24 game
You are encouraged to solve this task according to the task description, using any language you may know.
The 24 Game tests one's mental arithmetic.
- Task
Write a program that randomly chooses and displays four digits, each from 1 ──► 9 (inclusive) with repetitions allowed.
The program should prompt for the player to enter an arithmetic expression using just those, and all of those four digits, used exactly once each. The program should check then evaluate the expression.
The goal is for the player to enter an expression that (numerically) evaluates to 24.
- Only the following operators/functions are allowed: multiplication, division, addition, subtraction
- Division should use floating point or rational arithmetic, etc, to preserve remainders.
- Brackets are allowed, if using an infix expression evaluator.
- Forming multiple digit numbers from the supplied digits is disallowed. (So an answer of 12+12 when given 1, 2, 2, and 1 is wrong).
- The order of the digits when given does not have to be preserved.
- Notes
- The type of expression evaluator used is not mandated. An RPN evaluator is equally acceptable for example.
- The task is not for the program to generate the expression, or test whether an expression is even possible.
- Related tasks
- Reference
- The 24 Game on h2g2.
11l
T Error
String message
F (message)
.message = message
T RPNParse
[Float] stk
[Int] digits
F op(f)
I .stk.len < 2
X.throw Error(‘Improperly written expression’)
V b = .stk.pop()
V a = .stk.pop()
.stk.append(f(a, b))
F parse(s)
L(c) s
I c C ‘0’..‘9’
.stk.append(Float(c))
.digits.append(Int(c))
E I c == ‘+’ {.op((a, b) -> a + b)}
E I c == ‘-’ {.op((a, b) -> a - b)}
E I c == ‘*’ {.op((a, b) -> a * b)}
E I c == ‘/’ {.op((a, b) -> a / b)}
E I c != ‘ ’
X.throw Error(‘Wrong char: ’c)
F get_result()
I .stk.len != 1
X.throw Error(‘Improperly written expression’)
R .stk.last
[Int] digits
print(‘Make 24 with the digits:’, end' ‘’)
L 4
V n = random:(1..9)
print(‘ ’n, end' ‘’)
digits.append(n)
print()
V parser = RPNParse()
X.try
parser.parse(input())
V r = parser.get_result()
I sorted(digits) != sorted(parser.digits)
print(‘Error: Not using the given digits’)
E
print(‘Result: ’r)
I r C 23.999<.<24.001
print(‘Good job!’)
E
print(‘Try again.’)
X.catch Error error
print(‘Error: ’error.message)- Output:
The same as in C++.
8th
This is a fully-worked sample of the game in 8th, showing error-detection and user-restriction techniques:
\ Generate four random digits and display to the user
\ then get an expression from the user using +, -, / and * and the digits
\ the result must equal 24
\ http://8th-dev.com/24game.html
\ Only the words in namespace 'game' are available to the player:
ns: game
: + n:+ ;
: - n:- ;
: * n:* ;
: / n:/ ;
ns: G
var random-digits
var user-input
: one-digit \ a -- a
rand n:abs 9 n:mod n:1+ a:push ;
: gen-digits \ - a
[] clone nip \ the clone nip is not needed in versions past 1.0.2...
' one-digit 4 times
' n:cmp a:sort
random-digits ! ;
: prompt-user
cr "The digits are: " . random-digits @ . cr ;
: goodbye
cr "Thanks for playing!\n" . cr 0 die ;
: get-input
70 null con:accept dup user-input !
null? if drop goodbye then ;
: compare-digits
true swap
(
\ inputed-array index
dup >r
a:@
random-digits @ r> a:@ nip
n:= not if
break
swap drop false swap
then
) 0 3 loop drop ;
/^\D*(\d)\D+(\d)\D+(\d)\D+(\d)\D*$/ var, digits-regex
: all-digits?
user-input @ digits-regex @ r:match
null? if drop false else
5 = not if
false
else
\ convert the captured digits in the regex into a sorted array:
digits-regex @
( r:@ >n swap ) 1 4 loop drop
4 a:close ' n:cmp a:sort
compare-digits
then
then ;
: does-eval?
0 user-input @ eval 24 n:=
dup not if
cr "Sorry, that expression is wrong" . cr
then ;
: check-input
reset
all-digits? if
does-eval? if
cr "Excellent! Your expression: \"" .
user-input @ .
"\" worked!" . cr
then
else
cr "You did not use the digits properly, try again." . cr
then ;
: intro quote |
Welcome to the '24 game'!
You will be shown four digits each time. Using only the + - * and / operators
and all the digits (and only the digits), produce the number '24'
Enter your result in 8th syntax, e.g.: 4 4 + 2 1 + *
To quit the game, just hit enter by itself. Enjoy!
| . ;
: start
\ don't allow anything but the desired words
ns:game only
intro
repeat
gen-digits
prompt-user
get-input
check-input
again ;
start
AArch64 Assembly
/* ARM assembly AARCH64 Raspberry PI 3B */
/* program game24_64.s */
/*******************************************/
/* Constantes file */
/*******************************************/
/* for this file see task include a file in language AArch64 assembly*/
.include "../includeConstantesARM64.inc"
.equ NBDIGITS, 4 // digits number
.equ TOTAL, 24
.equ BUFFERSIZE, 100
.equ STACKSIZE, 10 // operator and digits number items in stacks
/*********************************/
/* Initialized data */
/*********************************/
.data
szMessRules: .ascii "24 Game 64 bits.\n"
.ascii "The program will display four randomly-generated \n"
.ascii "single-digit numbers and will then prompt you to enter\n"
.ascii "an arithmetic expression followed by <enter> to sum \n"
.ascii "the given numbers to 24.\n"
.asciz "Exemple : 9+8+3+4 or (7+5)+(3*4) \n\n"
szMessExpr: .asciz "Enter your expression (or type (q)uit to exit or (n) for other digits): \n"
szMessDigits: .asciz "The four digits are @ @ @ @ and the score is 24. \n"
szMessNoDigit: .asciz "Error : One digit is not in digits list !! \n"
szMessSameDigit: .asciz "Error : Two digits are same !! \n"
szMessOK: .asciz "It is OK. \n"
szMessNotOK: .asciz "Error, it is not ok total = @ \n"
szMessErrOper: .asciz "Unknow Operator (+,-,$,/,(,)) \n"
szMessNoparen: .asciz "no opening parenthesis !! \n"
szMessErrParen: .asciz "Error parenthesis number !! \n"
szMessNoalldigits: .asciz "One or more digits not used !!\n"
szMessNewGame: .asciz "New game (y/n) ? \n"
szCarriageReturn: .asciz "\n"
.align 4
qGraine: .quad 123456
/*********************************/
/* UnInitialized data */
/*********************************/
.bss
sZoneConv: .skip 24
sBuffer: .skip BUFFERSIZE
iTabDigit: .skip 8 * NBDIGITS
iTabTopDigit: .skip 8 * NBDIGITS
/*********************************/
/* code section */
/*********************************/
.text
.global main
main: // entry of program
ldr x0,qAdrszMessRules // display rules
bl affichageMess
1:
mov x3,#0
ldr x12,qAdriTabDigit
ldr x11,qAdriTabTopDigit
ldr x5,qAdrszMessDigits
2: // loop generate random digits
mov x0,#8
bl genereraleas
add x0,x0,#1
str x0,[x12,x3,lsl #3] // store in table
mov x1,#0
str x1,[x11,x3,lsl #3] // raz top table
ldr x1,qAdrsZoneConv
bl conversion10 // call decimal conversion
//mov x2,#0
//strb w2,[x1,x0] // reduce size display area with zéro final
mov x0,x5
ldr x1,qAdrsZoneConv // insert conversion in message
bl strInsertAtCharInc
mov x5,x0
add x3,x3,#1
cmp x3,#NBDIGITS // end ?
blt 2b // no -> loop
mov x0,x5
bl affichageMess
3: // loop human entry
ldr x0,qAdrszMessExpr
bl affichageMess
bl saisie // entry
cmp x0,#'q'
beq 100f
cmp x0,#'Q'
beq 100f
cmp x0,#'n'
beq 1b
cmp x0,#'N'
beq 1b
bl evalExpr // expression evaluation
cmp x0,#0 // ok ?
bne 3b // no - > loop
10: // display new game ?
ldr x0,qAdrszCarriageReturn
bl affichageMess
ldr x0,qAdrszMessNewGame
bl affichageMess
bl saisie
cmp x0,#'y'
beq 1b
cmp x0,#'Y'
beq 1b
100: // standard end of the program
mov x0, #0 // return code
mov x8, #EXIT // request to exit program
svc #0 // perform the system call
qAdrszCarriageReturn: .quad szCarriageReturn
qAdrszMessRules: .quad szMessRules
qAdrszMessDigits: .quad szMessDigits
qAdrszMessExpr: .quad szMessExpr
qAdrszMessNewGame: .quad szMessNewGame
qAdrsZoneConv: .quad sZoneConv
qAdriTabDigit: .quad iTabDigit
qAdriTabTopDigit: .quad iTabTopDigit
/******************************************************************/
/* evaluation expression */
/******************************************************************/
/* x0 return 0 if ok -1 else */
evalExpr:
stp x1,lr,[sp,-16]! // save registres
stp x2,x3,[sp,-16]! // save registres
stp x4,x5,[sp,-16]! // save registres
stp x6,x7,[sp,-16]! // save registres
stp x8,x9,[sp,-16]! // save registres
stp x10,fp,[sp,-16]! // save registres
mov x0,#0
ldr x1,qAdriTabTopDigit
mov x2,#0
1: // loop init table top digits
str x0,[x1,x2,lsl #3]
add x2,x2,#1
cmp x2,#NBDIGITS
blt 1b
sub sp,sp,#STACKSIZE * 8 // stack operator
mov fp,sp
sub sp,sp,#STACKSIZE * 8 // stack digit
mov x1,sp
ldr x10,qAdrsBuffer
mov x8,#0 // indice character in buffer
mov x7,#0 // indice digits stack
mov x2,#0 // indice operator stack
mov x9,0
1: // begin loop
ldrb w9,[x10,x8]
cmp x9,#0xA // end expression ?
beq 90f
cmp x9,#' ' // space ?
cinc x8,x8,eq // loop
beq 1b
cmp x9,#'(' // left parenthesis -> store in operator stack
bne 11f
str x9,[fp,x2,lsl 3]
add x2,x2,#1
add x8,x8,#1 // and loop
b 1b
11:
cmp x9,#')' // right parenthesis ?
bne 3f
mov x0,fp // compute operator stack until left parenthesis
sub x2,x2,#1
2:
ldr x6,[fp,x2,lsl 3]
cmp x6,#'(' // left parenthesis
cinc x8,x8,eq // end ?
beq 1b // and loop
sub x7,x7,#1 // last digit
mov x3,x7
bl compute
sub x2,x2,#1
cmp x2,#0
bge 2b
ldr x0,qAdrszMessNoparen // no left parenthesis in stack
bl affichageMess
mov x0,#-1
b 100f
3:
cmp x9,#'+' // addition
beq 4f
cmp x9,#'-' // soustraction
beq 4f
cmp x9,#'*' // multiplication
beq 4f
cmp x9,#'/' // division
beq 4f
b 5f // not operator
4: // control priority and depile stacks
mov x0,fp
mov x3,x7
mov x4,x9
bl depileOper
mov x7,x3
add x8,x8,#1
b 1b // and loop
5: // digit
sub x9,x9,#0x30
mov x0,x9
bl digitControl
cmp x0,#0 // error ?
bne 100f
str x9,[x1,x7,lsl #3] // store digit in digits stack
add x7,x7,#1
add x8,x8,#1
beq 1b
b 100f
90: // compute all stack operators
mov x0,fp
sub x7,x7,#1
91:
subs x2,x2,#1
blt 92f
mov x3,x7
bl compute
sub x7,x7,#1
b 91b
92:
ldr x0,[x1] // total = first value on digits stack
cmp x0,#TOTAL // control total
beq 93f // ok
ldr x1,qAdrsZoneConv
bl conversion10 // call decimal conversion
mov x2,#0
strb w2,[x1,x0]
ldr x0,qAdrszMessNotOK
ldr x1,qAdrsZoneConv // insert conversion in message
bl strInsertAtCharInc
bl affichageMess
mov x0,#-1
b 100f
93: // control use all digits
ldr x1,qAdriTabTopDigit
mov x2,#0
94: // begin loop
ldr x0,[x1,x2,lsl #3] // load top
cmp x0,#0
bne 95f
ldr x0,qAdrszMessNoalldigits
bl affichageMess
mov x0,#-1
b 100f
95:
add x2,x2,#1
cmp x2,#NBDIGITS
blt 94b
96: // display message OK
ldr x0,qAdrszMessOK
bl affichageMess
mov x0,#0
b 100f
100:
add sp,sp,8 * (STACKSIZE *2) // stack algnement
ldp x10,fp,[sp],16 // restaur des 2 registres
ldp x8,x9,[sp],16 // restaur des 2 registres
ldp x6,x7,[sp],16 // restaur des 2 registres
ldp x4,x5,[sp],16 // restaur des 2 registres
ldp x2,x3,[sp],16 // restaur des 2 registres
ldp x1,lr,[sp],16 // restaur des 2 registres
ret
qAdrszMessNoparen: .quad szMessNoparen
qAdrszMessNotOK: .quad szMessNotOK
qAdrszMessOK: .quad szMessOK
qAdrszMessNoalldigits: .quad szMessNoalldigits
/******************************************************************/
/* depile operator */
/******************************************************************/
/* x0 operator stack address */
/* x1 digits stack address */
/* x2 operator indice */
/* x3 digits indice */
/* x4 operator */
/* x2 return a new operator indice */
/* x3 return a new digits indice */
depileOper:
stp x4,lr,[sp,-16]! // save registres
stp x5,x6,[sp,-16]! // save registres
stp x7,x8,[sp,-16]! // save registres
cmp x2,#0 // first operator ?
beq 60f
sub x5,x2,#1
1:
ldr x6,[x0,x5,lsl #3] // load stack operator
cmp x6,x4 // same operators
beq 50f
cmp x6,#'*' // multiplication
beq 50f
cmp x6,#'/' // division
beq 50f
cmp x6,#'-' // soustraction
beq 50f
b 60f
50: // depile operators stack and compute
sub x2,x2,#1
sub x3,x3,#1
bl compute
sub x5,x5,#1
cmp x5,#0
bge 1b
60:
str x4,[x0,x2,lsl #3] // add operator in stack
add x2,x2,#1
100:
ldp x7,x8,[sp],16 // restaur des 2 registres
ldp x5,x6,[sp],16 // restaur des 2 registres
ldp x4,lr,[sp],16 // restaur des 2 registres
ret
/******************************************************************/
/* compute */
/******************************************************************/
/* x0 operator stack address */
/* x1 digits stack address */
/* x2 operator indice */
/* x3 digits indice */
compute:
stp x1,lr,[sp,-16]! // save registres
stp x2,x3,[sp,-16]! // save registres
stp x4,x5,[sp,-16]! // save registres
stp x6,x7,[sp,-16]! // save registres
stp x8,x9,[sp,-16]! // save registres
ldr x6,[x1,x3,lsl 3] // load second digit
sub x5,x3,#1
ldr x7,[x1,x5,lsl 3] // load first digit
ldr x8,[x0,x2,lsl 3] // load operator
cmp x8,#'+'
bne 1f
add x7,x7,x6 // addition
str x7,[x1,x5,lsl 3]
b 100f
1:
cmp x8,#'-'
bne 2f
sub x7,x7,x6 // soustaction
str x7,[x1,x5,lsl 3]
b 100f
2:
cmp x8,#'*'
bne 3f // multiplication
mul x7,x6,x7
str x7,[x1,x5,lsl 3]
b 100f
3:
cmp x8,#'/'
bne 4f
udiv x7,x7,x6 // division
str x7,[x1,x5,lsl 3]
b 100f
4:
cmp x8,#'(' // left parenthesis ?
bne 5f
ldr x0,qAdrszMessErrParen // error
bl affichageMess
mov x0,#-1
b 100f
5:
ldr x0,qAdrszMessErrOper
bl affichageMess
mov x0,#-1
100:
ldp x8,x9,[sp],16 // restaur des 2 registres
ldp x6,x7,[sp],16 // restaur des 2 registres
ldp x4,x5,[sp],16 // restaur des 2 registres
ldp x2,x3,[sp],16 // restaur des 2 registres
ldp x1,lr,[sp],16 // restaur des 2 registres
ret
qAdrszMessErrOper: .quad szMessErrOper
qAdrszMessErrParen: .quad szMessErrParen
/******************************************************************/
/* control digits */
/******************************************************************/
/* x0 return 0 if OK 1 if not digit */
digitControl:
stp x1,lr,[sp,-16]! // save registres
stp x2,x3,[sp,-16]! // save registres
stp x4,x5,[sp,-16]! // save registres
ldr x1,qAdriTabTopDigit
ldr x2,qAdriTabDigit
mov x3,#0
1:
ldr x4,[x2,x3,lsl #3] // load digit
cmp x0,x4 // equal ?
beq 2f // yes
add x3,x3,#1 // no -> loop
cmp x3,#NBDIGITS // end ?
blt 1b
ldr x0,qAdrszMessNoDigit // error
bl affichageMess
mov x0,#1
b 100f
2: // control prev use
ldr x4,[x1,x3,lsl #3]
cmp x4,#0
beq 3f
add x3,x3,#1
cmp x3,#NBDIGITS
blt 1b
ldr x0,qAdrszMessSameDigit
bl affichageMess
mov x0,#1
b 100f
3:
mov x4,#1
str x4,[x1,x3,lsl #3]
mov x0,#0
100:
ldp x4,x5,[sp],16 // restaur des 2 registres
ldp x2,x3,[sp],16 // restaur des 2 registres
ldp x1,lr,[sp],16 // restaur des 2 registres
ret
qAdrszMessNoDigit: .quad szMessNoDigit
qAdrszMessSameDigit: .quad szMessSameDigit
/******************************************************************/
/* string entry */
/******************************************************************/
/* x0 return the first character of human entry */
saisie:
stp x1,lr,[sp,-16]! // save registres
stp x2,x3,[sp,-16]! // save registres
stp x4,x5,[sp,-16]! // save registres
stp x6,x7,[sp,-16]! // save registres
mov x0,STDIN // Linux input console
ldr x1,qAdrsBuffer // buffer address
mov x2,BUFFERSIZE // buffer size
mov x8,READ // request to read datas
svc 0 // call system
ldr x1,qAdrsBuffer // buffer address
ldrb w0,[x1] // load first character
100:
ldp x6,x7,[sp],16 // restaur des 2 registres
ldp x4,x5,[sp],16 // restaur des 2 registres
ldp x2,x3,[sp],16 // restaur des 2 registres
ldp x1,lr,[sp],16 // restaur des 2 registres
ret
qAdrsBuffer: .quad sBuffer
/***************************************************/
/* Generation random number */
/***************************************************/
/* x0 contains limit */
genereraleas:
stp x1,lr,[sp,-16]! // save registres
stp x2,x3,[sp,-16]! // save registres
stp x4,x5,[sp,-16]! // save registres
ldr x4,qAdrqGraine
ldr x2,[x4]
ldr x3,qNbDep1
mul x2,x3,x2
ldr x3,qNbDep2
add x2,x2,x3
str x2,[x4] // maj de la graine pour l appel suivant
cmp x0,#0
beq 100f
add x0,x0,#1
udiv x3,x2,x0
msub x0,x3,x0,x2 // résult = remainder
ldp x4,x5,[sp],16 // restaur des 2 registres
ldp x2,x3,[sp],16 // restaur des 2 registres
ldp x1,lr,[sp],16 // restaur des 2 registres
ret
/*****************************************************/
qAdrqGraine: .quad qGraine
qNbDep1: .quad 0x0019660d
qNbDep2: .quad 0x3c6ef35f
/********************************************************/
/* File Include fonctions */
/********************************************************/
/* for this file see task include a file in language AArch64 assembly */
.include "../includeARM64.inc"ABAP
See 24 game/ABAP
Ada
game24.adb:
with Ada.Float_Text_IO;
with Ada.Text_IO;
with Ada.Numerics.Discrete_Random;
procedure Game_24 is
subtype Digit is Character range '1' .. '9';
package Random_Digit is new Ada.Numerics.Discrete_Random (Digit);
Exp_Error : exception;
Digit_Generator : Random_Digit.Generator;
Given_Digits : array (1 .. 4) of Digit;
Float_Value : constant array (Digit) of Float :=
(1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0);
function Apply_Op (L, R : Float; Op : Character) return Float is
begin
case Op is
when '+' =>
return L + R;
when '-' =>
return L - R;
when '*' =>
return L * R;
when '/' =>
return L / R;
when others =>
Ada.Text_IO.Put_Line ("Unexpected operator: " & Op);
raise Exp_Error;
end case;
end Apply_Op;
function Eval_Exp (E : String) return Float is
Flt : Float;
First : Positive := E'First;
Last : Positive;
function Match_Paren (Start : Positive) return Positive is
Pos : Positive := Start + 1;
Level : Natural := 1;
begin
loop
if Pos > E'Last then
Ada.Text_IO.Put_Line ("Unclosed parentheses.");
raise Exp_Error;
elsif E (Pos) = '(' then
Level := Level + 1;
elsif E (Pos) = ')' then
Level := Level - 1;
exit when Level = 0;
end if;
Pos := Pos + 1;
end loop;
return Pos;
end Match_Paren;
begin
if E (First) = '(' then
Last := Match_Paren (First);
Flt := Eval_Exp (E (First + 1 .. Last - 1));
elsif E (First) in Digit then
Last := First;
Flt := Float_Value (E (First));
else
Ada.Text_IO.Put_Line ("Unexpected character: " & E (First));
raise Exp_Error;
end if;
loop
if Last = E'Last then
return Flt;
elsif Last = E'Last - 1 then
Ada.Text_IO.Put_Line ("Unexpected end of expression.");
raise Exp_Error;
end if;
First := Last + 2;
if E (First) = '(' then
Last := Match_Paren (First);
Flt := Apply_Op (Flt, Eval_Exp (E (First + 1 .. Last - 1)),
Op => E (First - 1));
elsif E (First) in Digit then
Last := First;
Flt := Apply_Op (Flt, Float_Value (E (First)),
Op => E (First - 1));
else
Ada.Text_IO.Put_Line ("Unexpected character: " & E (First));
raise Exp_Error;
end if;
end loop;
end Eval_Exp;
begin
Ada.Text_IO.Put_Line ("24 Game");
Ada.Text_IO.Put_Line ("- Enter Q to Quit");
Ada.Text_IO.Put_Line ("- Enter N for New digits");
Ada.Text_IO.Put_Line ("Note: Operators are evaluated left-to-right");
Ada.Text_IO.Put_Line (" (use parentheses to override)");
Random_Digit.Reset (Digit_Generator);
<<GEN_DIGITS>>
Ada.Text_IO.Put_Line ("Generating 4 digits...");
for I in Given_Digits'Range loop
Given_Digits (I) := Random_Digit.Random (Digit_Generator);
end loop;
<<GET_EXP>>
Ada.Text_IO.Put ("Your Digits:");
for I in Given_Digits'Range loop
Ada.Text_IO.Put (" " & Given_Digits (I));
end loop;
Ada.Text_IO.New_Line;
Ada.Text_IO.Put ("Enter your Expression: ");
declare
Value : Float;
Response : constant String := Ada.Text_IO.Get_Line;
Prev_Ch : Character := ' ';
Unused_Digits : array (Given_Digits'Range) of Boolean :=
(others => True);
begin
if Response = "n" or Response = "N" then
goto GEN_DIGITS;
end if;
if Response = "q" or Response = "Q" then
return;
end if;
-- check input
for I in Response'Range loop
declare
Ch : constant Character := Response (I);
Found : Boolean;
begin
if Ch in Digit then
if Prev_Ch in Digit then
Ada.Text_IO.Put_Line ("Illegal multi-digit number used.");
goto GET_EXP;
end if;
Found := False;
for J in Given_Digits'Range loop
if Unused_Digits (J) and then
Given_Digits (J) = Ch then
Unused_Digits (J) := False;
Found := True;
exit;
end if;
end loop;
if not Found then
Ada.Text_IO.Put_Line ("Illegal number used: " & Ch);
goto GET_EXP;
end if;
elsif Ch /= '(' and Ch /= ')' and Ch /= '+' and
Ch /= '-' and Ch /= '*' and Ch /= '/' then
Ada.Text_IO.Put_Line ("Illegal character used: " & Ch);
goto GET_EXP;
end if;
Prev_Ch := Ch;
end;
end loop;
-- check all digits used
for I in Given_Digits'Range loop
if Unused_Digits (I) then
Ada.Text_IO.Put_Line ("Digit not used: " & Given_Digits (I));
goto GET_EXP;
end if;
end loop;
-- check value
begin
Value := Eval_Exp (Response);
exception
when Exp_Error =>
goto GET_EXP; -- Message displayed by Eval_Exp;
end;
if abs (Value - 24.0) > 0.001 then
Ada.Text_IO.Put ("Value ");
Ada.Float_Text_IO.Put (Value, Fore => 0, Aft => 3, Exp => 0);
Ada.Text_IO.Put_Line (" is not 24!");
goto GET_EXP;
else
Ada.Text_IO.Put_Line ("You won!");
Ada.Text_IO.Put_Line ("Enter N for a new game, or try another solution.");
goto GET_EXP;
end if;
end;
end Game_24;
- Output:
24 Game
- Enter Q to Quit
- Enter N for New digits
Note: Operators are evaluated left-to-right
(use parentheses to override)
Generating 4 digits...
