=Z+1 : PRINT "We both chose 'rock'. It's a draw." : GOTO 30
100 P=P+1 : PRINT "You chose 'paper', I chose 'rock'. You win.." : GOTO 30
120 Q=Q+1 : PRINT "You chose 'scissors', I chose 'rock'. I win!" : GOTO 30
170 Q=Q+1 : PRINT "You chose 'rock', I chose 'paper'. I win!" : GOTO 30
180 Z=Z+1 : PRINT "We both chose 'paper'. It's a draw." : GOTO 30
200 P=P+1 : PRINT "You chose 'scissors', I chose 'paper'. You win.." : GOTO 30
330 P=P+1 : PRINT "You chose 'rock', I chose 'scissors'. You win.." : GOTO 30
340 Q=Q+1 : PRINT "You chose 'paper', I chose 'scissors'. I win!" : GOTO 30
360 Z=Z+1 : PRINT "We both chose 'scissors'. It's a draw." : GOTO 30
400 PRINT "There were ";Z;" draws. I lost ";P;" times, you lost ";Q;" times." : END</lang>
A sample game:
Rock, paper, or scissors (1 = rock, 2 = paper, 3 = scissors)? 1
You chose 'rock', I chose 'paper'. I win!
Rock, paper, or scissors (1 = rock, 2 = paper, 3 = scissors)? 2
You chose 'paper', I chose 'scissors'. I win!
Rock, paper, or scissors (1 = rock, 2 = paper, 3 = scissors)? 3
You chose 'scissors', I chose 'paper'. You win..
Rock, paper, or scissors (1 = rock, 2 = paper, 3 = scissors)? 1
You chose 'rock', I chose 'paper'. I win!
Rock, paper, or scissors (1 = rock, 2 = paper, 3 = scissors)? 2
We both chose 'paper'. It's a draw.
Rock, paper, or scissors (1 = rock, 2 = paper, 3 = scissors)? 3
You chose 'scissors', I chose 'rock'. I win!
Rock, paper, or scissors (1 = rock, 2 = paper, 3 = scissors)? 4
There were 1 draws. I lost 1 times, you lost 4 times.
UNIX Shell
<lang bash>#!/bin/bash
choices=(rock paper scissors)
- comparison function, works like Perl
- winner x y = 2 if y beats x, 1 if x beats 1, 0 if it's a tie
winner() {
local left="$1" right="$2"
echo $(( (3 + left - right) % 3 ))
}
human_counts=(1 1 1)
human_count=3
computer_counts=(0 0 0)
games=0 human=0 computer=0
PS3="What do you throw? "
while true; do
select choice in rock paper scissors quit; do
if [ -z "$choice" ]; then choice="$REPLY"; fi
if [ "$choice" = "quit" ]; then
break 2
fi
for (( h=0; h<${#choices[@]}; ++h )); do
if [ "${choices[h]}" = "$choice" ]; then
break
fi
done
if (( h < 3 )); then
break
fi
echo "Unrecognized choice. Try again!"
done
let n=RANDOM%human_count
for (( c=0; c<${#human_counts[@]}; ++c )); do
let n-=${human_counts[c]}
if (( n < 0 )); then
break
fi
done
let computer_counts[c]+=1
echo
echo "You chose ${choices[h]^^}"
echo "I chose ${choices[c]^^}"
w="$(winner "$c" "$h")"
case "$w" in
2) echo "YOU WIN!"; let human+=1;;
0) echo "TIE!";;
1) echo "I WIN!"; let computer+=1;;
*) echo "winner returned weird result '$w'";;
esac
echo
let games+=1
(( human_counts[(h+1)%3]+=1, human_count+=1 ))
done
echo
echo "We played $games games. You won $human, and I won $computer."
for (( i=0; i<3; ++i )); do
echo "You picked ${choices[i]} $(( human_counts[ (i+1)%3 ] - 1 )) times."
echo "I picked ${choices[i]} $(( computer_counts[i] )) times."
done</lang>
Wee Basic
Due to how the code works, any key has to be entered for the computer's choice to be generated.
<lang Wee Basic>let entered=0
let keycode=0
let rcounter=1
print 1 "Enter R for rock, P for paper, or S for scissors. (not case sensitive)"
while entered=0
input human$
if human=$="r"
let human$="rock"
let entered=1
elseif human=$="R"
let human$="rock"
let entered=1
elseif human=$="p"
let human$="paper"
let entered=1
elseif human=$="P"
let human$="paper"
let entered=1
elseif human=$="s"
let human$="scissors"
let entered=1
elseif human=$="S"
let human$="scissors"
let entered=1
elseif entered=0
print 1 "That choice is invalid."
endif
wend
print 1 "Press any key so the computer can make its choice."
while keycode=0
let rcounter=rcounter+1
let keycode=key()
if rcounter=4
let rcounter=1
endif
wend
if rcounter=1
let cpu$="rock"
elseif rcounter=2
let cpu$="paper"
elseif rcounter=3
let cpu$="scissors"
endif
print 1 "You chose"+human$+"."
print 1 "The computer chose"+cpu$+"."
if human$=cpu$
print 1 "You tied."
endif
if human$="rock"
if cpu$="paper"
print 1 "Paper covers rock, so you lose."
