⚠️ Warning: This is a draft ⚠️

This means it might contain formatting issues, incorrect code, conceptual problems, or other severe issues.

If you want to help to improve and eventually enable this page, please fork RosettaGit's repository and open a merge request on GitHub.

;Task: Given a jumbled list of the numbers '''1''' to '''9''' that are definitely ''not'' in ascending order.

Show the list, and then ask the player how many digits from the left to reverse.

Reverse those digits, then ask again, until all the digits end up in ascending order.

The score is the count of the reversals needed to attain the ascending order.

Note: Assume the player's input does not need extra validation.

• [[Sorting algorithms/Pancake sort]]
• [[wp:Pancake sorting|Pancake sorting]].
• [[Topswops]]

```

procedure NumberReverse is

subtype RandRange is Integer range 1..9;
type NumArrayType is array (Integer range 1..9) of Integer;

use RandNumbers;

G : Generator;

procedure FillArray (A : in out NumArrayType) is
Temp : RandRange;
begin
A := (others => 0);
for I in 1..9 loop
Temp := Random(G);
while A(Temp) /= 0 loop
Temp := Random(G);
end loop;
A(Temp) := I;
end loop;
end FillArray;

procedure Put(A : in NumArrayType) is
begin
for I in 1..9 loop
Put(A(I), 0);
Put(" ");
end loop;
end Put;

procedure Prompt (Index : out Integer) is
begin
New_Line;
Put("How many numbers would you like to reverse: ");
Get(Index);
end Prompt;

procedure ReverseArray(Arr : in out NumArrayType;
Index : in Integer) is
Temp : RandRange;
begin
for I in 1..Index/2 loop
Temp := Arr(I);
Arr(I) := Arr(Index + 1 - I);
Arr(Index + 1 - I) := Temp;
end loop;
end ReverseArray;

Sorted : constant NumArrayType := (1,2,3,4,5,6,7,8,9);
Arr    : NumArrayType;
Index  : Integer;
Count  : Integer := 0;
begin
Reset(G);
loop
FillArray(Arr);
exit when Sorted /= Arr;
end loop;
loop
Put(Arr);
Prompt(Index);
Count := Count + 1;
ReverseArray(Arr, Index);
exit when Sorted = Arr;
end loop;
Put(Arr);
New_Line;
Put("Congratulations! You win. It took " &
Integer'Image(Count) & " tries.");
end NumberReverse;

```

## Astro

```print '# Number reversal game'

var data, trials = list(1..9), 0

while data == sort data:
random.shuffle data

while data != sort data:
trials += 1
flip = int input '#\${trials}: LIST: \${join data} Flip how many?: '
data[:flip] = reverse data[:flip]

print '\nYou took \${trials} attempts to put digits in order!'
```

## AutoHotkey

```; Submitted by MasterFocus --- http://tiny.cc/iTunis

ScrambledList := CorrectList := "1 2 3 4 5 6 7 8 9" ; Declare two identical correct sequences
While ( ScrambledList = CorrectList )
Sort, ScrambledList, Random D%A_Space% ; Shuffle one of them inside a While-loop to ensure it's shuffled

Attempts := 0
While ( ScrambledList <> CorrectList ) ; Repeat until the sequence is correct
{
InputBox, EnteredNumber, Number Reversal Game, Attempts so far: %Attempts%`n`nCurrent sequence: %ScrambledList%`n`nHow many numbers (from the left) should be flipped?, , 400, 200
If ErrorLevel
ExitApp ; Exit if user presses ESC or Cancel
If EnteredNumber is not integer
Continue ; Discard attempt if entered number is not an integer
If ( EnteredNumber <= 1 )
Continue ; Discard attempt if entered number is <= 1
Attempts++ ; Increase the number of attempts
; Reverse the first part of the string and add the second part
; The entered number is multiplied by 2 to deal with the spaces
ScrambledList := Reverse(SubStr(ScrambledList,1,(EnteredNumber*2)-1)) SubStr(ScrambledList,EnteredNumber*2)
}

MsgBox, You took %Attempts% attempts to get the correct sequence. ; Final message

Return

;-------------------

Reverse(Str) ; Auxiliar function (flips a string)
{
Loop, Parse, Str
Out := A_LoopField Out
Return Out
}
```

## AWK

```BEGIN {
print "\nWelcome to the number reversal game!\n"

print "You must put the numbers in order from 1 to 9."
print "Your only moves are to reverse groups of numbers"
print "on the left side of the list."

newgame()
prompt()
}

# start a new game
function newgame(  i, j, t) {
# score = number of moves
score = 0

# list = list of numbers
split("123456789", list, "")
do {
# Knuth shuffle
for (i = 9; i > 1; i--) {
j = int(i * rand()) + 1
t = list[i]
list[i] = list[j]
list[j] = t
}
} while (win())
}

# numbers in order?
function win(  i) {
# check if list == 1, list == 2, ...
for (i = 1; i <= 9; i++) if (list[i] != i) return 0
return 1
}

# user prompt
function prompt(  i) {
for (i = 1; i < 9; i++) printf "%d, ", list[i]
printf "%d\n", list

if (win()) {
print "YOU WIN!"
printf "Your score is %d moves.\n", score
printf "Would you like to play again (y/n)? "
again = 1
} else {
printf "How many numbers to reverse? "
}
}

# user input in \$1
{
if (again) {
again = 0
if (tolower(substr(\$1, 1, 1)) == "y")
newgame()
else
exit
} else {
score += 1
reverse(\$1)
}
prompt()
}

function reverse(right,  left, t) {
left = 1
while (right > left) {
t = list[left]
list[left] = list[right]
list[right] = t
left++
right--
}
}

END { print "\n\nBye!" }
```