Your Digits: 2 9 5 9
Enter your Expression: 9+9+5-2
Value 21.000 is not 24!
Your Digits: 2 9 5 9
Enter your Expression: N
Generating 4 digits...
Your Digits: 7 7 1 3
Enter your Expression: (7-1)*(7-3)
You won!
Enter N for a new game, or try another solution.
ALGOL 68
Uses infix expressions.
BEGIN # play the 24 game - present the user with 4 digits and invite them to #
# enter an expression using the digits that evaluates to 24 #
[ 0 : 9 ]INT expression digits; # the digits entered by the user #
[ 0 : 9 ]INT puzzle digits; # the digits for the puzzle #
PROC eval = ( STRING expr )REAL: # parses and evaluates expr #
BEGIN
# syntax: expression = term ( ( "+" | "-" ) term )* #
# term = factor ( ( "*" | "/" ) factor ) * #
# factor = "0" | "1" | "2" | ... | "9" #
# | "(" expression ")" #
INT x pos := LWB expr - 1;
INT x end := UPB expr;
BOOL ok := TRUE;
PROC error = ( STRING msg )VOID:
IF ok THEN # this is the firstt error #
ok := FALSE;
print( ( msg, newline ) );
x pos := x end + 1
FI # error # ;
PROC curr ch = CHAR: IF x pos > x end THEN REPR 0 ELSE expr[ x pos ] FI;
PROC next ch = VOID: WHILE x pos +:= 1; curr ch = " " DO SKIP OD;
PROC factor = REAL:
IF curr ch >= "0" AND curr ch <= "9" THEN
INT digit = ABS curr ch - ABS "0";
REAL result = digit;
expression digits[ digit ] +:= 1;
next ch;
result
ELIF curr ch = "(" THEN
next ch;
REAL result = expression;
IF curr ch = ")" THEN
next ch
ELSE
error( """)"" expected after sub-expression" )
FI;
result
ELSE
error( "Unexpected """ + curr ch + """" );
0
FI # factor # ;
PROC term = REAL:
BEGIN
REAL result := factor;
WHILE curr ch = "*" OR curr ch = "/" DO
CHAR op = curr ch;
next ch;
IF op = "*" THEN result *:= factor ELSE result /:= factor FI
OD;
result
END # term # ;
PROC expression = REAL:
BEGIN
REAL result := term;
WHILE curr ch = "+" OR curr ch = "-" DO
CHAR op = curr ch;
next ch;
IF op = "+" THEN result +:= term ELSE result -:= term FI
OD;
result
END # expression # ;
next ch;
IF curr ch = REPR 0 THEN
error( "Missing expression" );
0
ELSE
REAL result = expression;
IF curr ch /= REPR 0 THEN
error( "Unexpected text: """ + expr[ x pos : ] + """ after expression" )
FI;
result
FI
END # eval # ;
WHILE
FOR i FROM 0 TO 9 DO # initialise the digit counts #
expression digits[ i ] := 0;
puzzle digits[ i ] := 0
OD;
print( ( "Enter an expression using these digits:" ) );
FOR i TO 4 DO # pick 4 random digits #
INT digit := 1 + ENTIER ( next random * 9 );
IF digit > 9 THEN digit := 9 FI;
puzzle digits[ digit ] +:= 1;
print( ( whole( digit, - 2 ) ) )
OD;
print( ( " that evaluates to 24: " ) );
# get and check the expression #
STRING expr;
read( ( expr, newline ) );
REAL result = eval( expr );
BOOL same := TRUE;
FOR i FROM 0 TO 9 WHILE same := puzzle digits[ i ] = expression digits[ i ] DO SKIP OD;
IF NOT same THEN
print( ( "That expression didn't contain the puzzle digits", newline ) )
ELIF result = 24 THEN
print( ( "Yes! That expression evaluates to 24", newline ) )
ELSE
print( ( "No - that expression evaluates to ", fixed( result, -8, 4 ), newline ) )
FI;
print( ( newline, "Play again [y/n]? " ) );
STRING play again;
read( ( play again, newline ) );
play again = "y" OR play again = "Y" OR play again = ""
DO SKIP OD
END- Output:
Enter an expression using these digits: 2 5 3 5 that evaluates to 24: (3+5)*(5-2) Yes! That expression evaluates to 24 Play again [y/n]? Enter an expression using these digits: 8 8 6 6 that evaluates to 24: 8+6+8/6 No - that expression evaluates to 15.3333 Play again [y/n]? Enter an expression using these digits: 2 1 5 1 that evaluates to 24: (1+1)*(7+5) That expression didn't contain the puzzle digits Play again [y/n]? n
APL
tfgame←{⎕IO←1
⎕←d←?⍵⍴9
i←⍞
u[⍋u←{⍎¨⍣(0≠≢⍵)⊢⍵}(i∊'1234567890')⊆i]≢d[⍋d]:'nope'
~∧/((~b←i∊'1234567890')/i)∊'+-×÷()':'nope'
24≠⍎i:'nope'
'Yeah!'
}
- Output:
tfgame 4
6 9 4 5
6+9+4+5
Yeah!
tfgame 6
4 9 7 9 1 1
Ummm... I'm too tired.
nope
Applesoft BASIC
This was taken from both the Commodore BASIC and ZX Spectrum Basic solutions.
0 BH = PEEK (104):BL = PEEK (103)
1 GOSUB 1200: CALL - 868
10 LET N$ = ""
20 R = RND ( - ( PEEK (78) + PEEK (79) * 256)): REM RANDOMIZE
30 FOR I = 1 TO 4
40 LET N$ = N$ + STR$ ( INT ( RND (1) * 9) + 1)
50 NEXT I
60 PRINT " PRESS A KEY TO CONTINUE. ";: GET A$
65 LET I$ = "": LET F$ = "": LET P$ = ""
70 HOME
80 PRINT M$M$ SPC( 16)"24 GAME"
90 PRINT M$"ALLOWED CHARACTERS:"M$
100 LET I$ = N$ + "+-*/()"
110 HTAB 20
120 FOR I = 1 TO 10
130 PRINT MID$ (I$,I,1)" ";
140 NEXT I
150 PRINT M$ TAB( 7)"0 TO END"M$
160 INPUT "ENTER THE FORMULA: ";F$
170 IF F$ = "0" THEN END : GOTO 65
180 PRINT M$ TAB( 7)F$" = ";
190 FOR I = 1 TO LEN (F$)
200 LET C$ = MID$ (F$,I,1)
210 IF C$ = " " THEN LET F$ = MID$ (F$,1,I - 1) + MID$ (F$,I + 1): GOTO 250
220 IF C$ = "+" OR C$ = "-" OR C$ = "*" OR C$ = "/" THEN LET P$ = P$ + "O": GOTO 250
230 IF C$ = "(" OR C$ = ")" THEN LET P$ = P$ + C$: GOTO 250
240 LET P$ = P$ + "N"
250 NEXT I
260 RESTORE
270 FOR I = 1 TO 11
280 READ T$
290 IF T$ = P$ THEN LET I = 11
300 NEXT I
310 IF T$ < > P$ THEN INVERSE : PRINT "BAD CONSTRUCTION!"G$M$: NORMAL : GOTO 60
320 FOR I = 1 TO LEN (F$)
330 FOR J = 1 TO 10
340 IF ( MID$ (F$,I,1) = MID$ (I$,J,1)) AND MID$ (F$,I,1) > "0" AND MID$ (F$,I,1) < = "9" THEN LET I$ = MID$ (I$,1,J - 1) + " " + MID$ (I$,J + 1, LEN (I$))
350 NEXT J,I
370 IF MID$ (I$,1,4) < > " " THEN INVERSE : PRINT "INVALID ARGUMENTS!"G$M$: NORMAL : GOTO 60
380 GOSUB 600: REM LET R = VAL(F$)
390 PRINT R" ";
400 IF R < > 24 THEN INVERSE : PRINT "WRONG!"G$M$: NORMAL : GOTO 60
410 INVERSE : PRINT "CORRECT!"M$: NORMAL : GOTO 10
420 DATA"NONONON"
430 DATA"(NON)ONON"
440 DATA"NONO(NON)"
450 DATA"NO(NO(NON))"
460 DATA"((NON)ON)ON"
470 DATA"NO(NON)ON"
480 DATA"(NON)O(NON)"
485 DATA"NO((NON)ON)"
490 DATA"(NONON)ON"
495 DATA"(NO(NON))ON"
500 DATA"NO(NONON)"
600 REMGET BASIC TO EVALUATE OUR EXPRESSION
605 A$ = "R=" + F$: GOSUB 1440
610 FOR I = 1 TO LEN (A$)
615 REMSIMPLE TOKEN TRANSLATION
620 B = ASC ( MID$ (A$,I,1))
625 IF (B > 41 AND B < 48) OR B = 61 OR B = 94 THEN B = T(B)
630 POKE (AD + I - 1),B
635 NEXT
640 GOSUB 2000
645 REM GOSUB 1440:REM UNCOMMENT TO CLEAR EVALUATION LINE AFTER USE
650 RETURN
1200 M$ = CHR$ (13)
1210 G$ = CHR$ (7)
1220 HOME
1230 PRINT SPC( 16)"24 GAME"
1240 PRINT M$" THE GOAL OF THIS GAME IS TO FORMULATE"
1250 PRINT M$" AN ARITHMETIC EXPRESSION THAT"
1260 PRINT M$" EVALUATES TO A VALUE OF 24, HOWEVER"
1270 PRINT M$" YOU MAY USE ONLY THE FOUR NUMBERS"
1280 PRINT M$" GIVEN AT RANDOM BY THE COMPUTER AND"
1290 PRINT M$" THE STANDARD ARITHMETIC OPERATIONS OF"
1300 PRINT M$" ADD, SUBTRACT, MULTIPLY, AND DIVIDE."
1310 PRINT M$" EACH DIGIT MUST BE USED BY ITSELF. "
1320 PRINT M$" (E.G. IF GIVEN 1, 2, 3, 4, YOU CANNOT"
1330 PRINT M$" COMBINE 1 AND 2 TO MAKE 12.)"
1340 PRINT M$
1350 PRINT "INITIALIZING...";
1360 HTAB 1
1400 DIM T(94)
1401 T( ASC ("+")) = 200: REM $C8
1402 T( ASC ("-")) = 201: REM $C9
1403 T( ASC ("*")) = 202: REM $CA
1404 T( ASC ("/")) = 203: REM $CB
1405 T( ASC ("=")) = 208: REM $D0
1406 T( ASC ("^")) = 204: REM $CC
1409 REMLOCATE LINE 2005 IN RAM
1410 LH = BH:LL = BL:NH = 0:NL = 0
1415 AD = LH * 256 + LL
1420 LH = PEEK (AD + 1):LL = PEEK (AD)
1425 NL = PEEK (AD + 2):NH = PEEK (AD + 3):N = NH * 256 + NL
1430 IF N < > 2005 THEN GOTO 1415
1435 AD = AD + 4: RETURN
1440 FOR J = AD TO AD + 12: POKE J, ASC (":"): NEXT
1445 RETURN
2000 REMPUT 13 COLONS ON THE NEXT LINE
2005 :::::::::::::
2010 RETURNArgile
use std, array, list
do
generate random digits
show random digits
let result = parse expression (get input line)
if result != ERROR
if some digits are unused
print "Wrong ! (you didn't use all digits)" ; failure++
else if result == 24.0
print "Correct !" ; success++
else
print "Wrong ! (you got "result")" ; failure++
while play again ?
print "success:"success" failure:"failure" total:"(success+failure) as int
let success = 0, failure = 0.
.: generate random digits :.
our nat seed = 0xc6f31 (: default seed when /dev/urandom doesn't exist :)
let urandom = fopen "/dev/urandom" "r"
if urandom isn't nil
fread &seed size of seed 1 urandom
fclose urandom
Cfunc srandom seed
seed = (Cfunc random) as nat
for each (val int d) from 0 to 3
digits[d] = '1' + (seed % 9)
seed /= 9
let digits be an array of 4 byte
.: show random digits :.
print "Enter an expression that equates to 24 using only all these digits:"
printf "%c , %c , %c , %c\n"(digits[0])(digits[1])(digits[2])(digits[3])
printf "24 = "
.: some digits are unused :. -> bool
for each (val int d) from 0 to 3
return true if digits[d] != '\0'
false
.: get input line :. -> text
our array of 64 byte line
Cfunc fgets (line) (size of line) (stdin)
let int i
for (i = 0) (line[i] != 0) (i++)
line[i] = '\0' if (line[i] == '\n')
line as text
.: play again ? :. -> bool
while true
printf "Play again ? (y/n) " ; Cfunc fflush stdout
let answer = get input line
switch answer[0]
case 'n' {return false}
case 'y' {return true }
default {continue }
false
=: ERROR := -> real {-32202.0}
.: parse expression <text expr> :. -> real
let x = 0.0, x_is_set = false, op = ' '.
let stack be a list of State ; class State {byte op; real x}
for (stack = nil) (*expr != 0) (expr++)
switch *expr
case '+' ; case '-' ; case '*' ; case '/'
error "bad syntax" if not x_is_set
op = *expr
case '1' ; case '2' ; case '3' ; case '4' ; case '5'
case '6' ; case '7' ; case '8' ; case '9'
error "missing operator" if (x_is_set and op == ' ')
error "unavailable digit" unless consume digit expr[0]
do operation with (expr[0] - '0') as real
case (Cgen "'('")
error "missing operator" if (op == ' ' but x_is_set)
(new list (new State) (code of del State())) << stack
op = ' ' ; x_is_set = false (: start fresh state :)
case (Cgen "')'")
error "mismatched parenthesis" if stack is nil
error "wrong syntax" if not x_is_set
let y = x
x = stack.data.x ; op = stack.data.op
delete pop stack
do operation with y
default {error "disallowed character"}
.:new State :. -> State {let s=new(State); s.x=x; s.op=op; s}
.:del State <State s>:. { free s }
.:do operation with <real y>:.
switch op
case '+' {x += y}
case '-' {x -= y}
case '*' {x *= y}
case '/' {x /= y}
default {x = y; x_is_set = true}
op = ' '
=:error<text msg>:= ->real {eprint "Error: "msg" at ["expr"]";return ERROR}
.:consume digit <byte b>:. -> bool
for each (val int d) from 0 to 3
if digits[d] == b
digits[d] = '\0'
return true
false
if stack isn't nil
delete all stack
error "unclosed parenthesis"
return xcompile with: arc 24_game.arg -o 24_game.c && gcc 24_game.c -o 24_game /usr/lib/libargrt.a
ARM Assembly
/* ARM assembly Raspberry PI */
/* program game24.s */
/* REMARK 1 : this program use routines in a include file
see task Include a file language arm assembly
for the routine affichageMess conversion10
see at end of this program the instruction include */
/* for constantes see task include a file in arm assembly */
/************************************/
/* Constantes */
/************************************/
.include "../constantes.inc"
.equ STDIN, 0 @ Linux input console
.equ READ, 3 @ Linux syscall
.equ NBDIGITS, 4 @ digits number
.equ TOTAL, 24
.equ BUFFERSIZE, 100
.equ STACKSIZE, 10 @ operator and digits number items in stacks
/*********************************/
/* Initialized data */
/*********************************/
.data
szMessRules: .ascii "24 Game\n"
.ascii "The program will display four randomly-generated \n"
.ascii "single-digit numbers and will then prompt you to enter\n"
.ascii "an arithmetic expression followed by <enter> to sum \n"
.ascii "the given numbers to 24.\n"
.asciz "Exemple : 9+8+3+4 or (7+5)+(3*4) \n\n"
szMessExpr: .asciz "Enter your expression (or type (q)uit to exit or (n) for other digits): \n"
//szMessErrChoise: .asciz "invalid choice.\n "
szMessDigits: .asciz "The four digits are @ @ @ @ and the score is 24. \n"
szMessNoDigit: .asciz "Error : One digit is not in digits list !! \n"
szMessSameDigit: .asciz "Error : Two digits are same !! \n"
szMessOK: .asciz "It is OK. \n"
szMessNotOK: .asciz "Error, it is not ok total = @ \n"
szMessErrOper: .asciz "Unknow Operator (+,-,$,/,(,)) \n"
szMessNoparen: .asciz "no opening parenthesis !! \n"
szMessErrParen: .asciz "Error parenthesis number !! \n"
szMessNoalldigits: .asciz "One or more digits not used !!\n"
szMessNewGame: .asciz "New game (y/n) ? \n"
szCarriageReturn: .asciz "\n"
.align 4
iGraine: .int 123456
/*********************************/
/* UnInitialized data */
/*********************************/
.bss
sZoneConv: .skip 24
sBuffer: .skip BUFFERSIZE
iTabDigit: .skip 4 * NBDIGITS
iTabTopDigit: .skip 4 * NBDIGITS
/*********************************/
/* code section */
/*********************************/
.text
.global main
main: @ entry of program
ldr r0,iAdrszMessRules @ display rules
bl affichageMess
1:
mov r3,#0
ldr r12,iAdriTabDigit
ldr r11,iAdriTabTopDigit
ldr r5,iAdrszMessDigits
2: @ loop generate random digits
mov r0,#8
bl genereraleas
add r0,r0,#1
str r0,[r12,r3,lsl #2] @ store in table
mov r1,#0
str r1,[r11,r3,lsl #2] @ raz top table
ldr r1,iAdrsZoneConv
bl conversion10 @ call decimal conversion
mov r2,#0
strb r2,[r1,r0] @ reduce size display area with zéro final
mov r0,r5
ldr r1,iAdrsZoneConv @ insert conversion in message
bl strInsertAtCharInc
mov r5,r0
add r3,r3,#1
cmp r3,#NBDIGITS @ end ?
blt 2b @ no -> loop
mov r0,r5
bl affichageMess
3: @ loop human entry
ldr r0,iAdrszMessExpr
bl affichageMess
bl saisie @ entry
cmp r0,#'q'
beq 100f
cmp r0,#'Q'
beq 100f
cmp r0,#'n'
beq 1b
cmp r0,#'N'
beq 1b
bl evalExpr @ expression evaluation
cmp r0,#0 @ ok ?
bne 3b @ no - > loop
10: @ display new game ?
ldr r0,iAdrszCarriageReturn
bl affichageMess
ldr r0,iAdrszMessNewGame
bl affichageMess
bl saisie
cmp r0,#'y'
beq 1b
cmp r0,#'Y'
beq 1b
100: @ standard end of the program
mov r0, #0 @ return code
mov r7, #EXIT @ request to exit program
svc #0 @ perform the system call
iAdrszCarriageReturn: .int szCarriageReturn
iAdrszMessRules: .int szMessRules
iAdrszMessDigits: .int szMessDigits
iAdrszMessExpr: .int szMessExpr
iAdrszMessNewGame: .int szMessNewGame
iAdrsZoneConv: .int sZoneConv
iAdriTabDigit: .int iTabDigit
iAdriTabTopDigit: .int iTabTopDigit
/******************************************************************/
/* evaluation expression */
/******************************************************************/
/* r0 return 0 if ok -1 else */
evalExpr:
push {r1-r11,lr} @ save registers
mov r0,#0
ldr r1,iAdriTabTopDigit
mov r2,#0
1: @ loop init table top digits
str r0,[r1,r2,lsl #2]
add r2,r2,#1
cmp r2,#NBDIGITS
blt 1b
sub sp,sp,#STACKSIZE * 4 @ stack operator
mov fp,sp
sub sp,sp,#STACKSIZE * 4 @ stack digit
mov r1,sp
ldr r10,iAdrsBuffer
mov r8,#0 @ indice character in buffer
mov r7,#0 @ indice digits stack
mov r2,#0 @ indice operator stack
1: @ begin loop
ldrb r9,[r10,r8]
cmp r9,#0xA @ end expression ?
beq 90f
cmp r9,#' ' @ space ?
addeq r8,r8,#1 @ loop
beq 1b
cmp r9,#'(' @ left parenthesis -> store in operator stack
streq r9,[fp,r2,lsl #2]
addeq r2,r2,#1
addeq r8,r8,#1 @ and loop
beq 1b
cmp r9,#')' @ right parenthesis ?
bne 3f
mov r0,fp @ compute operator stack until left parenthesis
sub r2,r2,#1
2:
ldr r6,[fp,r2,lsl #2]
cmp r6,#'(' @ left parenthesis
addeq r8,r8,#1 @ end ?
beq 1b @ and loop
sub r7,r7,#1 @ last digit
mov r3,r7
bl compute
sub r2,r2,#1
cmp r2,#0
bge 2b
ldr r0,iAdrszMessNoparen @ no left parenthesis in stack
bl affichageMess
mov r0,#-1
b 100f
3:
cmp r9,#'+' @ addition
beq 4f
cmp r9,#'-' @ soustraction
beq 4f
cmp r9,#'*' @ multiplication
beq 4f
cmp r9,#'/' @ division
beq 4f
b 5f @ not operator
4: @ control priority and depile stacks
mov r0,fp
mov r3,r7
mov r4,r9
bl depileOper
mov r7,r3
add r8,r8,#1
b 1b @ and loop
5: @ digit
sub r9,r9,#0x30
mov r0,r9
bl digitControl
cmp r0,#0 @ error ?
bne 100f
str r9,[r1,r7,lsl #2] @ store digit in digits stack
add r7,r7,#1
add r8,r8,#1
beq 1b
b 100f
90: @ compute all stack operators
mov r0,fp
sub r7,r7,#1
91:
subs r2,r2,#1
blt 92f
mov r3,r7
bl compute
sub r7,r7,#1
b 91b
92:
ldr r0,[r1] @ total = first value on digits stack
cmp r0,#TOTAL @ control total
beq 93f @ ok
ldr r1,iAdrsZoneConv
bl conversion10 @ call decimal conversion
mov r2,#0
strb r2,[r1,r0]
ldr r0,iAdrszMessNotOK
ldr r1,iAdrsZoneConv @ insert conversion in message
bl strInsertAtCharInc
bl affichageMess
mov r0,#-1
b 100f
93: @ control use all digits
ldr r1,iAdriTabTopDigit
mov r2,#0
94: @ begin loop
ldr r0,[r1,r2,lsl #2] @ load top
cmp r0,#0
bne 95f
ldr r0,iAdrszMessNoalldigits
bl affichageMess
mov r0,#-1
b 100f
95:
add r2,r2,#1
cmp r2,#NBDIGITS
blt 94b
96: @ display message OK
ldr r0,iAdrszMessOK
bl affichageMess
mov r0,#0
b 100f
100:
add sp,sp,#80 @ stack algnement
pop {r1-r11,lr}
bx lr @ return
iAdrszMessNoparen: .int szMessNoparen
iAdrszMessNotOK: .int szMessNotOK
iAdrszMessOK: .int szMessOK
iAdrszMessNoalldigits: .int szMessNoalldigits
/******************************************************************/
/* depile operator */
/******************************************************************/
/* r0 operator stack address */
/* r1 digits stack address */
/* r2 operator indice */
/* r3 digits indice */
/* r4 operator */
/* r2 return a new operator indice */
/* r3 return a new digits indice */
depileOper:
push {r4-r8,lr} @ save registers
cmp r2,#0 @ first operator ?