endif
if cpu$="scissors"
print 1 "Rock blunts scissors, so you win."
endif
endif
if human$="paper"
if cpu$="rock"
print 1 "Paper covers rock, so you win."
endif
if cpu$="scissors"
print 1 "Scissors cut paper, so you lose."
endif
endif
if human$="scissors"
if cpu$="rock"
print 1 "Rock blunts scissors, so you lose."
endif
if cpu$="paper"
print 1 "Scissors cut paper, so you win."
endif
endif
end</lang>
Yabasic
<lang Yabasic>REM Yabasic 2.763 version
WINNER = 1 : ACTION = 2 : LOSSER = 3
dim word$(10, 3)
for n = 0 to 9
read word$(n, WINNER), word$(n, ACTION), word$(n, LOSSER)
next n
repeat
clear screen
computerChoice$ = word$(ran(10), WINNER)
print "'Rock, Paper, Scissors, Lizard, Spock!' rules are:\n"
for n = 0 to 9
SimonSay(n)
next n
print "\nType your choice letter:"
print "(R)ock, (P)aper, (S)cissors, (L)izard, Spoc(K), (Q)uit\n"
k$ = upper$(inkey$)
if k$ = "Q" break
switch k$
case "R": humanChoice$ = "Rock" : break
case "P": humanChoice$ = "Paper" : break
case "S": humanChoice$ = "Scissors" : break
case "L": humanChoice$ = "Lizard" : break
case "K": humanChoice$ = "Spock" : break
end switch
print "Player chose ", humanChoice$, " and Computer chose ", computerChoice$
for n = 0 to 9
if word$(n, WINNER) = humanChoice$ and word$(n, LOSSER) = computerChoice$ then
SimonSay(n)
print "Winner was Player"
wp = wp + 1
break
elseif word$(n, WINNER) = computerChoice$ and word$(n, LOSSER) = humanChoice$ then
SimonSay(n)
print "Winner was Computer"
wc = wc + 1
break
end if
next n
if n = 10 then
print "Ouch!"
end if
punctuation()
print "\nPress any key to continue"
inkey$
until(k$ = "Q")
punctuation()
if wp > wc then
print "Player win"
elseif wc > wp then
print "Computer win"
else
print "Tie"
end if
end
sub SimonSay(n)
print word$(n, WINNER), " ", word$(n, ACTION), " ", word$(n, LOSSER)
end sub
sub punctuation()
print "\nPlayer = ", wp, "\tComputer = ", wc, "\n"
end sub
data "Scissors","cuts","Paper"
data "Paper","covers","Rock"
data "Rock","crushes","Lizard"
data "Lizard","poisons","Spock"
data "Spock","smashes","Scissors"
data "Scissors","decapites","Lizard"
data "Lizard","eats","Paper"
data "Paper","disproves","Spock"
data "Spock","vaporizes","Rock"
data "Rock","blunts","Scissors"</lang>
rules dictionary is of the form 'this': beaten by 'that', etc as opposed to 'this': beats 'that'.
- allows the human player to abbreviate their choice
- issues appropriate error messages for an incorrect (or no) choice(s)
- allows the human player to QUIT at any time
- keeps track of the human player's responses (to hopefully make future computer winning choices)
- uses better "English"/grammer, i.e.: rock breaks scissors, and paper covers rock.
- output with various responses from the user (output shown is a screen scraping):
- output is similar to the 1st REXX version.
- Output:
- Output:
- Enter 'r', 'p', or 's' as your play.
- Enter 'q' to exit the game.
- Running score shown as <your wins>:<my wins>
- Choices are represented by integers, which are indices into this list:
- Rock, Paper, Scissors
- Normally, idiomatic Tcl code uses names for these sorts of things, but it
- turns out that using integers simplifies the move-comparison logic.
human_counts=(1 1 1) human_count=3 computer_counts=(0 0 0) games=0 human=0 computer=0
- Programming Tasks
- Games
- Ada
- Aime
- ALGOL 68
- AutoHotkey
- AutoIt
- BASIC
- Bash
- Batch File
- BBC BASIC
- C
- C++
- C sharp
- Clojure
- Jline
- Clojure.data.generators
- Crystal
- D
- Elixir
- Erlang
- Euphoria
- F Sharp
- Factor
- Fortran
- GlovePIE
- Go
- Haskell
- Icon
- Unicon
- Icon Programming Library
- IS-BASIC
- J
- Java
- JavaScript
- Julia
- Kotlin
- Lasso
- Liberty BASIC
- Locomotive Basic
- Lua
- Mathematica
- Mercury
- NS-HUBASIC
- OCaml
- PARI/GP
- Perl
- Perl 6
- Phix
- PHP
- PicoLisp
- PL/I
- Prolog
- PureBasic
- Python
- Rascal
- Racket
- REXX
- Ring
- Ruby
- Run BASIC
- Rust
- Scala
- Seed7
- C examples needing attention
- Examples needing attention
- Sidef
- SuperCollider
- Swift
- Tcl
- TorqueScript
- TI-83 BASIC
- GUISS/Omit
- UBasic/4tH
- UNIX Shell
- Wee Basic
- Yabasic