beq 60f
sub r5,r2,#1
1:
ldr r6,[r0,r5,lsl #2] @ load stack operator
cmp r6,r4 @ same operators
beq 50f
cmp r6,#'*' @ multiplication
beq 50f
cmp r6,#'/' @ division
beq 50f
cmp r6,#'-' @ soustraction
beq 50f
b 60f
50: @ depile operators stack and compute
sub r2,r2,#1
sub r3,r3,#1
bl compute
sub r5,r5,#1
cmp r5,#0
bge 1b
60:
str r4,[r0,r2,lsl #2] @ add operator in stack
add r2,r2,#1
100:
pop {r4-r8,lr}
bx lr @ return
/******************************************************************/
/* compute */
/******************************************************************/
/* r0 operator stack address */
/* r1 digits stack address */
/* r2 operator indice */
/* r3 digits indice */
compute:
push {r1-r8,lr} @ save registers
ldr r6,[r1,r3,lsl #2] @ load second digit
sub r5,r3,#1
ldr r7,[r1,r5,lsl #2] @ load first digit
ldr r8,[r0,r2,lsl #2] @ load operator
cmp r8,#'+'
bne 1f
add r7,r7,r6 @ addition
str r7,[r1,r5,lsl #2]
b 100f
1:
cmp r8,#'-'
bne 2f
sub r7,r7,r6 @ soustaction
str r7,[r1,r5,lsl #2]
b 100f
2:
cmp r8,#'*'
bne 3f @ multiplication
mul r7,r6,r7
str r7,[r1,r5,lsl #2]
b 100f
3:
cmp r8,#'/'
bne 4f
udiv r7,r7,r6 @ division
str r7,[r1,r5,lsl #2]
b 100f
4:
cmp r8,#'(' @ left parenthesis ?
bne 5f
ldr r0,iAdrszMessErrParen @ error
bl affichageMess
mov r0,#-1
b 100f
5:
ldr r0,iAdrszMessErrOper
bl affichageMess
mov r0,#-1
100:
pop {r1-r8,lr}
bx lr @ return
iAdrszMessErrOper: .int szMessErrOper
iAdrszMessErrParen: .int szMessErrParen
/******************************************************************/
/* control digits */
/******************************************************************/
/* r0 return 0 if OK 1 if not digit */
digitControl:
push {r1-r4,lr} @ save registers
ldr r1,iAdriTabTopDigit
ldr r2,iAdriTabDigit
mov r3,#0
1:
ldr r4,[r2,r3,lsl #2] @ load digit
cmp r0,r4 @ equal ?
beq 2f @ yes
add r3,r3,#1 @ no -> loop
cmp r3,#NBDIGITS @ end ?
blt 1b
ldr r0,iAdrszMessNoDigit @ error
bl affichageMess
mov r0,#1
b 100f
2: @ control prev use
ldr r4,[r1,r3,lsl #2]
cmp r4,#0
beq 3f
add r3,r3,#1
cmp r3,#NBDIGITS
blt 1b
ldr r0,iAdrszMessSameDigit
bl affichageMess
mov r0,#1
b 100f
3:
mov r4,#1
str r4,[r1,r3,lsl #2]
mov r0,#0
100:
pop {r1-r4,lr}
bx lr @ return
iAdrszMessNoDigit: .int szMessNoDigit
iAdrszMessSameDigit: .int szMessSameDigit
/******************************************************************/
/* string entry */
/******************************************************************/
/* r0 return the first character of human entry */
saisie:
push {r1-r7,lr} @ save registers
mov r0,#STDIN @ Linux input console
ldr r1,iAdrsBuffer @ buffer address
mov r2,#BUFFERSIZE @ buffer size
mov r7,#READ @ request to read datas
svc 0 @ call system
ldr r1,iAdrsBuffer @ buffer address
ldrb r0,[r1] @ load first character
100:
pop {r1-r7,lr}
bx lr @ return
iAdrsBuffer: .int sBuffer
/***************************************************/
/* Generation random number */
/***************************************************/
/* r0 contains limit */
genereraleas:
push {r1-r4,lr} @ save registers
ldr r4,iAdriGraine
ldr r2,[r4]
ldr r3,iNbDep1
mul r2,r3,r2
ldr r3,iNbDep2
add r2,r2,r3
str r2,[r4] @ maj de la graine pour l appel suivant
cmp r0,#0
beq 100f
add r1,r0,#1 @ divisor
mov r0,r2 @ dividende
bl division
mov r0,r3 @ résult = remainder
100: @ end function
pop {r1-r4,lr} @ restaur registers
bx lr @ return
/*****************************************************/
iAdriGraine: .int iGraine
iNbDep1: .int 0x343FD
iNbDep2: .int 0x269EC3
/***************************************************/
/* ROUTINES INCLUDE */
/***************************************************/
.include "../affichage.inc"
24 Game The program will display four randomly-generated single-digit numbers and will then prompt you to enter an arithmetic expression followed by <enter> to sum the given numbers to 24. Exemple : 9+8+3+4 or (7+5)+(3*4) The four digits are 5 1 1 5 and the score is 24. Enter your expression (or type (q)uit to exit or (n) for other digits): n The four digits are 8 2 5 3 and the score is 24. Enter your expression (or type (q)uit to exit or (n) for other digits): (8*2)+5+3 It is OK. New game (y/n) ?
Arturo
print "-----------------------------"
print " Welcome to 24 Game"
print "-----------------------------"
digs: map 1..4 'x -> random 1 9
print ["The numbers you can use are:" join.with:" " digs]
print ""
validExpression?: function [expr][
loop expr 'item [
if or? inline? item block? item [
if not? validExpression? item -> return false
]
if symbol? item [
if not? contains? [+ / - *] item -> return false
]
if integer? item [
if not? contains? digs item -> return false
]
]
return true
]
result: 0
while [result<>24][
got: input "Enter an expression to form 24: "
blo: to :block got
if? validExpression? blo [
result: do blo
print ["The result is:" result]
]
else [
print "Invalid expression. Please try again!"
]
print ""
]
print "Well done!"
- Output:
----------------------------- Welcome to 24 Game ----------------------------- The numbers you can use are: 3 2 2 1 Enter an expression to form 24: 3+2+2+1\ Invalid expression. Please try again! Enter an expression to form 24: 3+2+2+1 The result is: 8 Enter an expression to form 24: (3+3+3+3+3)+2+2+1+1 The result is: 21 Enter an expression to form 24: (3+3+3+3+3)+2+2+1+1+1 The result is: 22 Enter an expression to form 24: 3+3+3+3+3+2+2+2+2+1+1 The result is: 25 Enter an expression to form 24: 3+3+3+3+3+2+2+2+2+1 The result is: 24 Well done!
AutoHotkey
AutoExecute:
Title := "24 Game"
Gui, -MinimizeBox
Gui, Add, Text, w230 vPuzzle
Gui, Add, Edit, wp vAnswer
Gui, Add, Button, w70, &Generate
Gui, Add, Button, x+10 wp Default, &Submit
Gui, Add, Button, x+10 wp, E&xit
ButtonGenerate: ; new set of numbers
Loop, 4
Random, r%A_Index%, 1, 9
Puzzle = %r1%, %r2%, %r3%, and %r4%
GuiControl,, Puzzle, The numbers are: %Puzzle% - Good luck!
GuiControl,, Answer ; empty the edit box
ControlFocus, Edit1
Gui, -Disabled
Gui, Show,, %Title%
Return ; end of auto execute section
ButtonSubmit: ; check solution
Gui, Submit, NoHide
Gui, +Disabled
; check numbers used
RegExMatch(Answer, "(\d)\D+(\d)\D+(\d)\D+(\d)", $)
ListPuzzle := r1 "," r2 "," r3 "," r4
ListAnswer := $1 "," $2 "," $3 "," $4
Sort, ListPuzzle, D,
Sort, ListAnswer, D,
If Not ListPuzzle = ListAnswer {
MsgBox, 48, Error - %Title%, Numbers used!`n%Answer%
Goto, TryAgain
}
; check operators used
StringReplace, $, $, +,, All
StringReplace, $, $, -,, All
StringReplace, $, $, *,, All
StringReplace, $, $, /,, All
StringReplace, $, $, (,, All
StringReplace, $, $, ),, All
Loop, 9
StringReplace, $, $, %A_Index%,, All
If StrLen($) > 0
Or InStr(Answer, "**")
Or InStr(Answer, "//")
Or InStr(Answer, "++")
Or InStr(Answer, "--") {
MsgBox, 48, Error - %Title%, Operators used!`n%Answer%
Goto, TryAgain
}
; check result
Result := Eval(Answer)
If Not Result = 24 {
MsgBox, 48, Error - %Title%, Result incorrect!`n%Result%
Goto, TryAgain
}
; if we are sill here
MsgBox, 4, %Title%, Correct solution! Play again?
IfMsgBox, Yes
Gosub, ButtonGenerate
Else
ExitApp
Return
TryAgain: ; alternative ending of routine ButtonSubmit
ControlFocus, Edit1
Gui, -Disabled
Gui, Show
Return
GuiClose:
GuiEscape:
ButtonExit:
ExitApp
Return
;---------------------------------------------------------------------------
Eval(Expr) { ; evaluate expression using separate AHK process
;---------------------------------------------------------------------------
; credit for this function goes to AutoHotkey forum member Laszlo
; http://www.autohotkey.com/forum/topic9578.html
;-----------------------------------------------------------------------
static File := "24$Temp.ahk"
; delete old temporary file, and write new
FileDelete, %File%
FileContent := "#NoTrayIcon`r`n"
. "FileDelete, " File "`r`n"
. "FileAppend, `% " Expr ", " File "`r`n"
FileAppend, %FileContent%, %File%
; run AHK to execute temp script, evaluate expression
RunWait, %A_AhkPath% %File%
; get result
FileRead, Result, %File%
FileDelete, %File%
Return, Result
}
AutoIt
;AutoIt Script Example
;by Daniel Barnes
;spam me at djbarnes at orcon dot net dot en zed
;13/08/2012
;Choose four random digits (1-9) with repetitions allowed:
global $digits
FOR $i = 1 TO 4
$digits &= Random(1,9,1)
NEXT
While 1
main()
WEnd
Func main()
$text = "Enter an equation (using all of, and only, the single digits "&$digits &")"&@CRLF
$text &= "which evaluates to exactly 24. Only multiplication (*) division (/)"&@CRLF
$text &= "addition (+) and subtraction (-) operations and parentheses are allowed:"
$input = InputBox ("24 Game",$text,"","",400,150)
If @error Then exit
;remove any spaces in input
$input = StringReplace($input," ","")
;check correct characters were used
For $i = 1 To StringLen($input)
$chr = StringMid($input,$i,1)
If Not StringInStr("123456789*/+-()",$chr) Then
MsgBox (0, "ERROR","Invalid character used: '"&$chr&"'")
return
endif
Next
;validate the equation uses all of the 4 characters, and nothing else
$test = $input
$test = StringReplace($test,"(","")
$test = StringReplace($test,")","")
;validate the length of the input - if its not 7 characters long then the user has done something wrong
If StringLen ($test) <> 7 Then
MsgBox (0,"ERROR","The equation "&$test&" is invalid")
return
endif
$test = StringReplace($test,"/","")
$test = StringReplace($test,"*","")
$test = StringReplace($test,"-","")
$test = StringReplace($test,"+","")
For $i = 1 To StringLen($digits)
$digit = StringMid($digits,$i,1)
For $ii = 1 To StringLen($test)
If StringMid($test,$ii,1) = $digit Then
$test = StringLeft($test,$ii-1) & StringRight($test,StringLen($test)-$ii)
ExitLoop
endif
Next
Next
If $test <> "" Then
MsgBox (0, "ERROR", "The equation didn't use all 4 characters, and nothing else!")
return
endif
$try = Execute($input)
If $try = 24 Then
MsgBox (0, "24 Game","Well done. Your equation ("&$input&") = 24!")
Exit
Else
MsgBox (0, "24 Game","Fail. Your equation ("&$input&") = "&$try&"!")
return
endif
EndFunc
BBC BASIC
REM Choose four random digits (1-9) with repetitions allowed:
DIM digits%(4), check%(4)
FOR choice% = 1 TO 4
digits%(choice%) = RND(9)
NEXT choice%
REM Prompt the player:
PRINT "Enter an equation (using all of, and only, the single digits ";
FOR index% = 1 TO 4
PRINT ; digits%(index%) ;
IF index%<>4 PRINT " " ;
NEXT
PRINT ")"
PRINT "which evaluates to exactly 24. Only multiplication (*), division (/),"
PRINT "addition (+) & subtraction (-) operations and parentheses are allowed:"
INPUT "24 = " equation$
REPEAT
REM Check that the correct digits are used:
check%() = 0
FOR char% = 1 TO LEN(equation$)
digit% = INSTR("0123456789", MID$(equation$, char%, 1)) - 1
IF digit% >= 0 THEN
FOR index% = 1 TO 4
IF digit% = digits%(index%) THEN
IF NOT check%(index%) check%(index%) = TRUE : EXIT FOR
ENDIF
NEXT index%
IF index% > 4 THEN
PRINT "Sorry, you used the illegal digit "; digit%
EXIT REPEAT
ENDIF
ENDIF
NEXT char%
FOR index% = 1 TO 4
IF NOT check%(index%) THEN
PRINT "Sorry, you failed to use the digit " ; digits%(index%)
EXIT REPEAT
ENDIF
NEXT index%
REM Check that no pairs of digits are used:
FOR pair% = 11 TO 99
IF INSTR(equation$, STR$(pair%)) THEN
PRINT "Sorry, you may not use a pair of digits "; pair%
EXIT REPEAT
ENDIF
NEXT pair%
REM Check whether the equation evaluates to 24:
ON ERROR LOCAL PRINT "Sorry, there was an error in the equation" : EXIT REPEAT
result = EVAL(equation$)
RESTORE ERROR
IF result = 24 THEN
PRINT "Congratulations, you succeeded in the task!"
ELSE
PRINT "Sorry, your equation evaluated to " ; result " rather than 24!"
ENDIF
UNTIL TRUE
INPUT '"Play again", answer$
IF LEFT$(answer$,1) = "y" OR LEFT$(answer$,1) = "Y" THEN CLS : RUN
QUIT
Befunge
v > > >> v
2 2 1234
4 ^1?3^4
>8*00p10p> >? ?5> 68*+00g10gpv
v9?7v6 0
8 0
> > >> ^ g
^p00 _v# `\*49:+1 <
_>"rorrE",,,,,$ >~:67*-!#v_:167*+-!#v_:95*-!#v_:295*+-!#v_:586*+\`#v_:97*2--!#v
$ $ $ $ : $
* + - / 1 :
^ < < < < 8 .
6 6
* 4
+ *
\ -
` > v_v
"
^ < _v e
^ _^#+*28:p2\*84\-*86g2:-+*441< s
o
L
> 1 |-*49"#<
| -*84gg01g00<p00*84<v <
>00g:1+00p66*`#^_ "niW">:#,_@
The code functions by placing the 4 randomly generated numbers into the points labelled 1,2,3,4. In order to play, press the corresponding label to draw that number onto the stack, then press the corresponding operation (+,-,*,/) to perform it on the stack elements postfix-wise according to the rules of befunge (i.e. pop the values operate and push the answer back to the stack). When you wish to check your answer enter "=" and it will perform the checks to ensure that you haven't performed any illegal operations, that you have used all four numbers and that your final value is 24.
Unfortunately, due to the lack of floating-point arithmetic in befunge, divide will result in the answer truncated to an integer.
Example: 6566
213/-4*=
- Output:
24 Win
Bracmat
( 24-game
= m-w m-z 4numbers answer expr numbers
, seed get-random convertBinaryMinusToUnary
, convertDivisionToMultiplication isExpresssion reciprocal
. (seed=.!arg:(~0:~/#?m-w.~0:~/#?m-z))
& seed$!arg
& ( get-random
=
. 36969*mod$(!m-z.65536)+div$(!m-z.65536):?m-z
& 18000*mod$(!m-w.65536)+div$(!m-w.65536):?m-w
& mod$(!m-z*65536+!m-w.9)+1
)
& ( convertBinaryMinusToUnary
= a z
. @(!arg:%?a "-" ?z)
& str$(!a "+-1*" convertBinaryMinusToUnary$!z)
| !arg
)
& (reciprocal=.!arg^-1)
& ( convertDivisionToMultiplication
= a z
. @(!arg:?a "/" ?z)
& str$(!a "*reciprocal$" convertDivisionToMultiplication$!z)
| !arg
)
& ( isExpresssion
= A Z expr
. @( !arg
: ?A
("+"|"-"|"*"|"/")
( ?Z
& isExpresssion$!A
& isExpresssion$!Z
)
)
| !numbers:?A !arg ?Z
& !A !Z:?numbers
| ( @(!arg:"(" ?expr ")")
| @(!arg:(" "|\t) ?expr)
| @(!arg:?expr (" "|\t))
)
& isExpresssion$!expr
)
& out
$ "Enter an expression that evaluates to 24 by combining the following numbers."
& out$"You may only use the operators + - * /"
& out$"Parentheses and spaces are allowed."
& whl
' ( get-random$() get-random$() get-random$() get-random$
: ?4numbers
& out$!4numbers
& whl
' ( get'(,STR):?expr:~
& !4numbers:?numbers
& ~(isExpresssion$!expr&!numbers:)
& out
$ ( str
$ ( "["
!expr
"] is not a valid expression. Try another expression."
)
)
)
& !expr:~
& convertBinaryMinusToUnary$!expr:?expr
& convertDivisionToMultiplication$!expr:?expr
& get$(!expr,MEM):?answer
& out$(str$(!expr " = " !answer))
& !answer
: ( 24&out$Right!
| #&out$Wrong!
)
& out$"Try another one:"
)
& out$bye
)
& 24-game$(13.14)
& ;Enter an expression that evaluates to 24 by combining the following numbers. You may only use the operators + - * / Parentheses and spaces are allowed. 4 2 2 7 4*7 - 2-2 4*7 +-1* 2+-1*2 = 24 Right! Try another one: 4 7 9 8 ((4) *(8 - (9- 7)) [((4) *(8 - (9- 7))] is not a valid expression. Try another expression. ((4) *(8 - (9- 7))) ((4) *(8 +-1* (9+-1* 7))) = 24 Right! Try another one: 9 5 8 5 5 * 5 - (9 - 8) 5 * 5 +-1* (9 +-1* 8) = 24 Right! Try another one: 5 9 7 8 5*8 - 9 - 7 5*8 +-1* 9 +-1* 7 = 24 Right! Try another one: 7 8 6 2 8 * ((7 - 6) + 2) 8 * ((7 +-1* 6) + 2) = 24 Right! Try another one: 8 6 8 1 8 * (1 + 8 - 6) 8 * (1 + 8 +-1* 6) = 24 Right! Try another one: 8 2 2 4 8 * (2 + 4)/2 8 * (2 + 4)*reciprocal$2 = 24 Right! Try another one: 8 4 6 7 bye
C
Simple recursive descent parser. It doesn't have a real lexer, because all tokens are single character (digits, operators and parens). Code is a little too long.
#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <setjmp.h>
#include <time.h>
jmp_buf ctx;
const char *msg;
enum { OP_NONE = 0, OP_NUM, OP_ADD, OP_SUB, OP_MUL, OP_DIV };
typedef struct expr_t *expr, expr_t;
struct expr_t {
int op, val, used;
expr left, right;
};
#define N_DIGITS 4
expr_t digits[N_DIGITS];
void gen_digits()
{
int i;
for (i = 0; i < N_DIGITS; i++)
digits[i].val = 1 + rand() % 9;
}
#define MAX_INPUT 64
char str[MAX_INPUT];
int pos;
#define POOL_SIZE 8
expr_t pool[POOL_SIZE];
int pool_ptr;
void reset()
{
int i;
msg = 0;
pool_ptr = pos = 0;
for (i = 0; i < POOL_SIZE; i++) {
pool[i].op = OP_NONE;
pool[i].left = pool[i].right = 0;
}
for (i = 0; i < N_DIGITS; i++)
digits[i].used = 0;
}
/* longish jumpish back to input cycle */
void bail(const char *s)
{
msg = s;
longjmp(ctx, 1);
}
expr new_expr()
{
if (pool_ptr < POOL_SIZE)
return pool + pool_ptr++;
return 0;
}
/* check next input char */
int next_tok()
{
while (isspace(str[pos])) pos++;
return str[pos];
}
/* move input pointer forward */
int take()
{
if (str[pos] != '\0') return ++pos;
return 0;
}
/* BNF(ish)
expr = term { ("+")|("-") term }
term = fact { ("*")|("/") expr }
fact = number
| '(' expr ')'
*/
expr get_fact();
expr get_term();
expr get_expr();
expr get_expr()
{
int c;
expr l, r, ret;
if (!(ret = get_term())) bail("Expected term");
while ((c = next_tok()) == '+' || c == '-') {
if (!take()) bail("Unexpected end of input");
if (!(r = get_term())) bail("Expected term");
l = ret;
ret = new_expr();
ret->op = (c == '+') ? OP_ADD : OP_SUB;
ret->left = l;
ret->right = r;
}
return ret;
}
expr get_term()
{
int c;
expr l, r, ret;
ret = get_fact();
while((c = next_tok()) == '*' || c == '/') {
if (!take()) bail("Unexpected end of input");
r = get_fact();
l = ret;
ret = new_expr();
ret->op = (c == '*') ? OP_MUL : OP_DIV;
ret->left = l;
ret->right = r;
}
return ret;
}
expr get_digit()
{
int i, c = next_tok();
expr ret;
if (c >= '0' && c <= '9') {
take();
ret = new_expr();
ret->op = OP_NUM;
ret->val = c - '0';
for (i = 0; i < N_DIGITS; i++)
if (digits[i].val == ret->val && !digits[i].used) {
digits[i].used = 1;
return ret;
}
bail("Invalid digit");
}
return 0;
}
expr get_fact()
{
int c;
expr l = get_digit();
if (l) return l;
if ((c = next_tok()) == '(') {
take();
l = get_expr();
if (next_tok() != ')') bail("Unbalanced parens");
take();
return l;
}
return 0;
}
expr parse()
{
int i;
expr ret = get_expr();
if (next_tok() != '\0')
bail("Trailing garbage");
for (i = 0; i < N_DIGITS; i++)
if (!digits[i].used)
bail("Not all digits are used");
return ret;
}
typedef struct frac_t frac_t, *frac;
struct frac_t { int denom, num; };
int gcd(int m, int n)
{
int t;
while (m) {
t = m; m = n % m; n = t;
}
return n;
}
/* evaluate expression tree. result in fraction form */
void eval_tree(expr e, frac res)
{
frac_t l, r;
int t;
if (e->op == OP_NUM) {
res->num = e->val;
res->denom = 1;
return;
}
eval_tree(e->left, &l);
eval_tree(e->right, &r);
switch(e->op) {
case OP_ADD:
res->num = l.num * r.denom + l.denom * r.num;
res->denom = l.denom * r.denom;
break;
case OP_SUB:
res->num = l.num * r.denom - l.denom * r.num;
res->denom = l.denom * r.denom;
break;
case OP_MUL:
res->num = l.num * r.num;
res->denom = l.denom * r.denom;
break;
case OP_DIV:
res->num = l.num * r.denom;
res->denom = l.denom * r.num;
break;
}
if ((t = gcd(res->denom, res->num))) {
res->denom /= t;
res->num /= t;
}
}
void get_input()
{
int i;
reinput:
reset();
printf("\nAvailable digits are:");
for (i = 0; i < N_DIGITS; i++)
printf(" %d", digits[i].val);
printf(". Type an expression and I'll check it for you, or make new numbers.\n"
"Your choice? [Expr/n/q] ");
while (1) {
for (i = 0; i < MAX_INPUT; i++) str[i] = '\n';
fgets(str, MAX_INPUT, stdin);
if (*str == '\0') goto reinput;
if (str[MAX_INPUT - 1] != '\n')
bail("string too long");
for (i = 0; i < MAX_INPUT; i++)
if (str[i] == '\n') str[i] = '\0';
if (str[0] == 'q') {
printf("Bye\n");
exit(0);
}
if (str[0] == 'n') {
gen_digits();
goto reinput;
}
return;
}
}
int main()
{
frac_t f;
srand(time(0));
gen_digits();
while(1) {
get_input();
setjmp(ctx); /* if parse error, jump back here with err msg set */
if (msg) {
/* after error jump; announce, reset, redo */
printf("%s at '%.*s'\n", msg, pos, str);
continue;
}
eval_tree(parse(), &f);
if (f.denom == 0) bail("Divide by zero");
if (f.denom == 1 && f.num == 24)
printf("You got 24. Very good.\n");
else {
if (f.denom == 1)
printf("Eval to: %d, ", f.num);
else
printf("Eval to: %d/%d, ", f.num, f.denom);
printf("no good. Try again.\n");
}
}
return 0;
}
- Output:
Available digits are: 5 2 3 9. Type an expression and I'll check it for you, or make new numbers. Your choice? [Expr/n/q] 5*2*3/9 Eval to: 10/3, no good. Try again. Available digits are: 5 2 3 9. Type an expression and I'll check it for you, or make new numbers. Your choice? [Expr/n/q] (5*(2+3)-9 Unbalanced parens at '(5*(2+3)-9' Available digits are: 5 2 3 9. Type an expression and I'll check it for you, or make new numbers. Your choice? [Expr/n/q] 3*9-(5-2) You got 24. Very good. Available digits are: 5 2 3 9. Type an expression and I'll check it for you, or make new numbers. Your choice? [Expr/n/q] n Available digits are: 4 4 4 7. Type an expression and I'll check it for you, or make new numbers. Your choice? [Expr/n/q] q Bye
See 24 game/C
C#
See 24 game/CSharp
C++
This uses the C++11 standard to simplify several parts of the code. Input is given in RPN format.
#include <random>
#include <iostream>
#include <stack>
#include <set>
#include <string>
#include <functional>
using namespace std;
class RPNParse
{
public:
stack<double> stk;
multiset<int> digits;
void op(function<double(double,double)> f)
{
if(stk.size() < 2)
throw "Improperly written expression";
int b = stk.top(); stk.pop();
int a = stk.top(); stk.pop();
stk.push(f(a, b));
}
void parse(char c)
{
if(c >= '0' && c <= '9')
{
stk.push(c - '0');
digits.insert(c - '0');
}
else if(c == '+')
op([](double a, double b) {return a+b;});
else if(c == '-')
op([](double a, double b) {return a-b;});
else if(c == '*')
op([](double a, double b) {return a*b;});
else if(c == '/')
op([](double a, double b) {return a/b;});
}
void parse(string s)
{
for(int i = 0; i < s.size(); ++i)
parse(s[i]);
}
double getResult()
{
if(stk.size() != 1)
throw "Improperly written expression";
return stk.top();
}
};
int main()
{
random_device seed;
mt19937 engine(seed());
uniform_int_distribution<> distribution(1, 9);
auto rnd = bind(distribution, engine);
multiset<int> digits;
cout << "Make 24 with the digits: ";
for(int i = 0; i < 4; ++i)
{
int n = rnd();
cout << " " << n;
digits.insert(n);
}
cout << endl;
RPNParse parser;
try
{
string input;
getline(cin, input);
parser.parse(input);
if(digits != parser.digits)
cout << "Error: Not using the given digits" << endl;
else
{
double r = parser.getResult();
cout << "Result: " << r << endl;
if(r > 23.999 && r < 24.001)
cout << "Good job!" << endl;
else
cout << "Try again." << endl;
}
}
catch(char* e)
{
cout << "Error: " << e << endl;
}
return 0;
}
- Output:
Make 24 with the digits: 1 4 9 9 9 9 + 4 * 1 + Result: 73 Try again. Make 24 with the digits: 3 9 9 2 9 9 + 3 2 * + Result: 24 Good job!
Ceylon
Be sure to import ceylon.random in you ceylon.module file.
import ceylon.random {
DefaultRandom
}
class Rational(shared Integer numerator, shared Integer denominator = 1) satisfies Numeric<Rational> {
assert (denominator != 0);
Integer gcd(Integer a, Integer b) => if (b == 0) then a else gcd(b, a % b);
shared Rational inverted => Rational(denominator, numerator);
shared Rational simplified =>
let (largestFactor = gcd(numerator, denominator))
Rational(numerator / largestFactor, denominator / largestFactor);
divided(Rational other) => (this * other.inverted).simplified;
negated => Rational(-numerator, denominator).simplified;
plus(Rational other) =>
let (top = numerator*other.denominator + other.numerator*denominator,
bottom = denominator * other.denominator)
Rational(top, bottom).simplified;
times(Rational other) =>
Rational(numerator * other.numerator, denominator * other.denominator).simplified;
shared Integer integer => numerator / denominator;
shared Float float => numerator.float / denominator.float;
string => denominator == 1 then numerator.string else "``numerator``/``denominator``";
shared actual Boolean equals(Object that) {
if (is Rational that) {
value simplifiedThis = this.simplified;
value simplifiedThat = that.simplified;
return simplifiedThis.numerator==simplifiedThat.numerator &&
simplifiedThis.denominator==simplifiedThat.denominator;
}
else {
return false;
}
}
}
interface Expression {
shared formal Rational evaluate();
}
class NumberExpression(Rational number) satisfies Expression {
evaluate() => number;
string => number.string;
}
class OperatorExpression(Expression left, Character operator, Expression right) satisfies Expression {
shared actual Rational evaluate() {
switch (operator)
case ('*') {
return left.evaluate() * right.evaluate();
}
case ('/') {
return left.evaluate() / right.evaluate();
}
case ('-') {
return left.evaluate() - right.evaluate();
}
case ('+') {
return left.evaluate() + right.evaluate();
}
else {
throw Exception("unknown operator ``operator``");
}
}
string => "(``left.string`` ``operator.string`` ``right.string``)";
}
"A simplified top down operator precedence parser. There aren't any right
binding operators so we don't have to worry about that."
class PrattParser(String input) {
value tokens = input.replace(" ", "");
variable value index = -1;
shared Expression expression(Integer precedence = 0) {
value token = advance();
variable value left = parseUnary(token);
while (precedence < getPrecedence(peek())) {
value nextToken = advance();
left = parseBinary(left, nextToken);
}
return left;
}
Integer getPrecedence(Character op) =>
switch (op)
case ('*' | '/') 2
case ('+' | '-') 1
else 0;
Character advance(Character? expected = null) {
index++;
value token = tokens[index] else ' ';
if (exists expected, token != expected) {
throw Exception("unknown character ``token``");
}
return token;
}
Character peek() => tokens[index + 1] else ' ';
Expression parseBinary(Expression left, Character operator) =>
let (right = expression(getPrecedence(operator)))
OperatorExpression(left, operator, right);
Expression parseUnary(Character token) {
if (token.digit) {
assert (is Integer int = Integer.parse(token.string));
return NumberExpression(Rational(int));
}
else if (token == '(') {
value exp = expression();
advance(')');
return exp;
}
else {
throw Exception("unknown character ``token``");
}
}
}
shared void run() {
value random = DefaultRandom();
function random4Numbers() =>
random.elements(1..9).take(4).sequence();
function isValidGuess(String input, {Integer*} allowedNumbers) {
value allowedOperators = set { *"()+-/*" };
value extractedNumbers = input
.split((Character ch) => ch in allowedOperators || ch.whitespace)
.map((String element) => Integer.parse(element))
.narrow<Integer>();
if (extractedNumbers.any((Integer element) => element > 9)) {
print("number too big!");
return false;
}
if (extractedNumbers.any((Integer element) => element < 1)) {
print("number too small!");
return false;
}
if (extractedNumbers.sort(increasing) != allowedNumbers.sort(increasing)) {
print("use all the numbers, please!");
return false;
}
if (!input.every((Character element) => element in allowedOperators || element.digit || element.whitespace)) {
print("only digits and mathematical operators, please");
return false;
}
variable value leftParens = 0;
for (c in input) {
if (c == '(') {
leftParens++;
} else if (c == ')') {
leftParens--;
if (leftParens < 0) {
break;
}
}
}
if (leftParens != 0) {
print("unbalanced brackets!");
return false;
}
return true;
}
function evaluate(String input) =>
let (parser = PrattParser(input),
exp = parser.expression())
exp.evaluate();
print("Welcome to The 24 Game.
Create a mathematical equation with four random
numbers that evaluates to 24.
You must use all the numbers once and only once,
but in any order.
Also, only + - / * and parentheses are allowed.
For example: (1 + 2 + 3) * 4
Also: enter n for new numbers and q to quit.
-----------------------------------------------");
value twentyfour = Rational(24);
while (true) {
value chosenNumbers = random4Numbers();
void pleaseTryAgain() => print("Sorry, please try again. (Your numbers are ``chosenNumbers``)");
print("Your numbers are ``chosenNumbers``. Please turn them into 24.");
while (true) {
value line = process.readLine()?.trimmed;
if (exists line) {
if (line.uppercased == "Q") { // quit
print("bye!");
return;
}
if (line.uppercased == "N") { // new game
break;
}
if (isValidGuess(line, chosenNumbers)) {
try {
value result = evaluate(line);
print("= ``result``");
if (result == twentyfour) {
print("You did it!");
break;
}
else {
pleaseTryAgain();
}
}
catch (Exception e) {
print(e.message);
pleaseTryAgain();
}
}
else {
pleaseTryAgain();
}
}
}
}
}
Clojure
(ns rosettacode.24game)
(def ^:dynamic *luser*
"You guessed wrong, or your input was not in prefix notation.")
(def ^:private start #(println
"Your numbers are: " %1 ". Your goal is " %2 ".\n"
"Use the ops [+ - * /] in prefix notation to reach" %2 ".\n"
"q[enter] to quit."))
(defn play
([] (play 24))
([goal] (play goal (repeatedly 4 #(inc (rand-int 9)))))
([goal gns]
(start gns goal)
(let [input (read-string (read-line))
flat (flatten input)]
(println
(if (and (re-find #"^\([\d\s+*/-]+\d?\)$" (pr-str flat))
(= (set gns) (set (filter integer? flat)))
(= goal (eval input)))
"You won the game!"
*luser*))
(when (not= input 'q) (recur goal gns)))))
; * checks prefix form, then checks to see that the numbers used
; and the numbers generated by the game are the same.
COBOL
>>SOURCE FORMAT FREE
*> This code is dedicated to the public domain
*> This is GNUCobol 2.0
identification division.
program-id. twentyfour.
environment division.
configuration section.
repository. function all intrinsic.
data division.
working-storage section.
01 p pic 999.
01 p1 pic 999.
01 p-max pic 999 value 38.
01 program-syntax pic x(494) value
*>statement = expression;
'001 001 000 n'
& '002 000 004 ='
& '003 005 000 n'
& '004 000 002 ;'
*>expression = term, {('+'|'-') term,};
& '005 005 000 n'
& '006 000 016 ='
& '007 017 000 n'
& '008 000 015 {'
& '009 011 013 ('
& '010 001 000 t'
& '011 013 000 |'
& '012 002 000 t'
& '013 000 009 )'
& '014 017 000 n'
& '015 000 008 }'
& '016 000 006 ;'
*>term = factor, {('*'|'/') factor,};
& '017 017 000 n'
& '018 000 028 ='
& '019 029 000 n'
& '020 000 027 {'
& '021 023 025 ('
& '022 003 000 t'
& '023 025 000 |'
& '024 004 000 t'
& '025 000 021 )'
& '026 029 000 n'
& '027 000 020 }'
& '028 000 018 ;'
*>factor = ('(' expression, ')' | digit,);
& '029 029 000 n'
& '030 000 038 ='
& '031 035 037 ('
& '032 005 000 t'
& '033 005 000 n'
& '034 006 000 t'
& '035 037 000 |'
& '036 000 000 n'
& '037 000 031 )'
& '038 000 030 ;'.
01 filler redefines program-syntax.
03 p-entry occurs 038.
05 p-address pic 999.
05 filler pic x.
05 p-definition pic 999.
05 p-alternate redefines p-definition pic 999.
05 filler pic x.
05 p-matching pic 999.
05 filler pic x.
05 p-symbol pic x.
01 t pic 999.
01 t-len pic 99 value 6.
01 terminal-symbols
pic x(210) value
'01 + '
& '01 - '
& '01 * '
& '01 / '
& '01 ( '
& '01 ) '.
01 filler redefines terminal-symbols.
03 terminal-symbol-entry occurs 6.
05 terminal-symbol-len pic 99.
05 filler pic x.
05 terminal-symbol pic x(32).
01 nt pic 999.
01 nt-lim pic 99 value 5.
01 nonterminal-statements pic x(294) value
"000 ....,....,....,....,....,....,....,....,....,"
& "001 statement = expression; "
& "005 expression = term, {('+'|'-') term,}; "
& "017 term = factor, {('*'|'/') factor,}; "
& "029 factor = ('(' expression, ')' | digit,); "
& "036 digit; ".
01 filler redefines nonterminal-statements.
03 nonterminal-statement-entry occurs 5.
05 nonterminal-statement-number pic 999.
05 filler pic x.
05 nonterminal-statement pic x(45).
01 indent pic x(64) value all '| '.
01 interpreter-stack.
03 r pic 99. *> previous top of stack
03 s pic 99. *> current top of stack
03 s-max pic 99 value 32.
03 s-entry occurs 32.
05 filler pic x(2) value 'p='.
05 s-p pic 999. *> callers return address
05 filler pic x(4) value ' sc='.
05 s-start-control pic 999. *> sequence start address
05 filler pic x(4) value ' ec='.
05 s-end-control pic 999. *> sequence end address
05 filler pic x(4) value ' al='.
05 s-alternate pic 999. *> the next alternate
05 filler pic x(3) value ' r='.
05 s-result pic x. *> S success, F failure, N no result
05 filler pic x(3) value ' c='.
05 s-count pic 99. *> successes in a sequence
05 filler pic x(3) value ' x='.
05 s-repeat pic 99. *> repeats in a {} sequence
05 filler pic x(4) value ' nt='.
05 s-nt pic 99. *> current nonterminal
01 language-area.
03 l pic 99.
03 l-lim pic 99.
03 l-len pic 99 value 1.
03 nd pic 9.
03 number-definitions.
05 n occurs 4 pic 9.
03 nu pic 9.
03 number-use.
05 u occurs 4 pic x.
03 statement.
05 c occurs 32.
07 c9 pic 9.
01 number-validation.
03 p4 pic 99.
03 p4-lim pic 99 value 24.
03 permutations-4 pic x(96) value
'1234'
& '1243'
& '1324'
& '1342'
& '1423'
& '1432'
& '2134'
& '2143'
& '2314'
& '2341'
& '2413'
& '2431'
& '3124'
& '3142'
& '3214'
& '3241'
& '3423'
& '3432'
& '4123'
& '4132'
& '4213'
& '4231'
& '4312'
& '4321'.
03 filler redefines permutations-4.
05 permutation-4 occurs 24 pic x(4).
03 current-permutation-4 pic x(4).
03 cpx pic 9.
03 od1 pic 9.
03 od2 pic 9.
03 odx pic 9.
03 od-lim pic 9 value 4.
03 operator-definitions pic x(4) value '+-*/'.
03 current-operators pic x(3).
03 co3 pic 9.
03 rpx pic 9.
03 rpx-lim pic 9 value 4.
03 valid-rpn-forms pic x(28) value
'nnonono'
& 'nnnonoo'
& 'nnnoono'
& 'nnnnooo'.
03 filler redefines valid-rpn-forms.
05 rpn-form occurs 4 pic x(7).
03 current-rpn-form pic x(7).
01 calculation-area.
03 osx pic 99.
03 operator-stack pic x(32).
03 oqx pic 99.
03 oqx1 pic 99.
03 output-queue pic x(32).
03 work-number pic s9999.
03 top-numerator pic s9999 sign leading separate.
03 top-denominator pic s9999 sign leading separate.
03 rsx pic 9.
03 result-stack occurs 8.
05 numerator pic s9999.
05 denominator pic s9999.
01 error-found pic x.
01 divide-by-zero-error pic x.
*> diagnostics
01 NL pic x value x'0A'.
01 NL-flag pic x value space.
01 display-level pic x value '0'.
01 loop-lim pic 9999 value 1500.
01 loop-count pic 9999 value 0.
01 message-area value spaces.
03 message-level pic x.
03 message-value pic x(128).
*> input and examples
01 instruction pic x(32) value spaces.
01 tsx pic 99.
01 tsx-lim pic 99 value 14.
01 test-statements.
03 filler pic x(32) value '1234;1 + 2 + 3 + 4'.
03 filler pic x(32) value '1234;1 * 2 * 3 * 4'.
03 filler pic x(32) value '1234;((1)) * (((2 * 3))) * 4'.
03 filler pic x(32) value '1234;((1)) * ((2 * 3))) * 4'.
03 filler pic x(32) value '1234;(1 + 2 + 3 + 4'.
03 filler pic x(32) value '1234;)1 + 2 + 3 + 4'.
03 filler pic x(32) value '1234;1 * * 2 * 3 * 4'.
03 filler pic x(32) value '5679;6 - (5 - 7) * 9'.
03 filler pic x(32) value '1268;((1 * (8 * 6) / 2))'.
03 filler pic x(32) value '4583;-5-3+(8*4)'.
03 filler pic x(32) value '4583;8 * 4 - 5 - 3'.
03 filler pic x(32) value '4583;8 * 4 - (5 + 3)'.
03 filler pic x(32) value '1223;1 * 3 / (2 - 2)'.
03 filler pic x(32) value '2468;(6 * 8) / 4 / 2'.
01 filler redefines test-statements.
03 filler occurs 14.
05 test-numbers pic x(4).
05 filler pic x.
05 test-statement pic x(27).
procedure division.
start-twentyfour.
display 'start twentyfour'
perform generate-numbers
display 'type h <enter> to see instructions'
accept instruction
perform until instruction = spaces or 'q'
evaluate true
when instruction = 'h'
perform display-instructions
when instruction = 'n'
perform generate-numbers
when instruction(1:1) = 'm'
move instruction(2:4) to number-definitions
perform validate-number
if divide-by-zero-error = space
and 24 * top-denominator = top-numerator
display number-definitions ' is solved by ' output-queue(1:oqx)
else
display number-definitions ' is not solvable'
end-if
when instruction = 'd0' or 'd1' or 'd2' or 'd3'
move instruction(2:1) to display-level
when instruction = 'e'
display 'examples:'
perform varying tsx from 1 by 1
until tsx > tsx-lim
move spaces to statement
move test-numbers(tsx) to number-definitions
move test-statement(tsx) to statement
perform evaluate-statement
perform show-result
end-perform
when other
move instruction to statement
perform evaluate-statement
perform show-result
end-evaluate
move spaces to instruction
display 'instruction? ' with no advancing
accept instruction
end-perform
display 'exit twentyfour'
stop run
.
generate-numbers.
perform with test after until divide-by-zero-error = space
and 24 * top-denominator = top-numerator
compute n(1) = random(seconds-past-midnight) * 10 *> seed
perform varying nd from 1 by 1 until nd > 4
compute n(nd) = random() * 10
perform until n(nd) <> 0
compute n(nd) = random() * 10
end-perform
end-perform
perform validate-number
end-perform
display NL 'numbers:' with no advancing
perform varying nd from 1 by 1 until nd > 4
display space n(nd) with no advancing
end-perform
display space
.
validate-number.
perform varying p4 from 1 by 1 until p4 > p4-lim
move permutation-4(p4) to current-permutation-4
perform varying od1 from 1 by 1 until od1 > od-lim
move operator-definitions(od1:1) to current-operators(1:1)
perform varying od2 from 1 by 1 until od2 > od-lim
move operator-definitions(od2:1) to current-operators(2:1)
perform varying odx from 1 by 1 until odx > od-lim
move operator-definitions(odx:1) to current-operators(3:1)
perform varying rpx from 1 by 1 until rpx > rpx-lim
move rpn-form(rpx) to current-rpn-form
move 0 to cpx co3
move spaces to output-queue
move 7 to oqx
perform varying oqx1 from 1 by 1 until oqx1 > oqx
if current-rpn-form(oqx1:1) = 'n'
add 1 to cpx
move current-permutation-4(cpx:1) to nd
move n(nd) to output-queue(oqx1:1)
else
add 1 to co3
move current-operators(co3:1) to output-queue(oqx1:1)
end-if
end-perform
end-perform
perform evaluate-rpn
if divide-by-zero-error = space
and 24 * top-denominator = top-numerator
exit paragraph
end-if
end-perform
end-perform
end-perform
end-perform
.
display-instructions.
display '1) Type h <enter> to repeat these instructions.'
display '2) The program will display four randomly-generated'
display ' single-digit numbers and will then prompt you to enter'
display ' an arithmetic expression followed by <enter> to sum'
display ' the given numbers to 24.'
display ' The four numbers may contain duplicates and the entered'
display ' expression must reference all the generated numbers and duplicates.'
display ' Warning: the program converts the entered infix expression'
display ' to a reverse polish notation (rpn) expression'
display ' which is then interpreted from RIGHT to LEFT.'
display ' So, for instance, 8*4 - 5 - 3 will not sum to 24.'
display '3) Type n <enter> to generate a new set of four numbers.'
display ' The program will ensure the generated numbers are solvable.'
display '4) Type m#### <enter> (e.g. m1234) to create a fixed set of numbers'
display ' for testing purposes.'
display ' The program will test the solvability of the entered numbers.'
display ' For example, m1234 is solvable and m9999 is not solvable.'
display '5) Type d0, d1, d2 or d3 followed by <enter> to display none or'
display ' increasingly detailed diagnostic information as the program evaluates'
display ' the entered expression.'
display '6) Type e <enter> to see a list of example expressions and results'
display '7) Type <enter> or q <enter> to exit the program'
.
show-result.
if error-found = 'y'
or divide-by-zero-error = 'y'
exit paragraph
end-if
display 'statement in RPN is' space output-queue
evaluate true
when top-numerator = 0
when top-denominator = 0
when 24 * top-denominator <> top-numerator
display 'result (' top-numerator '/' top-denominator ') is not 24'
when other
display 'result is 24'
end-evaluate
.
evaluate-statement.
compute l-lim = length(trim(statement))
display NL 'numbers:' space n(1) space n(2) space n(3) space n(4)
move number-definitions to number-use
display 'statement is' space statement
move 1 to l
move 0 to loop-count
move space to error-found
move 0 to osx oqx
move spaces to output-queue
move 1 to p
move 1 to nt
move 0 to s
perform increment-s
perform display-start-nonterminal
perform increment-p
*>===================================
*> interpret ebnf
*>===================================
perform until s = 0
or error-found = 'y'
evaluate true
when p-symbol(p) = 'n'
and p-definition(p) = 000 *> a variable
perform test-variable
if s-result(s) = 'S'
perform increment-l
end-if
perform increment-p
when p-symbol(p) = 'n'
and p-address(p) <> p-definition(p) *> nonterminal reference
move p to s-p(s)
move p-definition(p) to p
when p-symbol(p) = 'n'
and p-address(p) = p-definition(p) *> nonterminal definition
perform increment-s
perform display-start-nonterminal
perform increment-p
when p-symbol(p) = '=' *> nonterminal control
move p to s-start-control(s)
move p-matching(p) to s-end-control(s)
perform increment-p
when p-symbol(p) = ';' *> end nonterminal
perform display-end-control
perform display-end-nonterminal
perform decrement-s
if s > 0
evaluate true
when s-result(r) = 'S'
perform set-success
when s-result(r) = 'F'
perform set-failure
end-evaluate
move s-p(s) to p
perform increment-p
perform display-continue-nonterminal
end-if
when p-symbol(p) = '{' *> start repeat sequence
perform increment-s
perform display-start-control
move p to s-start-control(s)
move p-alternate(p) to s-alternate(s)
move p-matching(p) to s-end-control(s)
move 0 to s-count(s)
perform increment-p
when p-symbol(p) = '}' *> end repeat sequence
perform display-end-control
evaluate true
when s-result(s) = 'S' *> repeat the sequence
perform display-repeat-control
perform set-nothing
add 1 to s-repeat(s)
move s-start-control(s) to p
perform increment-p
when other
perform decrement-s
evaluate true
when s-result(r) = 'N'
and s-repeat(r) = 0 *> no result
perform increment-p
when s-result(r) = 'N'
and s-repeat(r) > 0 *> no result after success
perform set-success
perform increment-p
when other *> fail the sequence
perform increment-p
end-evaluate
end-evaluate
when p-symbol(p) = '(' *> start sequence
perform increment-s
perform display-start-control
move p to s-start-control(s)
move p-alternate(p) to s-alternate(s)
move p-matching(p) to s-end-control(s)
move 0 to s-count(s)
perform increment-p
when p-symbol(p) = ')' *> end sequence
perform display-end-control
perform decrement-s
evaluate true
when s-result(r) = 'S' *> success
perform set-success
perform increment-p
when s-result(r) = 'N' *> no result
perform set-failure
perform increment-p
when other *> fail the sequence
perform set-failure
perform increment-p
end-evaluate
when p-symbol(p) = '|' *> alternate
evaluate true
when s-result(s) = 'S' *> exit the sequence
perform display-skip-alternate
move s-end-control(s) to p
when other
perform display-take-alternate
move p-alternate(p) to s-alternate(s) *> the next alternate
perform increment-p
perform set-nothing
end-evaluate
when p-symbol(p) = 't' *> terminal
move p-definition(p) to t
move terminal-symbol-len(t) to t-len
perform display-terminal
evaluate true
when statement(l:t-len) = terminal-symbol(t)(1:t-len) *> successful match
perform set-success
perform display-recognize-terminal
perform process-token
move t-len to l-len
perform increment-l
perform increment-p
when s-alternate(s) <> 000 *> we are in an alternate sequence
move s-alternate(s) to p
when other *> fail the sequence
perform set-failure
move s-end-control(s) to p
end-evaluate
when other *> end control
perform display-control-failure *> shouldnt happen
end-evaluate
end-perform
evaluate true *> at end of evaluation
when error-found = 'y'
continue
when l <= l-lim *> not all tokens parsed
display 'error: invalid statement'
perform statement-error
when number-use <> spaces
display 'error: not all numbers were used: ' number-use
move 'y' to error-found
end-evaluate
.
increment-l.
evaluate true
when l > l-lim *> end of statement
continue
when other
add l-len to l
perform varying l from l by 1
until c(l) <> space
or l > l-lim
continue
end-perform
move 1 to l-len
if l > l-lim
perform end-tokens
end-if
end-evaluate
.
increment-p.
evaluate true
when p >= p-max
display 'at' space p ' parse overflow'
space 's=<' s space s-entry(s) '>'
move 'y' to error-found
when other
add 1 to p
perform display-statement
end-evaluate
.
increment-s.
evaluate true
when s >= s-max
display 'at' space p ' stack overflow '
space 's=<' s space s-entry(s) '>'
move 'y' to error-found
when other
move s to r
add 1 to s
initialize s-entry(s)
move 'N' to s-result(s)
move p to s-p(s)
move nt to s-nt(s)
end-evaluate
.
decrement-s.
if s > 0
move s to r
subtract 1 from s
if s > 0
move s-nt(s) to nt
end-if
end-if
.
set-failure.
move 'F' to s-result(s)
if s-count(s) > 0
display 'sequential parse failure'
perform statement-error
end-if
.
set-success.
move 'S' to s-result(s)
add 1 to s-count(s)
.
set-nothing.
move 'N' to s-result(s)
move 0 to s-count(s)
.
statement-error.
display statement
move spaces to statement
move '^ syntax error' to statement(l:)
display statement
move 'y' to error-found
.
*>=====================
*> twentyfour semantics
*>=====================
test-variable.
*> check validity
perform varying nd from 1 by 1 until nd > 4
or c(l) = n(nd)
continue
end-perform
*> check usage
perform varying nu from 1 by 1 until nu > 4
or c(l) = u(nu)
continue
end-perform
evaluate true
when l > l-lim
perform set-failure
when c9(l) not numeric
perform set-failure
when nd > 4
display 'invalid number'
perform statement-error
when nu > 4
display 'number already used'
perform statement-error
when other
move space to u(nu)
perform set-success
add 1 to oqx
move c(l) to output-queue(oqx:1)
end-evaluate
.
*> ==================================
*> Dijkstra Shunting-Yard Algorithm
*> to convert infix to rpn
*> ==================================
process-token.
evaluate true
when c(l) = '('
add 1 to osx
move c(l) to operator-stack(osx:1)
when c(l) = ')'
perform varying osx from osx by -1 until osx < 1
or operator-stack(osx:1) = '('
add 1 to oqx
move operator-stack(osx:1) to output-queue(oqx:1)
end-perform
if osx < 1
display 'parenthesis error'
perform statement-error
exit paragraph
end-if
subtract 1 from osx
when (c(l) = '+' or '-') and (operator-stack(osx:1) = '*' or '/')
*> lesser operator precedence
add 1 to oqx
move operator-stack(osx:1) to output-queue(oqx:1)
move c(l) to operator-stack(osx:1)
when other
*> greater operator precedence
add 1 to osx
move c(l) to operator-stack(osx:1)
end-evaluate
.
end-tokens.
*> 1) copy stacked operators to the output-queue
perform varying osx from osx by -1 until osx < 1
or operator-stack(osx:1) = '('
add 1 to oqx
move operator-stack(osx:1) to output-queue(oqx:1)
end-perform
if osx > 0
display 'parenthesis error'
perform statement-error
exit paragraph
end-if
*> 2) evaluate the rpn statement
perform evaluate-rpn
if divide-by-zero-error = 'y'
display 'divide by zero error'
end-if
.
evaluate-rpn.
move space to divide-by-zero-error
move 0 to rsx *> stack depth
perform varying oqx1 from 1 by 1 until oqx1 > oqx
if output-queue(oqx1:1) >= '1' and <= '9'
*> push current data onto the stack
add 1 to rsx
move top-numerator to numerator(rsx)
move top-denominator to denominator(rsx)
move output-queue(oqx1:1) to top-numerator
move 1 to top-denominator
else
*> apply the operation
evaluate true
when output-queue(oqx1:1) = '+'
compute top-numerator = top-numerator * denominator(rsx)
+ top-denominator * numerator(rsx)
compute top-denominator = top-denominator * denominator(rsx)
when output-queue(oqx1:1) = '-'
compute top-numerator = top-denominator * numerator(rsx)
- top-numerator * denominator(rsx)
compute top-denominator = top-denominator * denominator(rsx)
when output-queue(oqx1:1) = '*'
compute top-numerator = top-numerator * numerator(rsx)
compute top-denominator = top-denominator * denominator(rsx)
when output-queue(oqx1:1) = '/'
compute work-number = numerator(rsx) * top-denominator
compute top-denominator = denominator(rsx) * top-numerator
if top-denominator = 0
move 'y' to divide-by-zero-error
exit paragraph
end-if
move work-number to top-numerator
end-evaluate
*> pop the stack
subtract 1 from rsx
end-if
end-perform
.
*>====================
*> diagnostic displays
*>====================
display-start-nonterminal.
perform varying nt from nt-lim by -1 until nt < 1
or p-definition(p) = nonterminal-statement-number(nt)
continue
end-perform
if nt > 0
move '1' to NL-flag
string '1' indent(1:s + s) 'at ' s space p ' start ' trim(nonterminal-statement(nt))
into message-area perform display-message
move nt to s-nt(s)
end-if
.
display-continue-nonterminal.
move s-nt(s) to nt
string '1' indent(1:s + s) 'at ' s space p space p-symbol(p) ' continue ' trim(nonterminal-statement(nt)) ' with result ' s-result(s)
into message-area perform display-message
.
display-end-nonterminal.
move s-nt(s) to nt
move '2' to NL-flag
string '1' indent(1:s + s) 'at ' s space p ' end ' trim(nonterminal-statement(nt)) ' with result ' s-result(s)
into message-area perform display-message
.
display-start-control.
string '2' indent(1:s + s) 'at ' s space p ' start ' p-symbol(p) ' in ' trim(nonterminal-statement(nt))
into message-area perform display-message
.
display-repeat-control.
string '2' indent(1:s + s) 'at ' s space p ' repeat ' p-symbol(p) ' in ' trim(nonterminal-statement(nt)) ' with result ' s-result(s)
into message-area perform display-message
.
display-end-control.
string '2' indent(1:s + s) 'at ' s space p ' end ' p-symbol(p) ' in ' trim(nonterminal-statement(nt)) ' with result ' s-result(s)
into message-area perform display-message
.
display-take-alternate.
string '2' indent(1:s + s) 'at ' s space p ' take alternate' ' in ' trim(nonterminal-statement(nt))
into message-area perform display-message
.
display-skip-alternate.
string '2' indent(1:s + s) 'at ' s space p ' skip alternate' ' in ' trim(nonterminal-statement(nt))
into message-area perform display-message
.
display-terminal.
string '1' indent(1:s + s) 'at ' s space p
' compare ' statement(l:t-len) ' to ' terminal-symbol(t)(1:t-len)
' in ' trim(nonterminal-statement(nt))
into message-area perform display-message
.
display-recognize-terminal.
string '1' indent(1:s + s) 'at ' s space p ' recognize terminal: ' c(l) ' in ' trim(nonterminal-statement(nt))
into message-area perform display-message
.
display-recognize-variable.
string '1' indent(1:s + s) 'at ' s space p ' recognize digit: ' c(l) ' in ' trim(nonterminal-statement(nt))
into message-area perform display-message
.
display-statement.
compute p1 = p - s-start-control(s)
string '3' indent(1:s + s) 'at ' s space p
' statement: ' s-start-control(s) '/' p1
space p-symbol(p) space s-result(s)
' in ' trim(nonterminal-statement(nt))
into message-area perform display-message
.
display-control-failure.
display loop-count space indent(1:s + s) 'at' space p ' control failure' ' in ' trim(nonterminal-statement(nt))
display loop-count space indent(1:s + s) ' ' 'p=<' p p-entry(p) '>'
display loop-count space indent(1:s + s) ' ' 's=<' s space s-entry(s) '>'
display loop-count space indent(1:s + s) ' ' 'l=<' l space c(l)'>'
perform statement-error
.
display-message.
if display-level = 1
move space to NL-flag
end-if
evaluate true
when loop-count > loop-lim *> loop control
display 'display count exceeds ' loop-lim
stop run
when message-level <= display-level
evaluate true
when NL-flag = '1'
display NL loop-count space trim(message-value)
when NL-flag = '2'
display loop-count space trim(message-value) NL
when other
display loop-count space trim(message-value)
end-evaluate
end-evaluate
add 1 to loop-count
move spaces to message-area
move space to NL-flag
.
end program twentyfour.
CoffeeScript
tty = require 'tty'
tty.setRawMode true
buffer = ""
numbers = []
for n in [0...4]
numbers.push Math.max 1, Math.floor(Math.random() * 9)
console.log "You can use the numbers: #{numbers.join ' '}"
process.stdin.on 'keypress', (char, key) ->
# accept operator
if char and isNaN(char) and /[()*\/+-]/.test(char) and buffer.substr(-1) isnt char
buffer += char
process.stdout.write char
# accept number
else if !isNaN(+char) and (buffer == '' or isNaN(buffer.substr -1))
buffer += char
process.stdout.write char
# check then evaluate expression
if key?.name is 'enter'
result = calculate()
process.stdout.write '\n'
if result and result is 24
console.log " = 24! congratulations."
else
console.log "#{result}. nope."
process.exit 0
# quit
if key?.name is 'escape' or (key?.name == 'c' and key.ctrl)
process.exit 0
calculate = () ->
if /[^\d\s()+*\/-]/.test buffer
console.log "invalid characters"
process.exit 1
used = buffer.match(/\d/g)
if used?.length != 4 or used.sort().join() != numbers.sort().join()
console.log "you must use the 4 numbers provided"
process.exit 1
res = try eval buffer catch e
return res or 'invalid expression'
# begin taking input
process.stdin.resume()
Commodore BASIC
This solution was taken from the ZX Spectrum example further down, however, BASIC on the Spectrum features slightly different string handling functions. Most importantly, while the val() function on the Spectrum is able to parse complete mathematical expressions within the string as it converts it to a number, Commodore BASIC will obtain only a single number provided that the first character is a valid numeric character and up to any non-numeric character. (Even floating-point numbers where 0 < n < 1 must begin with a leading 0 prior to the decimal point.)
To get around this, this program utilizes BASIC's ability to parse expressions containing simple math operators, and is in fact technically a self-modifying program. Line 2005 is a line padded with colons which simply allow BASIC to join multiple statements on a single line, otherwise perform no operation. This reserves sufficient space in memory for inserting the user's expression—by overwriting the first several bytes of colons—which can then be evaluated in the normal course of the program's execution. The subroutine at 1400 initializes a simple translation table for exchanging the operators into their proper BASIC tokens. Parenthesis, numerals, and variable names do not need to be translated.
After the user types in an expression, the program validates the input (same algorithms as the ZX Spectrum example), writes the expression as R=expression as tokenized BASIC into line 2005, and then executes the subroutine at 2000 to obtain the value. Upon return, the content of the variable R is evaluated to see if it is 24.
If the statement at line 645 is uncommented, this will allow the program to "erase" line 2005 and thus "hide" the trick. As is, if you list the program after making an attempt, you will see the last expression given to the program.
Since Commodore BASIC v2 was the initial target for this program, all other versions of Commodore BASIC are compatible as long as the base memory address for BASIC programs is adjusted. (BASIC tokens maintain compatibility across all versions.) Simply use the appropriate values for bh and bl in lines 11-15.
1 rem 24 game
2 rem for rosetta code
10 rem use appropriate basic base address
11 bh=08:bl=01: rem $0801 commodore 64
12 rem bh=16:bl=01: rem $1001 commodore +4
13 rem bh=18:bl=01: rem $1201 commodore vic-20 (35k ram)
14 rem bh=04:bl=01: rem $0401 commodore pet
15 rem bh=28:bl=01: rem $1c01 commodore 128 (bank 0)
35 print chr$(147);chr$(14);"Initializing...":gosub 1400
40 n$="":x=rnd(-ti):rem similar to 'randomize'
45 for i=1 to 4
50 t$=str$(int(rnd(1)*9)+1)
55 n$=n$+mid$(t$,2,1)
60 next i
65 print chr$(147)
70 print spc(16);"24 Game"
71 print:print " The goal of this game is to formulate"
72 print:print " an arithmetic expression that"
73 print:print " evaluates to a value of 24, however"
74 print:print " you may use only the four numbers"
75 print:print " given at random by the computer and"
76 print:print " the standard arithmetic operations of"
77 print:print " add, subtract, multiply, and divide."
78 print:print " Each digit must be used by itself. "
79 print:print " (e.g. if given 1, 2, 3, 4, you cannot"
80 print:print " combine 1 and 2 to make 12.)"
89 gosub 1000
90 i$="":f$="":p$=""
95 print chr$(147);"Allowed characters:"
100 i$=n$+"+-*/()"
110 print
120 for i=1 to len(i$)
130 print mid$(i$,i,1);" ";
140 next i:print
150 print:print "Spaces are ignored."
155 print "Enter 'end' to end.":print
160 input "Enter the formula";f$
170 if f$="end" then print "Program terminated.":end
180 print:print "Checking syntax... ";tab(34);
190 for i=1 to len(f$)
200 if mid$(f$,i,1)=" " then next i
210 c$=mid$(f$,i,1)
220 if c$="+" or c$="-" or c$="*" or c$="/" then p$=p$+"o":goto 250
230 if c$="(" or c$=")" then p$=p$+c$:goto 250
240 p$=p$+"n"
250 next i
260 restore
270 for i=1 to 11
280 read t$
290 if t$=p$ then i=11
300 next i
310 if t$<>p$ then gosub 1100:gosub 1000:goto 90
315 print "OK":print "Checking for illegal numbers... ";tab(34);
320 for i=1 to len(f$)
330 for j=1 to 10
335 ft$=mid$(f$,i,1)
336 il$=left$(i$,j-1):it$=mid$(i$,j,1):ir$=mid$(i$,j+1,len(i$))
340 if ft$=it$ and ft$>"0" and ft$<="9" then i$=il$+" "+ir$
350 next j
360 next i
370 if mid$(i$,1,4)<>" " then gosub 1200:gosub 1000:goto 90
375 print "OK":print "Evaluating expression...":print:print tab(10);f$;" =";
380 gosub 600:rem r=val(f$)
390 print r;" "
400 if r<>24 then gosub 1300:gosub 1000:goto 90
410 print "Correct!"
420 print:print "Would you like to go again (y/n)? ";
425 get k$:if k$<>"y" and k$<>"n" then 425
430 print k$
435 if k$="y" then goto 40
440 print:print "Very well. Have a nice day!"
450 end
500 rem pattern matching
501 data "nononon","(non)onon","nono(non)"
504 data "no(no(non))","((non)on)on","no(non)on"
507 data "(non)o(non)","no((non)on)","(nonon)on"
510 data "(no(non))on","no(nonon)"
600 rem get basic to evaluate our expression
605 a$="r="+f$:gosub 1440
610 for i=1 to len(a$)
615 rem simple token translation
620 b=asc(mid$(a$,i,1))
625 if (b>41 and b<48) or b=61 or b=94 then b=t(b)
630 poke (ad+i-1),b
635 next
640 gosub 2000
645 rem gosub 1440:rem uncomment to clear evaluation line after use
650 return
1000 rem screen pause
1005 pt$=" Press a key to continue. "
1010 print:print spc(20-int(len(pt$)/2));
1015 print chr$(18);pt$;chr$(146);
1020 get k$:if k$=""then 1020
1030 return
1100 rem syntax error
1105 print "ERROR":print
1110 print "Maybe something is out of place..."
1120 return
1200 rem invalid arguments
1205 print "ERROR":print
1210 print "?Invalid Arguments - "
1215 print "You used a number that is not allowed."
1220 return
1300 rem wrong formula
1305 print:print "Wrong answer. Try again."
1310 return
1400 dim t(94):t(43)=170:t(45)=171:t(42)=172:t(47)=173:t(61)=178:t(94)=174
1405 rem locate line 2005 in ram
1410 lh=bh:ll=bl:nh=0:nl=0
1415 ad=lh*256+ll
1420 lh=peek(ad+1):ll=peek(ad)
1425 nl=peek(ad+2):nh=peek(ad+3):n=nh*256+nl
1430 if n<>2005 then goto 1415
1435 ad=ad+4:return
1440 for j=ad to ad+73:poke j,asc(":"):next
1445 return
2000 rem put 74 colons on the next line
2005 ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
2010 return
- Output:
Initializing...
24 Game
The goal of this game is to formulate
an arithmetic expression that
evaluates to a value of 24, however
you may only use four numbers provided
at random by the computer and the
standard arithmetic operations of add,
subtract, multiply, and divide. Each
digit must be used by itself. (e.g. if
given 1, 2, 3, 4, you cannot combine
1 and 2 to make 12.)
Press a key to continue.
Allowed characters:
6 3 3 5 + - * / ( )
Spaces are ignored.
Enter 'end' to end.
Enter the formula? (6-3)*(3+5)
Checking syntax... OK
Checking for illegal numbers... OK
Evaluating expression...
(6-3)*(3+5) = 24
Correct!
Would you like to go again (y/n)? n
Very well. Have a nice day!
ready.
list 2005
2005 r=(6-3)*(3+5)::::::::::::::::::::::
:::::::::::::::::::::::::::::::::::::::
ready.
█
Common Lisp
(define-condition choose-digits () ())
(define-condition bad-equation (error) ())
(defun 24-game ()
(let (chosen-digits)
(labels ((prompt ()
(format t "Chosen digits: ~{~D~^, ~}~%~
Enter expression (or `bye' to quit, `!' to choose new digits): "
chosen-digits)
(read))
(lose () (error 'bad-equation))
(choose () (setf chosen-digits (loop repeat 4 collecting (1+ (random 9)))))
(check (e)
(typecase e
((eql bye) (return-from 24-game))
((eql !) (signal 'choose-digits))
(atom (lose))
(cons (check-sub (car e) (check-sub (cdr e) chosen-digits)) e)))
(check-sub (sub allowed-digits)
(typecase sub
((member nil + - * /) allowed-digits)
(integer
(if (member sub allowed-digits)
(remove sub allowed-digits :count 1)
(lose)))
(cons (check-sub (car sub) (check-sub (cdr sub) allowed-digits)))
(t (lose))))
(win ()
(format t "You win.~%")
(return-from 24-game)))
(choose)
(loop
(handler-case
(if (= 24 (eval (check (prompt)))) (win) (lose))
(error () (format t "Bad equation, try again.~%"))
(choose-digits () (choose)))))))
Verbose Implementation
(defconstant +ops+ '(* / + -))
(defun expr-numbers (e &optional acc)
"Return all the numbers in argument positions in the expression."
(cond
((numberp e) (cons e acc))
((consp e)
(append (apply #'append
(mapcar #'expr-numbers (cdr e)))
acc))))
(defun expr-well-formed-p (e)
"Return non-nil if the given expression is well-formed."
(cond
((numberp e) t)
((consp e)
(and (member (car e) +ops+)
(every #'expr-well-formed-p (cdr e))))
(t nil)))
(defun expr-valid-p (e available-digits)
"Return non-nil if the expression is well-formed and uses exactly
the digits specified."
(and (expr-well-formed-p e)
(equalp (sort (copy-seq available-digits) #'<)
(sort (expr-numbers e) #'<))))
(defun expr-get (&optional using)
(emit "Enter lisp form~@[ using the digit~P ~{~D~^ ~}~]: "
(when using
(length using)) using)
(let (*read-eval*)
(read)))
(defun digits ()
(sort (loop repeat 4 collect (1+ (random 9))) #'<))
(defun emit (fmt &rest args)
(format t "~&~?" fmt args))
(defun prompt (digits)
(emit "Using only these operators:~%~%~
~2T~{~A~^ ~}~%~%~
And exactly these numbers \(no repetition\):~%~%~
~2T~{~D~^ ~}~%~%~
~A"
+ops+ digits (secondary-prompt)))
(defun secondary-prompt ()
(fill-to 50 "Enter a lisp form which evaluates to ~
the integer 24, or \"!\" to get fresh ~
digits, or \"q\" to abort."))
(defun fill-to (n fmt &rest args)
"Poor-man's text filling mechanism."
(loop with s = (format nil "~?" fmt args)
for c across s
and i from 0
and j = 0 then (1+ j) ; since-last-newline ctr
when (char= c #\Newline)
do (setq j 0)
else when (and (not (zerop j))
(zerop (mod j n)))
do (loop for k from i below (length s)
when (char= #\Space (schar s k))
do (progn
(setf (schar s k) #\Newline
j 0)
(loop-finish)))
finally (return s)))
(defun 24-game ()
(loop with playing-p = t
and initial-digits = (digits)
for attempts from 0
and digits = initial-digits then (digits)
while playing-p
do (loop for e = (expr-get (unless (zerop attempts)
digits))
do
(case e
(! (loop-finish))
(Q (setq playing-p nil)
(loop-finish))
(R (emit "Current digits: ~S" digits))
(t
(if (expr-valid-p e digits)
(let ((v (eval e)))
(if (eql v 24)
(progn
(emit "~%~%---> A winner is you! <---~%~%")
(setq playing-p nil)
(loop-finish))
(emit "Sorry, the form you entered ~
computes to ~S, not 24.~%~%"
v)))
(emit "Sorry, the form you entered did not ~
compute.~%~%")))))
initially (prompt initial-digits)))
Example Usage:
CL-USER 97 > (24-game) Using only these operators: * / + - And exactly these numbers (no repetition): 3 7 7 9 Enter a lisp form which evaluates to the integer 24, or "!" to get fresh digits, or "q" to abort. Enter lisp form: (eval (read-from-string "(/ 1 0)")) Sorry, the form you entered did not compute. Enter lisp form: ! Enter lisp form using the digits 4 5 7 8: ! Enter lisp form using the digits 1 2 4 5: (* 4 (* 5 (- 2 1))) Sorry, the form you entered computes to 20, not 24. Enter lisp form using the digits 1 2 4 5: (* 4 (+ 5 (- 2 1))) ---> A winner is you! <--- NIL
D
import std.stdio, std.random, std.math, std.algorithm, std.range,
std.typetuple;
void main() {
void op(char c)() {
if (stack.length < 2)
throw new Exception("Wrong expression.");
stack[$ - 2] = mixin("stack[$ - 2]" ~ c ~ "stack[$ - 1]");
stack.popBack();
}
const problem = iota(4).map!(_ => uniform(1, 10))().array();
writeln("Make 24 with the digits: ", problem);
double[] stack;
int[] digits;
foreach (const char c; readln())
switch (c) {
case ' ', '\t', '\n': break;
case '1': .. case '9':
stack ~= c - '0';
digits ~= c - '0';
break;
foreach (o; TypeTuple!('+', '-', '*', '/')) {
case o: op!o(); break;
}
break;
default: throw new Exception("Wrong char: " ~ c);
}
if (!digits.sort().equal(problem.dup.sort()))
throw new Exception("Not using the given digits.");
if (stack.length != 1)
throw new Exception("Wrong expression.");
writeln("Result: ", stack[0]);
writeln(abs(stack[0] - 24) < 0.001 ? "Good job!" : "Try again.");
}
Example:
Make 24 with the digits: [1, 8, 9, 8] 8 1 - 9 + 8 + Result: 24 Good job!
Delphi
Program includes full recursive descent, expression evaluator that can handle any expression the user might eneter.
var ErrorFlag: boolean;
var ErrorStr: string;
function EvaluateExpression(Express: string): double;
{ Recursive descent expression evaluator }
var Atom: char;
var ExpressStr: string;
var ExpressInx: integer;
const Tab_Char = #$09; SP_char = #$20;
procedure HandleError(S: string);
begin
ErrorStr:=S;
ErrorFlag:=True;
Abort;
end;
procedure GetChar;
begin
if ExpressInx > Length(ExpressStr) then
begin
Atom:= ')';
end
else begin
Atom:= ExpressStr[ExpressInx];
Inc(ExpressInx);
end;
end;
procedure SkipWhiteSpace;
{ Skip Tabs And Spaces In Expression }
begin
while (Atom=TAB_Char) or (Atom=SP_char) do GetChar;
end;
procedure SkipSpaces;
{ Get Next Character, Ignoring Any Space Characters }
begin
repeat GetChar until Atom <> SP_CHAR;
end;
function GetDecimal: integer;
{ Read In A Decimal String And Return Its Value }
var S: string;
begin
Result:=0;
S:='';
while True do
begin
if not (Atom in ['0'..'9']) then break;
S:=S+Atom;
GetChar;
end;
if S='' then HandleError('Number Expected')
else Result:=StrToInt(S);
if Result>9 then HandleError('Only Numbers 0..9 allowed')
end;
function Expression: double;
{ Returns The Value Of An Expression }
function Factor: double;
{ Returns The Value Of A Factor }
var NEG: boolean;
begin
Result:=0;
while Atom='+' do SkipSpaces; { Ignore Unary "+" }
NEG:= False;
while Atom ='-' do { Unary "-" }
begin
SkipSpaces;
NEG:= not NEG;
end;
if (Atom>='0') and (Atom<='9') then Result:= GetDecimal { Unsigned Integer }
else case Atom of
'(': begin { Subexpression }
SkipSpaces;
Result:= Expression;
if Atom<>')' then HandleError('Mismatched Parenthesis');
SkipSpaces;
end;
else HandleError('Syntax Error');
end;
{ Numbers May Terminate With A Space Or Tab }
SkipWhiteSpace;
if NEG then Result:=-Result;
end; { Factor }
function Term: double;
{ Returns Factor * Factor, Etc. }
var R: double;
begin
Result:= Factor;
while True do
case Atom of
'*': begin
SkipSpaces;
Result:= Result * Factor;
end;
'/': begin
SkipSpaces;
R:=Factor;
if R=0 then HandleError('Divide By Zero');
Result:= Result / R;
end;
else break;
end;
end;
{ Term }
function AlgebraicExpression: double;
{ Returns Term + Term, Etc. }
begin
Result:= Term;
while True do
case Atom of
'+': begin SkipSpaces; Result:= Result + Term; end;
'-': begin SkipSpaces; Result:= Result - Term; end
else break;
end;
end; { Algexp }
begin { Expression }
SkipWhiteSpace;
Result:= AlgebraicExpression;
end; { Expression }
begin { EvaluateExpression }
ErrorFlag:=False;
ErrorStr:='';
ExpressStr:=Express;
ExpressInx:=1;
try
GetChar;
Result:= Expression;
except end;
end;
function WaitForString(Memo: TMemo; Prompt: string): string;
{Wait for key stroke on TMemo component}
var MW: TMemoWaiter;
var C: char;
var Y: integer;
begin
{Use custom object to wait and capture key strokes}
MW:=TMemoWaiter.Create(Memo);
try
Memo.Lines.Add(Prompt);
Memo.SelStart:=Memo.SelStart-1;
Memo.SetFocus;
Result:=MW.WaitForLine;
finally MW.Free; end;
end;
procedure Play24Game(Memo: TMemo);
{Play the 24 game}
var R: double;
var Nums: array [0..4-1] of char;
var I: integer;
var Express,RS: string;
var RB: boolean;
procedure GenerateNumbers;
{Generate and display four random number 1..9}
var S: string;
var I: integer;
begin
{Generate random numbers}
for I:=0 to High(Nums) do
Nums[I]:=char(Random(9)+$31);
{Display them}
S:='';
for I:=0 to High(Nums) do
S:=S+' '+Nums[I];
Memo.Lines.Add('Your Digits: '+S);
end;
function TestMatchingNums: boolean;
{Make sure numbers entered by user match the target numbers}
var SL1,SL2: TStringList;
var I: integer;
begin
Result:=False;
SL1:=TStringList.Create;
SL2:=TStringList.Create;
try
{Load target numbers into string list}
for I:=0 to High(Nums) do SL1.Add(Nums[I]);
{Load users expression number int string list}
for I:=1 to Length(Express) do
if Express[I] in ['0'..'9'] then SL2.Add(Express[I]);
{There should be the same number }
if SL1.Count<>SL2.Count then exit;
{Sort them to facilitate testing}
SL1.Sort; SL2.Sort;
{Are number identical, if not exit}
for I:=0 to SL1.Count-1 do
if SL1[I]<>SL2[I] then exit;
{Users numbers passed all tests}
Result:=True;
finally
SL2.Free;
SL1.Free;
end;
end;
function TestUserExpression(var S: string): boolean;
{Test expression user entered }
begin
Result:=False;
if not TestMatchingNums then
begin
S:='Numbers Do not Match';
exit;
end;
R:=EvaluateExpression(Express);
S:='Expression Value = '+FloatToStrF(R,ffFixed,18,0)+CRLF;
if ErrorFlag then
begin
S:=S+'Expression Problem: '+ErrorStr;
exit;
end;
if R<>24 then
begin
S:=S+'Expression is incorrect value';
exit;
end;
S:=S+'!!!!!! Winner !!!!!!!';
Result:=True;
end;
begin
Randomize;
Memo.Lines.Add('=========== 24 Game ===========');
GenerateNumbers;
while true do
begin
if Application.Terminated then exit;
Express:=WaitForString(Memo,'Enter expression, Q = quit, N = New numbers: '+CRLF);
if Pos('N',UpperCase(Express))>0 then
begin
GenerateNumbers;
Continue;
end;
if Pos('Q',UpperCase(Express))>0 then exit;
RB:=TestUserExpression(RS);
Memo.Lines.Add(RS);
if not RB then continue;
RS:=WaitForString(Memo,'Play again Y=Yes, N=No'+CRLF);
if Pos('N',UpperCase(RS))>0 then exit;
GenerateNumbers;
end;
end;
- Output:
=========== 24 Game =========== Your Digits: 8 2 5 5 Enter expression, Q = quit, N = New numbers: n Your Digits: 3 1 9 3 Enter expression, Q = quit, N = New numbers: 3 * 9 -3 Numbers Do not Match Enter expression, Q = quit, N = New numbers: 3 * 9 - 3 * 1 Expression Value = 24 !!!!!! Winner !!!!!!! Play again Y=Yes, N=No
EchoLisp
(string-delimiter "")
;; check that nums are in expr, and only once
(define (is-valid? expr sorted: nums)
(when (equal? 'q expr) (error "24-game" "Thx for playing"))
(unless (and
(list? expr)
(equal? nums (list-sort < (filter number? (flatten expr)))))
(writeln "🎃 Please use" nums)
#f))
;; 4 random digits
(define (gen24)
(->> (append (range 1 10)(range 1 10)) shuffle (take 4) (list-sort < )))
(define (is-24? num)
(unless (= 24 num)
(writeln "😧 Sorry - Result = " num)
#f))
(define (check-24 expr)
(if (and
(is-valid? expr nums)
(is-24? (js-eval (string expr)))) ;; use js evaluator
"🍀 🌸 Congrats - (play24) for another one."
(input-expr check-24 (string nums))))
(define nums null)
(define (play24)
(set! nums (gen24))
(writeln "24-game - Can you combine" nums "to get 24 ❓ (q to exit)")
(input-expr check-24 (string-append (string nums) " -> 24 ❓")))
- Output:
24-game - Can you combine (2 5 6 7) to get 24 ❓ (q to exit)
difficult game
🎃 Please use (2 5 6 7)
12 * 2
🎃 Please use (2 5 6 7)
6 * (7 - 5 + 2)
🍀 🌸 Congrats - (play24) for another one.
(play24)
24-game - Can you combine (3 5 8 9) to get 24 ❓ (q to exit)
3 + 5 + 8 * 9
😧 Sorry - Result = 80
9 * 3 - (8 - 5)
🍀 🌸 Congrats - (play24) for another one.
(play24)
24-game - Can you combine (1 8 8 9) to get 24 ❓ (q to exit)
9 + 8 + 8 - 1
🍀 🌸 Congrats - (play24) for another one.
Elena
ELENA 6.0 :
import system'routines;
import system'collections;
import system'dynamic;
import extensions;
// --- Expression ---
class ExpressionTree
{
object _tree;
constructor(s)
{
auto level := new Integer(0);
s.forEach::(ch)
{
var node := new DynamicStruct();
ch =>
$43 { node.Level := level + 1; node.Operation := mssg add } // +
$45 { node.Level := level + 1; node.Operation := mssg subtract } // -
$42 { node.Level := level + 2; node.Operation := mssg multiply } // *
$47 { node.Level := level + 2; node.Operation := mssg divide } // /
$40 { level.append(10); ^ self } // (
$41 { level.reduce(10); ^ self } // )
! {
node.Leaf := ch.toString().toReal();
node.Level := level + 3
};
if (nil == _tree)
{
_tree := node
}
else
{
if (_tree.Level >= node.Level)
{
node.Left := _tree;
node.Right := nil;
_tree := node
}
else
{
var top := _tree;
while ((nil != top.Right)&&(top.Right.Level < node.Level))
{ top := top.Right };
node.Left := top.Right;
node.Right := nil;
top.Right := node
}
}
}
}
eval(node)
{
if (node.containsProperty(mssg Leaf))
{
^ node.Leaf
}
else
{
var left := self.eval(node.Left);
var right := self.eval(node.Right);
var op := node.Operation;
^ op(left, right);
}
}
get Value()
<= eval(_tree);
readLeaves(list, node)
{
if (nil == node)
{ InvalidArgumentException.raise() };
if (node.containsProperty(mssg Leaf))
{
list.append(node.Leaf)
}
else
{
self.readLeaves(list, node.Left);
self.readLeaves(list, node.Right)
}
}
readLeaves(list)
<= readLeaves(list,_tree);
}
// --- Game ---
class TwentyFourGame
{
object theNumbers;
constructor()
{
self.newPuzzle();
}
newPuzzle()
{
theNumbers := new object[]
{
1 + randomGenerator.nextInt(9),
1 + randomGenerator.nextInt(9),
1 + randomGenerator.nextInt(9),
1 + randomGenerator.nextInt(9)
}
}
help()
{
console
.printLine("------------------------------- Instructions ------------------------------")
.printLine("Four digits will be displayed.")
.printLine("Enter an equation using all of those four digits that evaluates to 24")
.printLine("Only * / + - operators and () are allowed")
.printLine("Digits can only be used once, but in any order you need.")
.printLine("Digits cannot be combined - i.e.: 12 + 12 when given 1,2,2,1 is not allowed")
.printLine("Submit a blank line to skip the current puzzle.")
.printLine("Type 'q' to quit")
.writeLine()
.printLine("Example: given 2 3 8 2, answer should resemble 8*3-(2-2)")
.printLine("------------------------------- --------------------------------------------")
}
prompt()
{
theNumbers.forEach::(n){ console.print(n," ") };
console.print(": ")
}
resolve(expr)
{
var tree := new ExpressionTree(expr);
var leaves := new ArrayList();
tree.readLeaves(leaves);
ifnot (leaves.ascendant().sequenceEqual(theNumbers.ascendant()))
{ console.printLine("Invalid input. Enter an equation using all of those four digits. Try again."); ^ self };
var result := tree.Value;
if (result == 24)
{
console.printLine("Good work. ",expr,"=",result);
self.newPuzzle()
}
else
{
console.printLine("Incorrect. ",expr,"=",result)
}
}
}
extension gameOp
{
playRound(expr)
{
if (expr == "q")
{
^ false
}
else
{
if (expr == "")
{
console.printLine("Skipping this puzzle"); self.newPuzzle()
}
else
{
try
{
self.resolve(expr)
}
catch(Exception e)
{
console.printLine(e)
//console.printLine:"An error occurred. Check your input and try again."
}
};
^ true
}
}
}
// --- program ---
public program()
{
var game := new TwentyFourGame().help();
while (game.prompt().playRound(console.readLine())) {}
}- Output:
------------------------------- Instructions ------------------------------ Four digits will be displayed. Enter an equation using all of those four digits that evaluates to 24 Only * / + - operators and () are allowed Digits can only be used once, but in any order you need. Digits cannot be combined - i.e.: 12 + 12 when given 1,2,2,1 is not allowed Submit a blank line to skip the current puzzle. Type 'q' to quit Example: given 2 3 8 2, answer should resemble 8*3-(2-2) ------------------------------- -------------------------------------------- 7 6 9 6 : Skipping this puzzle 8 6 2 6 : 6*6-8-2 Incorrect. 6*6-8-2=26.0 8 6 2 6 : Skipping this puzzle 5 2 7 7 : 7+7+(5*2) Good work. 7+7+(5*2)=24.0
Elixir
defmodule Game24 do
def main do
IO.puts "24 Game"
play
end
defp play do
IO.puts "Generating 4 digits..."
digts = for _ <- 1..4, do: Enum.random(1..9)
IO.puts "Your digits\t#{inspect digts, char_lists: :as_lists}"
read_eval(digts)
play
end
defp read_eval(digits) do
exp = IO.gets("Your expression: ") |> String.strip
if exp in ["","q"], do: exit(:normal) # give up
case {correct_nums(exp, digits), eval(exp)} do
{:ok, x} when x==24 -> IO.puts "You Win!"
{:ok, x} -> IO.puts "You Lose with #{inspect x}!"
{err, _} -> IO.puts "The following numbers are wrong: #{inspect err, char_lists: :as_lists}"
end
end
defp correct_nums(exp, digits) do
nums = String.replace(exp, ~r/\D/, " ") |> String.split |> Enum.map(&String.to_integer &1)
if length(nums)==4 and (nums--digits)==[], do: :ok, else: nums
end
defp eval(exp) do
try do
Code.eval_string(exp) |> elem(0)
rescue
e -> Exception.message(e)
end
end
end
Game24.main
- Output:
24 Game Generating 4 digits... Your digits [9, 6, 7, 4] Your expression: (9+7)*6/4 You Win! Generating 4 digits... Your digits [3, 2, 2, 4] Your expression: 3*(2+2+4) You Win!
Erlang
-module(g24).
-export([main/0]).
main() ->
random:seed(now()),
io:format("24 Game~n"),
play().
play() ->
io:format("Generating 4 digits...~n"),
Digts = [random:uniform(X) || X <- [9,9,9,9]],
io:format("Your digits\t~w~n", [Digts]),
read_eval(Digts),
play().
read_eval(Digits) ->
Exp = string:strip(io:get_line(standard_io, "Your expression: "), both, $\n),
case {correct_nums(Exp, Digits), eval(Exp)} of
{ok, X} when X == 24 -> io:format("You Win!~n");
{ok, X} -> io:format("You Lose with ~p!~n",[X]);
{List, _} -> io:format("The following numbers are wrong: ~p~n", [List])
end.
correct_nums(Exp, Digits) ->
case re:run(Exp, "([0-9]+)", [global, {capture, all_but_first, list}]) of
nomatch ->
"No number entered";
{match, IntLs} ->
case [X || [X] <- IntLs, not lists:member(list_to_integer(X), Digits)] of
[] -> ok;
L -> L
end
end.
eval(Exp) ->
{X, _} = eval(re:replace(Exp, "\\s", "", [{return, list},global]),
0),
X.
eval([], Val) ->
{Val,[]};
eval([$(|Rest], Val) ->
{NewVal, Exp} = eval(Rest, Val),
eval(Exp, NewVal);
eval([$)|Rest], Val) ->
{Val, Rest};
eval([$[|Rest], Val) ->
{NewVal, Exp} = eval(Rest, Val),
eval(Exp, NewVal);
eval([$]|Rest], Val) ->
{Val, Rest};
eval([$+|Rest], Val) ->
{NewOperand, Exp} = eval(Rest, 0),
eval(Exp, Val + NewOperand);
eval([$-|Rest], Val) ->
{NewOperand, Exp} = eval(Rest, 0),
eval(Exp, Val - NewOperand);
eval([$*|Rest], Val) ->
{NewOperand, Exp} = eval(Rest, 0),
eval(Exp, Val * NewOperand);
eval([$/|Rest], Val) ->
{NewOperand, Exp} = eval(Rest, 0),
eval(Exp, Val / NewOperand);
eval([X|Rest], 0) when X >= $1, X =< $9 ->
eval(Rest, X-$0).
The evaluator uses a simple infix scheme that doesn't care about operator precedence, but does support brackets and parentheses alike. Thus, ((9+1)*2)+2+2 is evaluated as:
9 + 1 = 10 10 * 2 = 20 2 + 2 = 4 20 + 4
Example:
1> c(g24).
{ok,g24}
2> g24:main().
24 Game
Generating 4 digits...
Your digits [7,4,6,8]
Your expression: 6*4
You Win!
Generating 4 digits...
Your digits [4,1,5,8]
Your expression: 6*4
The following numbers are wrong: ["6"]
Generating 4 digits...
Your digits [8,5,8,2]
Your expression: 2*([8/5]*2)
You Lose with 6.4!
Generating 4 digits...
Your digits [7,4,8,1]
F#
open System
open System.Text.RegularExpressions
// Some utilities
let (|Parse|_|) regex str =
let m = Regex(regex).Match(str)
if m.Success then Some ([for g in m.Groups -> g.Value]) else None
let rec gcd x y = if x = y || x = 0 then y else if x < y then gcd y x else gcd y (x-y)
let abs (x : int) = Math.Abs x
let sign (x: int) = Math.Sign x
let cint s = Int32.Parse(s)
let replace m (s : string) t = Regex.Replace(t, m, s)
// computing in Rationals
type Rat(x : int, y : int) =
let g = if y <> 0 then gcd (abs x) (abs y) else raise <| DivideByZeroException()
member this.n = sign y * x / g // store a minus sign in the numerator
member this.d =
if y <> 0 then sign y * y / g else raise <| DivideByZeroException()
static member (~-) (x : Rat) = Rat(-x.n, x.d)
static member (+) (x : Rat, y : Rat) = Rat(x.n * y.d + y.n * x.d, x.d * y.d)
static member (-) (x : Rat, y : Rat) = x + Rat(-y.n, y.d)
static member (*) (x : Rat, y : Rat) = Rat(x.n * y.n, x.d * y.d)
static member (/) (x : Rat, y : Rat) = x * Rat(y.d, y.n)
override this.ToString() = sprintf @"<%d,%d>" this.n this.d
new(x : string, y : string) = if y = "" then Rat(cint x, 1) else Rat(cint x, cint y)
// Due to the constraints imposed by the game (reduced set
// of operators, all left associativ) we can get away with a repeated reduction
// to evaluate the algebraic expression.
let rec reduce (str :string) =
let eval (x : Rat) (y : Rat) = function
| "*" -> x * y | "/" -> x / y | "+" -> x + y | "-" -> x - y | _ -> failwith "unknown op"
let subst s r = str.Replace(s, r.ToString())
let rstr =
match str with
| Parse @"\(<(-?\d+),(\d+)>([*/+-])<(-?\d+),(\d+)>\)" [matched; xn; xd; op; yn; yd] ->
subst matched <| eval (Rat(xn,xd)) (Rat(yn,yd)) op
| Parse @"<(-?\d+),(\d+)>([*/])<(-?\d+),(\d+)>" [matched; xn; xd; op; yn; yd] ->
subst matched <| eval (Rat(xn,xd)) (Rat(yn,yd)) op
| Parse @"<(-?\d+),(\d+)>([+-])<(-?\d+),(\d+)>" [matched; xn; xd; op; yn; yd] ->
subst matched <| eval (Rat(xn,xd)) (Rat(yn,yd)) op
| Parse @"\(<(-?\d+),(\d+)>\)" [matched; xn; xd] ->
subst matched <| Rat(xn,xd)
| Parse @"(?<!>)-<(-?\d+),(\d+)>" [matched; xn; xd] ->
subst matched <| -Rat(xn,xd)
| _ -> str
if str = rstr then str else reduce rstr
let gameLoop() =
let checkInput dddd input =
match input with
| "n" | "q" -> Some(input)
| Parse @"[^1-9()*/+-]" [c] ->
printfn "You used an illegal character in your expression: %s" c
None
| Parse @"^\D*(\d)\D+(\d)\D+(\d)\D+(\d)(?:\D*(\d))*\D*$" [m; d1; d2; d3; d4; d5] ->
if d5 = "" && (String.Join(" ", Array.sort [|d1;d2;d3;d4|])) = dddd then Some(input)
elif d5 = "" then
printfn "Use this 4 digits with operators in between: %s." dddd
None
else
printfn "Use only this 4 digits with operators in between: %s." dddd
None
| _ ->
printfn "Use all 4 digits with operators in between: %s." dddd
None
let rec userLoop dddd =
let tryAgain msg =
printfn "%s" msg
userLoop dddd
printf "[Expr|n|q]: "
match Console.ReadLine() |> replace @"\s" "" |> checkInput dddd with
| Some(input) ->
let data = input |> replace @"((?<!\d)-)?\d+" @"<$&,1>"
match data with
| "n" -> true | "q" -> false
| _ ->
try
match reduce data with
| Parse @"^<(-?\d+),(\d+)>$" [_; x; y] ->
let n, d = (cint x), (cint y)
if n = 24 then
printfn "Correct!"
true
elif d=1 then tryAgain <| sprintf "Wrong! Value = %d." n
else tryAgain <| sprintf "Wrong! Value = %d/%d." n d
| _ -> tryAgain "Wrong! not a well-formed expression!"
with
| :? System.DivideByZeroException ->
tryAgain "Wrong! Your expression results in a division by zero!"
| ex ->
tryAgain <| sprintf "There is an unforeseen problem with yout input: %s" ex.Message
| None -> userLoop dddd
let random = new Random(DateTime.Now.Millisecond)
let rec loop() =
let dddd = String.Join(" ", Array.init 4 (fun _ -> 1 + random.Next 9) |> Array.sort)
printfn "\nCompute 24 from the following 4 numbers: %s" dddd
printfn "Use them in any order with * / + - and parentheses; n = new numbers; q = quit"
if userLoop dddd then loop()
loop()
gameLoop()
- Output:
Compute 24 from the following 4 numbers: 3 3 3 5 Use them in any order with * / + - and parentheses; n = new numbers; q = quit [Expr|n|q]: n Compute 24 from the following 4 numbers: 3 5 6 7 Use them in any order with * / + - and parentheses; n = new numbers; q = quit [Expr|n|q]: (7 + 5) + 6/3 Wrong! Value = 14. [Expr|n|q]: (7 + 5) * 6/3 Correct! Compute 24 from the following 4 numbers: 3 3 4 5 Use them in any order with * / + - and parentheses; n = new numbers; q = quit [Expr|n|q]: q
Factor
USING:
combinators.short-circuit
continuations
eval
formatting
fry
kernel
io
math math.ranges
prettyprint
random
sequences
sets ;
IN: 24game
: choose4 ( -- seq )
4 [ 9 [1,b] random ] replicate ;
: step ( numbers -- ? )
readln
[
parse-string
{
! Is only allowed tokens used?
[ swap { + - / * } append subset? ]
! Digit count in expression should be equal to the given numbers.
[ [ number? ] count swap length = ]
! Of course it must evaluate to 24
[ nip call( -- x ) 24 = ]
} 2&&
[ f "You got it!" ]
[ t "Expression isnt valid, or doesnt evaluate to 24." ]
if
]
[ 3drop f "Could not parse that." ]
recover print flush ;
: main ( -- )
choose4
[ "Your numbers are %[%s, %], make an expression\n" printf flush ]
[ '[ _ step ] loop ]
bi ;
Sample:
IN: scratchpad main
Your numbers are { 4, 1, 8, 2 }, make an expression
8 4 + 2 * 1 /
You got it!
Falcon
load compiler
function genRandomNumbers( amount )
rtn = []
for i in [ 0 : amount ]: rtn += random( 1, 9 )
return( rtn )
end
function getAnswer( exp )
ic = ICompiler()
ic.compileAll(exp)
return( ic.result )
end
function validInput( str )
for i in [ 0 : str.len() ]
if str[i] notin ' ()[]0123456789-+/*'
> 'INVALID Character = ', str[i]
return( false )
end
end
return( true )
end
printl('
The 24 Game
Given any four digits in the range 1 to 9, which may have repetitions,
Using just the +, -, *, and / operators; and the possible use of
brackets, (), show how to make an answer of 24.
An answer of "q" will quit the game.
An answer of "!" will generate a new set of four digits.
Otherwise you are repeatedly asked for an expression until it evaluates to 24
Note: you cannot form multiple digit numbers from the supplied digits,
so an answer of 12+12 when given 1, 2, 2, and 1 would not be allowed.
')
num = genRandomNumbers( 4 )
while( true )
>> "Here are the numbers to choose from: "
map({ a => print(a, " ") }, num)
>
exp = input()
switch exp
case "q", "Q"
exit()
case "!"
> 'Generating new numbers list'
num = genRandomNumbers( 4 )
default
if not validInput( exp ): continue
answer = getAnswer( exp )
if answer == 24
> "By George you GOT IT! Your expression equals 24"
else
> "Ahh Sorry, So Sorry your answer of ", answer, " does not equal 24."
end
end
endFortran
Clever implementation
Indicate operator precedence by parentheses; e.g. (3+(5*6))-9. No whitespace is admissible. The program uses Insertion_sort in Fortran.
program game_24
implicit none
real :: vector(4), reals(11), result, a, b, c, d
integer :: numbers(4), ascii(11), i
character(len=11) :: expression
character :: syntax(11)
! patterns:
character, parameter :: one(11) = (/ '(','(','1','x','1',')','x','1',')','x','1' /)
character, parameter :: two(11) = (/ '(','1','x','(','1','x','1',')',')','x','1' /)
character, parameter :: three(11) = (/ '1','x','(','(','1','x','1',')','x','1',')' /)
character, parameter :: four(11) = (/ '1','x','(','1','x','(','1','x','1',')',')' /)
character, parameter :: five(11) = (/ '(','1','x','1',')','x','(','1','x','1',')' /)
do
call random_number(vector)
numbers = 9 * vector + 1
write (*,*) 'Digits: ',numbers
write (*,'(a)',advance='no') 'Your expression: '
read (*,'(a11)') expression
forall (i=1:11) syntax(i) = expression(i:i)
ascii = iachar(syntax)
where (syntax >= '0' .and. syntax <= '9')
syntax = '1' ! number
elsewhere (syntax == '+' .or. syntax == '-' .or. syntax == '*' .or. syntax == '/')
syntax = 'x' ! op
elsewhere (syntax /= '(' .and. syntax /= ')')
syntax = '-' ! error
end where
reals = real(ascii-48)
if ( all(syntax == one) ) then
a = reals(3); b = reals(5); c = reals(8); d = reals(11)
call check_numbers(a,b,c,d)
result = op(op(op(a,4,b),7,c),10,d)
else if ( all(syntax == two) ) then
a = reals(2); b = reals(5); c = reals(7); d = reals(11)
call check_numbers(a,b,c,d)
result = op(op(a,3,op(b,6,c)),10,d)
else if ( all(syntax == three) ) then
a = reals(1); b = reals(5); c = reals(7); d = reals(10)
call check_numbers(a,b,c,d)
result = op(a,2,op(op(b,6,c),9,d))
else if ( all(syntax == four) ) then
a = reals(1); b = reals(4); c = reals(7); d = reals(9)
call check_numbers(a,b,c,d)
result = op(a,2,op(b,5,op(c,8,d)))
else if ( all(syntax == five) ) then
a = reals(2); b = reals(4); c = reals(8); d = reals(10)
call check_numbers(a,b,c,d)
result = op(op(a,3,b),6,op(c,9,d))
else
stop 'Input string: incorrect syntax.'
end if
if ( abs(result-24.0) < epsilon(1.0) ) then
write (*,*) 'You won!'
else
write (*,*) 'Your result (',result,') is incorrect!'
end if
write (*,'(a)',advance='no') 'Another one? [y/n] '
read (*,'(a1)') expression
if ( expression(1:1) == 'n' .or. expression(1:1) == 'N' ) then
stop
end if
end do
contains
pure real function op(x,c,y)
integer, intent(in) :: c
real, intent(in) :: x,y
select case ( char(ascii(c)) )
case ('+')
op = x+y
case ('-')
op = x-y
case ('*')
op = x*y
case ('/')
op = x/y
end select
end function op
subroutine check_numbers(a,b,c,d)
real, intent(in) :: a,b,c,d
integer :: test(4)
test = (/ nint(a),nint(b),nint(c),nint(d) /)
call Insertion_Sort(numbers)
call Insertion_Sort(test)
if ( any(test /= numbers) ) then
stop 'You cheat ;-) (Incorrect numbers)'
end if
end subroutine check_numbers
pure subroutine Insertion_Sort(a)
integer, intent(inout) :: a(:)
integer :: temp, i, j
do i=2,size(a)
j = i-1
temp = a(i)
do while ( j>=1 .and. a(j)>temp )
a(j+1) = a(j)
j = j - 1
end do
a(j+1) = temp
end do
end subroutine Insertion_Sort
end program game_24
As a more general recursive descent parser:
Permits spaces and arbitrary parentheses.
! implement a recursive descent parser
module evaluate_algebraic_expression
integer, parameter :: size = 124
character, parameter :: statement_end = achar(0)
character(len=size) :: text_to_parse
integer :: position
data position/0/,text_to_parse/' '/
contains
character function get_token()
! return the current token
implicit none
if (position <= size) then
get_token = text_to_parse(position:position)
do while (get_token <= ' ')
call advance
if (size < position) exit
get_token = text_to_parse(position:position)
end do
end if
if (size < position) get_token = statement_end
end function get_token
subroutine advance ! consume a token. Move to the next token. consume_token would have been a better name.
position = position + 1
end subroutine advance
logical function unfinished()
unfinished = get_token() /= statement_end
end function unfinished
subroutine parse_error()
write(6,*)'"'//get_token()//'" unexpected in expression at',position
stop 1
end subroutine parse_error
function precedence3() result(a)
implicit none
real :: a
character :: token
character(len=10), parameter :: digits = '0123456789'
token = get_token()
if (verify(token,digits) /= 0) call parse_error()
a = index(digits, token) - 1
call advance()
end function precedence3
recursive function precedence2() result(a)
real :: a
character :: token
token = get_token()
if (token /= '(') then
a = precedence3()
else
call advance
a = precedence0()
token = get_token()
if (token /= ')') call parse_error()
call advance
end if
end function precedence2
recursive function precedence1() result(a)
implicit none
real :: a
real, dimension(2) :: argument
character(len=2), parameter :: tokens = '*/'
character :: token
a = 0
token = get_token()
argument(1) = precedence2()
token = get_token()
do while (verify(token,tokens) == 0)
call advance()
argument(2) = precedence2()
if (token == '/') argument(2) = 1 / argument(2)
argument(1) = product(argument)
token = get_token()
end do
a = argument(1)
end function precedence1
recursive function precedence0() result(a)
implicit none
real :: a
real, dimension(2) :: argument
character(len=2), parameter :: tokens = '+-'
character :: token
a = 0
token = get_token()
argument(1) = precedence1()
token = get_token()
do while (verify(token,tokens) == 0)
call advance()
argument(2) = precedence1()
if (token == '-') argument = argument * (/1, -1/)
argument(1) = sum(argument)
token = get_token()
end do
a = argument(1)
end function precedence0
real function statement()
implicit none
if (unfinished()) then
statement = precedence0()
else !empty okay
statement = 0
end if
if (unfinished()) call parse_error()
end function statement
real function evaluate(expression)
implicit none
character(len=*), intent(in) :: expression
text_to_parse = expression
evaluate = statement()
end function evaluate
end module evaluate_algebraic_expression
program g24
use evaluate_algebraic_expression
implicit none
integer, dimension(4) :: digits
character(len=78) :: expression
real :: result
! integer :: i
call random_seed!easily found internet examples exist to seed by /dev/urandom or time
call deal(digits)
! do i=1, 9999 ! produce the data to test digit distribution
! call deal(digits)
! write(6,*) digits
! end do
write(6,'(a13,4i2,a26)')'Using digits',digits,', and the algebraic dyadic'
write(6,*)'operators +-*/() enter an expression computing 24.'
expression = ' '
read(5,'(a78)') expression
if (invalid_digits(expression, digits)) then
write(6,*)'invalid digits'
else
result = evaluate(expression)
if (nint(result) == 24) then
write(6,*) result, ' close enough'
else
write(6,*) result, ' no good'
end if
end if
contains
logical function invalid_digits(e,d) !verify the digits
implicit none
character(len=*), intent(in) :: e
integer, dimension(4), intent(inout) :: d
integer :: i, j, k, count
logical :: unfound
count = 0
invalid_digits = .false. !validity assumed
!write(6,*)'expression:',e(1:len_trim(e))
do i=1, len_trim(e)
if (verify(e(i:i),'0123456789') == 0) then
j = index('0123456789',e(i:i))-1
unfound = .true.
do k=1, 4
if (j == d(k)) then
unfound = .false.
exit
end if
end do
if (unfound) then
invalid_digits = .true.
!return or exit is okay here
else
d(k) = -99
count = count + 1
end if
end if
end do
invalid_digits = invalid_digits .or. (count /= 4)
end function invalid_digits
subroutine deal(digits)
implicit none
integer, dimension(4), intent(out) :: digits
integer :: i
real :: harvest
call random_number(harvest)
do i=1, 4
digits(i) = int(mod(harvest*9**i, 9.0)) + 1
end do
! NB. computed with executable Iverson notation, www.jsoftware.oom
! #B NB. B are the digits from 9999 deals
! 39996
! ({.,#)/.~/:~B # show the distribution of digits
! 0 4380
! 1 4542
! 2 4348
! 3 4395
! 4 4451
! 5 4474
! 6 4467
! 7 4413
! 8 4526
! NB. this also shows that I forgot to add 1. Inserting now...
end subroutine deal
end program g24
Compilation and too many examples. Which would you cut?
$ gfortran -g -O0 -std=f2008 -Wall f.f08 -o f.exe && echo '8*(9/9+2)' | ./f.exe Using digits 9 9 8 2, and the algebraic dyadic operators +-*/() enter an expression computing 24. 24.000000 close enough $ $ $ $ ./f.exe $ Using digits 9 9 8 2, and the algebraic dyadic $ operators +-*/() enter an expression computing 24. $ 8 * ( 9 / 9 + 2 ) $ 24.000000 close enough $ $ $ ./f.exe Using digits 9 9 8 2, and the algebraic dyadic operators +-*/() enter an expression computing 24. (((2+8+9+9))) 28.000000 no good $ $ $ ./f.exe Using digits 9 9 8 2, and the algebraic dyadic operators +-*/() enter an expression computing 24. (((8+9-2+9))) 24.000000 close enough $ $ ./f.exe Using digits 9 9 8 2, and the algebraic dyadic operators +-*/() enter an expression computing 24. 8929 "9" unexpected in expression at 2 STOP 1 $ $ $ ./f.exe Using digits 9 9 8 2, and the algebraic dyadic operators +-*/() enter an expression computing 24. 12348 invalid digits $ $ $ ./f.exe Using digits 9 9 8 2, and the algebraic dyadic operators +-*/() enter an expression computing 24. 892 invalid digits $ $ $ ./f.exe Using digits 9 9 8 2, and the algebraic dyadic operators +-*/() enter an expression computing 24. 8921 invalid digits $ $ $ $ ./f.exe Using digits 9 9 8 2, and the algebraic dyadic operators +-*/() enter an expression computing 24. 89291 invalid digits $ $ $ $ ./f.exe Using digits 9 9 8 2, and the algebraic dyadic operators +-*/() enter an expression computing 24. 9+x-2+8+9 "x" unexpected in expression at 3 STOP 1 $ $ $ $ ./f.exe Using digits 9 9 8 2, and the algebraic dyadic operators +-*/() enter an expression computing 24. (9-2)+8+(9 "^@" unexpected in expression at 125 STOP 1 $ $ $ $ ./f.exe Using digits 9 9 8 2, and the algebraic dyadic operators +-*/() enter an expression computing 24. (9-2)+8+(9) 24.000000 close enough $ $ $ $ ./f.exe Using digits 9 9 8 2, and the algebraic dyadic operators +-*/() enter an expression computing 24. (9-2)+8/(9) 7.8888888 no good $
FreeBASIC
Solución en RPN:
' The 24 game en FreeBASIC
Const operaciones = "*/+-"
Declare Sub Encabezado
Declare Function escoge4() As String
Declare Function quitaEspacios(cadena As String, subcadena1 As String, subcadena2 As String) As String
Declare Function evaluaEntrada(cadena As String) As Integer
Declare Function evaluador(oper1 As Byte, oper2 As Byte, operacion As String) As Integer
Dim Shared As String serie, entrada, cadena
Dim As Integer resultado
Sub Encabezado
Cls: Color 15
Print "The 24 Game"
Print "============" + Chr(13) + Chr(10)
Print "Dados cuatro dígitos en el rango de 1 a 9, que pueden repetirse, "
Print "usando solo los operadores aritméticos suma (+), resta (-), "
Print "multiplicación (*) y división (/) intentar obtener un resultado de 24." + Chr(13) + Chr(10)
Print "Use la notación polaca inversa (primero los operandos y luego los operadores)."
Print "Por ejemplo: en lugar de 2 + 4, escriba 2 4 +" + Chr(13) + Chr(10)
End Sub
Function escoge4() As String
Dim As Byte i
Dim As String a, b
Print "Los dígitos a utilizar son: ";
For i = 1 To 4
a = Str(Int(Rnd*9)+1)
Print a;" ";
b = b + a
Next i
escoge4 = b
End Function
Function evaluaEntrada(cadena As String) As Integer
Dim As Byte oper1, oper2, n(4), i
Dim As String op
oper1 = 0: oper2 = 0: i = 0
While cadena <> ""
op = Left(cadena, 1)
entrada = Mid(cadena, 2)
If Instr(serie, op) Then
i = i + 1
n(i) = Val(op)
Elseif Instr(operaciones, op) Then
oper2 = n(i)
n(i) = 0
i = i - 1
oper1 = n(i)
n(i) = evaluador(oper1, oper2, op)
Else
Print "Signo no v lido"
End If
Wend
evaluaEntrada = n(i)
End Function
Function evaluador(oper1 As Byte, oper2 As Byte, operacion As String) As Integer
Dim As Integer t
Select Case operacion
Case "+": t = oper1 + oper2
Case "-": t = oper1 - oper2
Case "*": t = oper1 * oper2
Case "/": t = oper1 / oper2
End Select
evaluador = t
End Function
Function quitaEspacios(cadena As String, subcadena1 As String, subcadena2 As String) As String
Dim As Byte len1 = Len(subcadena1), len2 = Len(subcadena2)
Dim As Byte i
i = Instr(cadena, subcadena1)
While i
cadena = Left(cadena, i - 1) & subcadena2 & Mid(cadena, i + len1)
i = Instr(i + len2, cadena, subcadena1)
Wend
quitaEspacios = cadena
End Function
'--- Programa Principal ---
Randomize Timer
Do
Encabezado
serie = escoge4
Print: Line Input "Introduzca su fórmula en notación polaca inversa: ", entrada
entrada = quitaEspacios(entrada, " ", "")
If (Len(entrada) <> 7) Then
Print "Error en la serie introducida."
Else
resultado = evaluaEntrada(entrada)
Print "El resultado es = "; resultado
If resultado = 24 Then
Print "¡Correcto!"
Else
Print "¡Error!"
End If
End If
Print "¿Otra ronda? (Pulsa S para salir, u otra tecla para continuar)"
Loop Until (Ucase(Input(1)) = "S")
End
'--------------------------
- Output:
The 24 Game ============ Dados cuatro dígitos en el rango de 1 a 9, que pueden repetirse, usando solo los operadores aritmÚticos suma (+), resta (-), multiplicación (*) y división (/) intentar obtener un resultado de 24. Use la notación polaca inversa (primero los operandos y luego los operadores). Por ejemplo: en lugar de 2 + 4, escriba 2 4 + Los dígitos a utilizar son: 4 9 7 5 Introduzca su fórmula en notación polaca inversa: 49*57+- El resultado es = 24 Correcto! ¿Otra ronda? (Pulsa S para salir, u otra tecla para continuar)
Frink
ops = ["+", "-", "*", "/"]
chosen = new array[[4], {|x| random[1,9]}]
println[chosen]
for d = chosen.lexicographicPermute[]
multifor o = [ops, ops, ops]
{
str = "((" + d@0 + o@0 + d@1 + ")" + o@1 + d@2 + ")" + o@2 + d@3
if eval[str] == 24
println[str]
str = "(" + d@0 + o@0 + d@1 + ")" + o@1 + "(" + d@2 + + o@2 + d@3 + ")"
if eval[str] == 24
println[str]
}- Output:
[9, 8, 7, 4] (4+8)*(9-7) ((7+8)-9)*4 ((7-9)+8)*4 (8+4)*(9-7) ((8+7)-9)*4 ((8-9)+7)*4 (8*9)/(7-4) (9-7)*(4+8) (9-7)*(8+4) (9*8)/(7-4)
FutureBasic
24 Game May 17, 2024 Rich Love Thanks to Ken and Bernie
7/7/24 Corrected examples
include resources "24 Game Icon.icns"
#build CompilerOptions @"-Wno-unused-variable"
_mEdit = 2
editmenu _mEdit
begin globals
long gPosition
end globals
void local fn EraseErrorText
CGRect r
r = fn CGRectMake(10, 200, 400, 15)
rect fill r,fn ColorBlack
end fn
local fn ArcRandom( a as long, b as long ) as long
long i
cln i = (arc4random()%(b-a+1))+a;
end fn = fn floor(i)
local fn GetRandomNumbers as CFStringRef
// 96 number groups
CFArrayRef combos = @[¬
// The first 32 are easy
@"1 2 3 4", @"2 4 6 8", @"1 2 4 8", @"1 3 4 6", @"1 2 6 8",
@"2 3 4 8", @"1 3 6 9", @"1 2 7 8", @"2 3 6 8", @"1 4 6 8",
@"2 2 3 9", @"3 4 6 6", @"2 3 3 8", @"1 5 6 6", @"2 4 4 6",
@"1 3 8 8", @"2 2 6 9", @"3 3 6 9", @"1 2 5 9", @"2 4 5 5",
@"1 3 5 9", @"2 2 4 9", @"1 2 3 6", @"1 2 2 9", @"1 2 3 9",
@"1 2 4 6", @"1 2 4 4", @"1 2 2 6", @"1 3 3 6", @"1 1 4 6",
@"1 1 2 8", @"1 1 3 8",
// The middle 32 are medium
@"1 5 5 9", @"4 4 6 9", @"2 3 7 9",@"3 5 8 8", @"1 6 6 8",
@"3 3 5 6", @"1 4 5 8", @"3 3 6 7",@"2 5 5 8", @"4 4 7 9",
@"1 5 6 9", @"3 3 8 9", @"2 6 6 7",@"4 5 7 8", @"2 2 5 9",
@"2 4 6 7", @"1 5 6 8", @"3 4 7 7",@"2 5 6 6", @"3 4 5 9",
@"1 6 7 9", @"2 3 7 8", @"1 4 6 9",@"2 3 5 9", @"3 4 4 8",
@"2 5 8 9", @"1 4 8 9", @"3 3 4 9",@"2 6 7 9", @"1 3 5 7",
@"1 3 6 6", @"2 2 5 7",
// The last 32 are hard
@"1 5 7 9",@"3 4 7 9", @"2 5 7 8", @"3 4 8 9", @"3 4 5 8",
@"2 6 6 9",@"4 4 5 7", @"2 4 6 9", @"1 4 7 7", @"2 3 8 9",
@"2 3 4 7",@"3 3 4 8", @"1 3 7 9", @"2 4 5 9", @"1 3 6 8",
@"2 4 4 9",@"1 5 8 9", @"3 3 5 9", @"2 6 8 9", @"1 4 4 7",
@"2 3 6 7",@"1 3 5 8", @"2 4 7 8", @"1 3 4 7", @"2 3 5 6",
@"1 4 5 6",@"3 3 5 7", @"2 2 3 6", @"3 3 7 7", @"3 3 7 9",
@"4 4 8 9",@"2 4 8 9"]
long i = fn ArcRandom( 0, len(combos) - 1 )
gPosition = i
end fn = combos[i]
local fn EvaluateMath( equation as CFStringRef ) as CFStringRef
equation = fn StringByReplacingOccurrencesOfString( lcase(equation), @"x", @"*" )
CFStringRef result = NULL
RegularExpressionRef regex = fn RegularExpressionWithPattern( @"[0-9.]+", NSRegularExpressionCaseInsensitive, NULL )
CFArrayRef matches = fn RegularExpressionMatches( regex, equation, 0, fn CFRangeMake( 0, len(equation) ) )
NSInteger intConversions = 0
TextCheckingResultRef match
CFRange originalRange
CFRange adjustedRange
CFStringRef value
for match in matches
originalRange = fn TextCheckingResultRange( match )
adjustedRange = fn CFRangeMake( ( originalRange.location + ( intConversions * len( @".0") ) ), originalRange.length )
value = fn StringSubstringWithRange( equation, adjustedRange )
if fn StringContainsString( value, @"." )
continue
else
equation = fn StringByReplacingCharactersInRange( equation, adjustedRange, fn StringWithFormat( @"%@.0", value ) )
intConversions++
end if
next
ExceptionRef e
try
ExpressionRef expression = fn ExpressionWithFormat( equation )
CFNumberRef number = fn ExpressionValueWithObject( expression, NULL, NULL )
result = fn StringWithFormat( @"%.3f", dblval( number ) )
end try
catch (e)
result = fn StringWithFormat( @"%@", e ) : exit fn
end catch
// Test if result is an integer and, if so, return result as an integer
if( fn StringDoubleValue( result ) == fn floorf( fn StringDoubleValue( result ) ) )
result = fn ArrayFirstObject( fn StringComponentsSeparatedByString( result, @"." ) )
end if
end fn = result
local fn QuitOrPlayAlert(GameResult as CFStringRef)
alert -2,,GameResult,@"You won!",@"Quit;Play Again"
AlertButtonSetKeyEquivalent( 2, 2, @"\e" )
short result
result = alert 2
if ( result != NSAlertSecondButtonReturn ) then appterminate
end fn
local fn BuildWindow
CGRect r = fn CGRectMake( 0, 0, 580, 250)
window 1, @"24 Game", r
windowcenter(1)
WindowSetBackgroundColor(1,fn ColorBlack)
end fn
///////// Start //////////
fn BuildWindow
short d(4), i
CFStringRef CheckForDuplicates(97)
for i = 1 to 96
CheckForDuplicates(i) = @""
next i
short DuplicatesCounter
DuplicatesCounter = 0
"Main"
cls
text ,,fn colorWhite
print
print %(10,15),"Given four numbers and using just the +, -, *, and / operators; and the"
print %(10,30),"possible use of parenthesis (), enter an expression that equates to 24."
print %(10,45),"You must use all your numbers and only those numbers."
print %(10,60),"Examples: 9618 Solution 9 + 6 + 1 + 8 or 3173 Solution (3 * 7) - (1 - 4)"
print
print %(10,85),"Enter Q to quit or S to skip to the next number."
"GetFourNumbers"
CFArrayRef randomNumbers : randomNumbers= fn StringComponentsSeparatedByString( fn GetRandomNumbers, @" " )
CFStringRef RandomNumberblock : RandomNumberblock = @""
CFStringRef RandomNumberblockAdd : RandomNumberblockAdd = @""
for i = 0 to 3
// create a string from the 4 numbers
RandomNumberblockAdd = randomNumbers[i]
RandomNumberblock = fn StringByAppendingString(RandomNumberblock,RandomNumberblockAdd)
RandomNumberblock = fn StringByAppendingString(RandomNumberblock,@" ")
next i
if DuplicatesCounter = > 96
// reset counter when last number is retrieved and start from the first number block
DuplicatesCounter = 0
for i = 1 to 96
CheckForDuplicates(i) = @""
next i
end if
for i = 1 to 96
// check the current numbers with the numbers already used
if fn StringIsEqual(RandomNumberblock,CheckForDuplicates(i))
RandomNumberblock = fn StringWithString(CheckForDuplicates(DuplicatesCounter))
goto "GetFourNumbers"
end if
next i
DuplicatesCounter ++
CheckForDuplicates(DuplicatesCounter) = fn StringWithString(RandomNumberblock)
d(1) = fn StringIntegerValue( randomNumbers[0] )
d(2) = fn StringIntegerValue( randomNumbers[1] )
d(3) = fn StringIntegerValue( randomNumbers[2] )
d(4) = fn StringIntegerValue( randomNumbers[3] )
short dots = 0
//d(1) = 9:d(2) = 6:d(3) = 1:d(4) = 8 // Uncomment to test with 9618 numbers. Solution 9 + 6 + 1 + 8
//d(1) = 6:d(2) = 5:d(3) = 3:d(4) = 8 // Uncomment to test with 6538 numbers. Solution 6 / ( 5 - 3 ) * 8
//d(1) = 3:d(2) = 1:d(3) = 7:d(4) = 3 // Uncomment to test with 3773 numbers. Solution ((3 * 1) * 7) + 3
//d(1) = 4:d(2) = 2:d(3) = 7:d(4) = 1 // Uncomment to test with 4271 numbers. Solution (4 * ( 7 - 2 + 1 )
// NOTE: When using these test numbers, also uncomment dots = 0 below here to prevent misleading dot displays
if gPosition <= 32 then dots = 1
if gPosition > 32 and gPosition < 65 then dots = 2
if gPosition > 64 then dots = 3
//dots = 0 uncomment when testing the numbers above to prevent misleading dot displays
print
text ,,fn colorGreen
print %(15,110),"These are your numbers, difficulty level ";
// @"\U000026AA" is white unicode dot - Easy difficulty (One-Dot)
// @"\U0001F534" is red unicode dot - Medium difficulty (Two-Dots)
// @"\U0001F7E1" is yellow unicode dot - Hard difficulty (Three-Dots)
if dots = 1 then print @"\U000026AA Easy"
if dots = 2 then print @"\U0001F534 \U0001F534 Medium"
if dots = 3 then print @"\U0001F7E1 \U0001F7E1 \U0001F7E1 Hard"
print %(55,125)
text ,18,fn colorGreen
for i = 1 to 4
print d(i); " ";
next
print
text ,12,fn colorWhite
printf @"\n\n\n"
CFStringRef expr
bool TryAgain : TryAgain = _false
CFStringRef MessageText
CFStringRef UserInput = NULL
"InputExpression"
if TryAgain
MessageText = fn StringWithFormat( @"Enter math expression: [ '%@' was incorrect ]", expr )
UserInput = input %(10, 190), MessageText, @"123456789+-*/()qs", YES,, 0
else
UserInput = input %(10, 190), @"Enter math expression:", @"123456789+-*/()qs", YES,, 0
end if
if ( UserInput == NULL ) then "InputExpression"
expr = UserInput
if expr = @"" then "InputExpression"
if fn StringIsEqual(ucase(expr) , @"Q") then appterminate
if fn StringIsEqual(ucase(expr) , @"S") then "Main"
//check expr for validity
short j
bool GotAllNumbers : GotAllNumbers = _false
short ThisNumberPosition : ThisNumberPosition = 0
short GotaNumber : GotaNumber = 0
short TotalNumbers : TotalNumbers = 0
short ExtraNumbers:ExtraNumbers = 0
for i = 1 to len$(fn stringpascalstring(expr))
if asc(mid$(fn stringpascalstring(expr),i,1)) > 48 && asc(mid$(fn stringpascalstring(expr),i,1)) < 58
ExtraNumbers ++
end if
next i
if ExtraNumbers > 4
fn EraseErrorText
text ,,fn colorRed
TryAgain = _true
print %(10,200);"Error! Extra numbers not allowed": goto "InputExpression"
text ,,fn colorWhite
end if
for i = 1 to 4
GotaNumber = 0
for j = 0 to len(expr) -1
ThisNumberPosition = instr( j, expr, right(str( d(i)),1 ))
ThisNumberPosition ++
if ThisNumberPosition then GotaNumber = _true
next j
if GotaNumber then TotalNumbers ++
next i
if TotalNumbers => 4 then GotAllNumbers = _true
if GotAllNumbers = _false
fn EraseErrorText
text ,,fn colorRed
TryAgain = _true
print %(10,200);"ERROR! Must use all your numbers and only those numbers." : goto "InputExpression"
text ,,fn colorWhite
end if
fn EraseErrorText
if fn EvaluateMath( expr ) = _false
text ,,fn colorRed
TryAgain = _true
Print %(10,200);"Error! Incorrect math sequence."
goto "InputExpression"
text ,,fn colorWhite
end if
CFStringRef GameResult
if fn StringIntegerValue( fn EvaluateMath( expr ) ) == 24 then GameResult = @"Correct" else GameResult = @"Incorrect"
if GameResult = @"Incorrect"
TryAgain = _true
goto "InputExpression"
end if
fn QuitOrPlayAlert(GameResult)
goto "Main"
handleeventsGAP
Solution in RPN:
Play24 := function()
local input, digits, line, c, chars, stack, stackptr, cur, p, q, ok, a, b, run;
input := InputTextUser();
run := true;
while run do
digits := List([1 .. 4], n -> Random(1, 9));
while true do
Display(digits);
line := ReadLine(input);
line := Chomp(line);
if line = "end" then
run := false;
break;
elif line = "next" then
break;
else
ok := true;
stack := [ ];
stackptr := 0;
chars := "123456789+-*/ ";
cur := ShallowCopy(digits);
for c in line do
if c = ' ' then
continue;
fi;
p := Position(chars, c);
if p = fail then
ok := false;
break;
fi;
if p < 10 then
q := Position(cur, p);
if q = fail then
ok := false;
break;
fi;
Unbind(cur[q]);
stackptr := stackptr + 1;
stack[stackptr] := p;
else
if stackptr < 2 then
ok := false;
break;
fi;
b := stack[stackptr];
a := stack[stackptr - 1];
stackptr := stackptr - 1;
if c = '+' then
a := a + b;
elif c = '-' then
a := a - b;
elif c = '*' then
a := a * b;
elif c = '/' then
if b = 0 then
ok := false;
break;
fi;
a := a / b;
else
ok := false;
break;
fi;
stack[stackptr] := a;
fi;
od;
if ok and stackptr = 1 and Size(cur) = 0 then
if stack[1] = 24 then
Print("Good !\n");
break;
else
Print("Bad value: ", stack[1], "\n");
continue;
fi;
fi;
Print("Invalid expression\n");
fi;
od;
od;
CloseStream(input);
end;
# example session
# type "end" to quit the game, "next" to try another list of digits
gap> Play24();
[ 7, 6, 8, 5 ]
86*75-/
Good !
[ 5, 9, 2, 7 ]
end
gap>
Go
RPN solution.
package main
import (
"fmt"
"math"
"math/rand"
"time"
)
func main() {
rand.Seed(time.Now().Unix())
n := make([]rune, 4)
for i := range n {
n[i] = rune(rand.Intn(9) + '1')
}
fmt.Printf("Your numbers: %c\n", n)
fmt.Print("Enter RPN: ")
var expr string
fmt.Scan(&expr)
if len(expr) != 7 {
fmt.Println("invalid. expression length must be 7." +
" (4 numbers, 3 operators, no spaces)")
return
}
stack := make([]float64, 0, 4)
for _, r := range expr {
if r >= '0' && r <= '9' {
if len(n) == 0 {
fmt.Println("too many numbers.")
return
}
i := 0
for n[i] != r {
i++
if i == len(n) {
fmt.Println("wrong numbers.")
return
}
}
n = append(n[:i], n[i+1:]...)
stack = append(stack, float64(r-'0'))
continue
}
if len(stack) < 2 {
fmt.Println("invalid expression syntax.")
return
}
switch r {
case '+':
stack[len(stack)-2] += stack[len(stack)-1]
case '-':
stack[len(stack)-2] -= stack[len(stack)-1]
case '*':
stack[len(stack)-2] *= stack[len(stack)-1]
case '/':
stack[len(stack)-2] /= stack[len(stack)-1]
default:
fmt.Printf("%c invalid.\n", r)
return
}
stack = stack[:len(stack)-1]
}
if math.Abs(stack[0]-24) > 1e-6 {
fmt.Println("incorrect.", stack[0], "!= 24")
} else {
fmt.Println("correct.")
}
}
Example game:
Your numbers: [5 8 1 3] Enter RPN: 83-5*1- correct.
Gosu
uses java.lang.Double
uses java.lang.Integer
uses java.util.ArrayList
uses java.util.List
uses java.util.Scanner
uses java.util.Stack
function doEval( scanner : Scanner, allowed : List<Integer> ) : double {
var stk = new Stack<Double>()
while( scanner.hasNext() ) {
if( scanner.hasNextInt() ) {
var n = scanner.nextInt()
// Make sure they're allowed to use n
if( n <= 0 || n >= 10 ) {
print( n + " isn't allowed" )
return 0
}
var idx = allowed.indexOf( n )
if( idx == -1 ) {
print( "You aren't allowed to use so many " + n + "s!" )
return 0
}
// Add the input number to the stack
stk.push( new Double( n ) )
// Mark n as used
allowed.remove( idx )
} else {
// It has to be an operator...
if( stk.size() < 2 ) {
print( "Invalid Expression: Stack underflow!" )
return 0
}
// Gets the next operator as a single character token
var s = scanner.next("[\\+-/\\*]")
// Get the operands
var r = stk.pop().doubleValue()
var l = stk.pop().doubleValue()
// Determine which operator and invoke it
if( s.equals( "+" ) ) {
stk.push( new Double( l + r ) )
} else if( s.equals( "-" ) ) {
stk.push( new Double( l - r ) )
} else if( s.equals( "*" ) ) {
stk.push( new Double( l * r ) )
} else if( s.equals( "/" ) ) {
if( r == 0.0 ) {
print( "Invalid Expression: Division by zero!" )
return 0
}
stk.push( new Double( l / r ) )
} else {
print( "Internal Error: looking for operator yielded '" + s + "'" )
return 0
}
}
}
// Did they skip any numbers?
if( allowed.size() != 0 ) {
print( "You didn't use ${allowed}" )
return 0
}
// Did they use enough operators?
if( stk.size() != 1 ) {
print( "Invalid Expression: Not enough operators!" )
return 0
}
return stk.pop().doubleValue()
}
// Pick 4 random numbers from [1..9]
var nums = new ArrayList<Integer>()
var gen = new java.util.Random( new java.util.Date().getTime() )
for( i in 0..3 ) {
nums.add( gen.nextInt(9) + 1 )
}
// Prompt the user
print( "Using addition, subtraction, multiplication and division, write an" )
print( "expression that evaluates to 24 using" )
print( "${nums.get(0)}, ${nums.get(1)}, ${nums.get(2)} and ${nums.get(3)}" )
print( "" )
print( "Please enter your expression in RPN" )
// Build a tokenizer over a line of input
var sc = new Scanner( new java.io.BufferedReader( new java.io.InputStreamReader( java.lang.System.in ) ).readLine() )
// eval the expression
var val = doEval( sc, nums )
// winner?
if( java.lang.Math.abs( val - 24.0 ) < 0.001 ) {
print( "You win!" )
} else {
print( "You lose!" )
}
Groovy
This solution breaks strict adherence to the rules in only one way: any line that starts with the letter "q" causes the game to quit.
final random = new Random()
final input = new Scanner(System.in)
def evaluate = { expr ->
if (expr == 'QUIT') {
return 'QUIT'
} else {
try { Eval.me(expr.replaceAll(/(\d)/, '$1.0')) }
catch (e) { 'syntax error' }
}
}
def readGuess = { digits ->
while (true) {
print "Enter your guess using ${digits} (q to quit): "
def expr = input.nextLine()
switch (expr) {
case ~/^[qQ].*/:
return 'QUIT'
case ~/.*[^\d\s\+\*\/\(\)-].*/:
def badChars = expr.replaceAll(~/[\d\s\+\*\/\(\)-]/, '')
println "invalid characters in input: ${(badChars as List) as Set}"
break
case { (it.replaceAll(~/\D/, '') as List).sort() != ([]+digits).sort() }:
println '''you didn't use the right digits'''
break
case ~/.*\d\d.*/:
println 'no multi-digit numbers allowed'
break
default:
return expr
}
}
}
def digits = (1..4).collect { (random.nextInt(9) + 1) as String }
while (true) {
def guess = readGuess(digits)
def result = evaluate(guess)
switch (result) {
case 'QUIT':
println 'Awwww. Maybe next time?'
return
case 24:
println 'Yes! You got it.'
return
case 'syntax error':
println "A ${result} was found in ${guess}"
break
default:
println "Nope: ${guess} == ${result}, not 24"
println 'One more try, then?'
}
}
Sample Run:
$ groovy TwentyFour.gsh Enter your guess using [4, 8, 3, 6] (q to quit): 4836 no multi-digit numbers allowed Enter your guess using [4, 8, 3, 6] (q to quit): 4 ++ ++ 8/ 3-6 A syntax error was found in 4 ++ ++ 8/ 3-6 Enter your guess using [4, 8, 3, 6] (q to quit): btsjsb invalid characters in input: [t, s, b, j] Enter your guess using [4, 8, 3, 6] (q to quit): 1+3+2+2 you didn't use the right digits Enter your guess using [4, 8, 3, 6] (q to quit): q Awwww. Maybe next time? $ groovy TwentyFour.gsh Enter your guess using [6, 3, 2, 6] (q to quit): 6+6+3+2 Nope: 6+6+3+2 == 17.0, not 24 One more try, then? Enter your guess using [6, 3, 2, 6] (q to quit): (6*3 - 6) * 2 Yes! You got it.
Haskell
import Data.List (sort)
import Data.Char (isDigit)
import Data.Maybe (fromJust)
import Control.Monad (foldM)
import System.Random (randomRs, getStdGen)
import System.IO (hSetBuffering, stdout, BufferMode(NoBuffering))
main = do
hSetBuffering stdout NoBuffering
mapM_
putStrLn
[ "THE 24 GAME\n"
, "Given four digits in the range 1 to 9"
, "Use the +, -, *, and / operators in reverse polish notation"
, "To show how to make an answer of 24.\n"
]
digits <- fmap (sort . take 4 . randomRs (1, 9)) getStdGen :: IO [Int]
putStrLn ("Your digits: " ++ unwords (fmap show digits))
guessLoop digits
where
guessLoop digits =
putStr "Your expression: " >> fmap (processGuess digits . words) getLine >>=
either (\m -> putStrLn m >> guessLoop digits) putStrLn
processGuess _ [] = Right ""
processGuess digits xs
| not matches = Left "Wrong digits used"
where
matches = digits == (sort . fmap read $ filter (all isDigit) xs)
processGuess digits xs = calc xs >>= check
where
check 24 = Right "Correct"
check x = Left (show (fromRational (x :: Rational)) ++ " is wrong")
-- A Reverse Polish Notation calculator with full error handling
calc xs =
foldM simplify [] xs >>=
\ns ->
(case ns of
[n] -> Right n
_ -> Left "Too few operators")
simplify (a:b:ns) s
| isOp s = Right ((fromJust $ lookup s ops) b a : ns)
simplify _ s
| isOp s = Left ("Too few values before " ++ s)
simplify ns s
| all isDigit s = Right (fromIntegral (read s) : ns)
simplify _ s = Left ("Unrecognized symbol: " ++ s)
isOp v = elem v $ fmap fst ops
ops = [("+", (+)), ("-", (-)), ("*", (*)), ("/", (/))]
HicEst
DIMENSION digits(4), input_digits(100), difference(4)
CHARACTER expression*100, prompt*100, answers='Wrong,Correct,', protocol='24 game.txt'
1 digits = CEILING( RAN(9) )
2 DLG(Edit=expression, Text=digits, TItle=prompt)
READ(Text=expression, ItemS=n) input_digits
IF(n == 4) THEN
ALIAS(input_digits,1, input,4)
SORT(Vector=digits, Sorted=digits)
SORT(Vector=input, Sorted=input)
difference = ABS(digits - input)
IF( SUM(difference) == 0 ) THEN
EDIT(Text=expression, ScaNnot='123456789+-*/ ()', GetPos=i, CoPyto=prompt)
IF( i > 0 ) THEN
prompt = TRIM(expression) // ': ' //TRIM(prompt) // ' is an illegal character'
ELSE
prompt = TRIM(expression) // ': Syntax error'
result = XEQ(expression, *2) ! on error branch to label 2
EDIT(Text=answers, ITeM=(result==24)+1, Parse=answer)
WRITE(Text=prompt, Name) TRIM(expression)//': ', answer, result
ENDIF
ELSE
WRITE(Text=prompt) TRIM(expression), ': You used ', input, ' instead ', digits
ENDIF
ELSE
prompt = TRIM(expression) // ': Instead 4 digits you used ' // n
ENDIF
OPEN(FIle=protocol, APPend)
WRITE(FIle=protocol, CLoSe=1) prompt
DLG(TItle=prompt, Button='>2:Try again', B='>1:New game', B='Quit')
END4 + 8 + 7 + 5: You used 4 5 7 8 instead 4 4 7 8
4 + 8 + 7 + a: Instead 4 digits you used 3
4 + 8 + 7 + a + 4: a is an illegal character
4 + 8 + 7a + 4: a is an illegal character
4 + 8 + 7 + 4:; answer=Wrong; result=23;
4 * 7 - 8 + 4:; answer=Correct; result=24;Huginn
#! /bin/sh
exec huginn --no-argv -E "${0}"
#! huginn
import Algorithms as algo;
import Mathematics as math;
import RegularExpressions as re;
make_game( rndGen_ ) {
board = "";
for ( i : algo.range( 4 ) ) {
board += ( " " + string( character( rndGen_.next() + integer( '1' ) ) ) );
}
return ( board.strip() );
}
main() {
rndGen = math.randomizer( 9 );
no = 0;
dd = re.compile( "\\d\\d" );
while ( true ) {
no += 1;
board = make_game( rndGen );
print( "Your four digits: {}\nExpression {}: ".format( board, no ) );
line = input();
if ( line == none ) {
print( "\n" );
break;
}
line = line.strip();
try {
if ( line == "q" ) {
break;
}
if ( ( pos = line.find_other_than( "{}+-*/() ".format( board ) ) ) >= 0 ) {
print( "Invalid input found at: {}, `{}`\n".format( pos, line ) );
continue;
}
if ( dd.match( line ).matched() ) {
print( "Digit concatenation is forbidden.\n" );
continue;
}
res = real( line );
if ( res == 24.0 ) {
print( "Thats right!\n" );
} else {
print( "Bad answer!\n" );
}
} catch ( Exception e ) {
print( "Not an expression: {}\n".format( e.what() ) );
}
}
return ( 0 );
}Icon and Unicon
This plays the game of 24 using a simplified version of the code from the Arithmetic evaluation task.
strings.icn provides deletec and sortc
- Output:
Welcome to 24 The object of the game is to combine the 4 given digits using only + - * / and ( ). All operations have equal precedence and are evaluated left to right. Combining (concatenating) digits is not allowed. Enter 'help', 'quit', or an expression. Your four digits are : 8 1 7 2 8*2+(7+1) Congratulations you win! Your four digits are : 4 2 7 6 7*6+(4*2) Your answer was 50. Try again. Your four digits are : 7 7 8 8 77-88 Invalid expression. Your four digits are : 9 3 2 3 9+3+2+3+ Malformed expression.
J
require'misc'
deal=: 1 + ? bind 9 9 9 9
rules=: smoutput bind 'see http://en.wikipedia.org/wiki/24_Game'
input=: prompt @ ('enter 24 expression using ', ":, ': '"_)
wellformed=: (' '<;._1@, ":@[) -:&(/:~) '(+-*%)' -.&;:~ ]
is24=: 24 -: ". ::0:@]
respond=: (;:'no yes') {::~ wellformed * is24
game24=: (respond input)@deal@rules
Example use:
game24 '' see http://en.wikipedia.org/wiki/24_Game enter 24 expression using 6 5 9 4: 6+5+9+4 yes game24 '' see http://en.wikipedia.org/wiki/24_Game enter 24 expression using 3 3 3 3: 3+3+3+3+3+3+3+3 no
Java
import java.util.*;
public class Game24 {
static Random r = new Random();
public static void main(String[] args) {
int[] digits = randomDigits();
Scanner in = new Scanner(System.in);
System.out.print("Make 24 using these digits: ");
System.out.println(Arrays.toString(digits));
System.out.print("> ");
Stack<Float> s = new Stack<>();
long total = 0;
for (char c : in.nextLine().toCharArray()) {
if ('0' <= c && c <= '9') {
int d = c - '0';
total += (1 << (d * 5));
s.push((float) d);
} else if ("+/-*".indexOf(c) != -1) {
s.push(applyOperator(s.pop(), s.pop(), c));
}
}
if (tallyDigits(digits) != total)
System.out.print("Not the same digits. ");
else if (Math.abs(24 - s.peek()) < 0.001F)
System.out.println("Correct!");
else
System.out.print("Not correct.");
}
static float applyOperator(float a, float b, char c) {
switch (c) {
case '+':
return a + b;
case '-':
return b - a;
case '*':
return a * b;
case '/':
return b / a;
default:
return Float.NaN;
}
}
static long tallyDigits(int[] a) {
long total = 0;
for (int i = 0; i < 4; i++)
total += (1 << (a[i] * 5));
return total;
}
static int[] randomDigits() {
int[] result = new int[4];
for (int i = 0; i < 4; i++)
result[i] = r.nextInt(9) + 1;
return result;
}
}
- Output:
Make 24 using these digits: [1, 2, 4, 8] > 12*48+* Correct!
JavaScript
function twentyfour(numbers, input) {
var invalidChars = /[^\d\+\*\/\s-\(\)]/;
var validNums = function(str) {
// Create a duplicate of our input numbers, so that
// both lists will be sorted.
var mnums = numbers.slice();
mnums.sort();
// Sort after mapping to numbers, to make comparisons valid.
return str.replace(/[^\d\s]/g, " ")
.trim()
.split(/\s+/)
.map(function(n) { return parseInt(n, 10); })
.sort()
.every(function(v, i) { return v === mnums[i]; });
};
var validEval = function(input) {
try {
return eval(input);
} catch (e) {
return {error: e.toString()};
}
};
if (input.trim() === "") return "You must enter a value.";
if (input.match(invalidChars)) return "Invalid chars used, try again. Use only:\n + - * / ( )";
if (!validNums(input)) return "Wrong numbers used, try again.";
var calc = validEval(input);
if (typeof calc !== 'number') return "That is not a valid input; please try again.";
if (calc !== 24) return "Wrong answer: " + String(calc) + "; please try again.";
return input + " == 24. Congratulations!";
};
// I/O below.
while (true) {
var numbers = [1, 2, 3, 4].map(function() {
return Math.