## BASIC

{{works with|QBasic}}

{{works with|FreeBASIC}}

```PRINT "Given a jumbled list of the numbers 1 to 9,"
PRINT "you must select how many digits from the left to reverse."
PRINT "Your goal is to get the digits in order with 1 on the left and 9 on the right."

RANDOMIZE TIMER

DIM nums(1 TO 9) AS INTEGER
DIM L0 AS INTEGER, n AS INTEGER, flp AS INTEGER, tries AS INTEGER, again AS INTEGER

'initial values
FOR L0 = 1 TO 9
nums(L0) = L0
NEXT

DO  'shuffle
FOR L0 = 9 TO 2 STEP -1
n = INT(RND * (L0)) + 1
IF n <> L0 THEN SWAP nums(n), nums(L0)
NEXT
FOR L0 = 1 TO 8 'make sure it's not in order
IF nums(L0) > nums(L0 + 1) THEN EXIT DO
NEXT
LOOP

again = -1
DO
IF tries < 10 THEN PRINT " ";
PRINT tries; ":";
FOR L0 = 1 TO 9
PRINT nums(L0);
NEXT

IF NOT again THEN EXIT DO

INPUT " -- How many numbers should be flipped"; flp
IF flp < 0 THEN flp = 0
IF flp > 9 THEN flp = 0

FOR L0 = 1 TO (flp \ 2)
SWAP nums(L0), nums(flp - L0 + 1)
NEXT

again = 0
'check for order
FOR L0 = 1 TO 8
IF nums(L0) > nums(L0 + 1) THEN
again = -1
EXIT FOR
END IF
NEXT

IF flp > 0 THEN tries = tries + 1
LOOP

PRINT : PRINT "You took "; LTRIM\$(RTRIM\$(STR\$(tries))); " tries to put the digits in order."
```

Sample output:

```
Given a jumbled list of the numbers 1 to 9,
you must select how many digits from the left to reverse.
Your goal is to get the digits in order with 1 on the left and 9 on the right.
0 : 1  4  5  3  2  7  6  8  9  -- How many numbers should be flipped? 7
1 : 6  7  2  3  5  4  1  8  9  -- How many numbers should be flipped? 2
2 : 7  6  2  3  5  4  1  8  9  -- How many numbers should be flipped? 7
3 : 1  4  5  3  2  6  7  8  9  -- How many numbers should be flipped? 3
4 : 5  4  1  3  2  6  7  8  9  -- How many numbers should be flipped? 5
5 : 2  3  1  4  5  6  7  8  9  -- How many numbers should be flipped? 2
6 : 3  2  1  4  5  6  7  8  9  -- How many numbers should be flipped? 3
7 : 1  2  3  4  5  6  7  8  9
You took 7  tries to put the digits in order.

```

## BASIC256

```
print "Dada una lista aleatoria de numeros del 1 al 9,"
print "indica cuantos digitos de la izquierda voltear."
print " El objetivo es obtener los digitos en orden "
print " con el 1 a la izquierda y el 9 a la derecha." + chr(10)

dim nums(10)
dim a(10)
intentos = 0: denuevo = true: colum = 6

#valores iniciales
for i = 1 to 9
nums[i] = i
next i

do  #barajamos
for i = 9 to 2 step -1
n = int(rand * i) + 1
if n <> i then
a[i] = nums[i]
nums[i] = nums[n]
nums[n] = a[i]
end if
next i
for i = 1 to 8 #nos aseguramos que no estén en orden
if nums[i] > nums[i + 1] then exit do
next i
until false

do
if intentos < 10 then print " ";
print intentos; ": ";
for i = 1 to 9
print nums[i];" ";
next i

if not denuevo then exit do

input "  -- Cuantos volteamos ", volteo
if volteo < 0 or volteo > 9 then volteo = 0

for i = 1 to (volteo \ 2)
a[i] = nums[volteo - i + 1]
nums[volteo - i + 1] = nums[i]
nums[i] = a[i]
next i

denuevo = false
#comprobamos el orden
for i = 1 to 8
if nums[i] > nums[i + 1] then
denuevo = true
exit for
end if
next i

if volteo > 0 then intentos += 1
until false
print chr(10) + chr(10) + "   Necesitaste "; intentos; " intentos."
end

```

{{out}}

```
Dada una lista aleatoria de numeros del 1 al 9,
indica cuantos digitos de la izquierda voltear.
El objetivo es obtener los digitos en orden
con el 1 a la izquierda y el 9 a la derecha.

0: 2 1 4 3 5 9 8 6 7   -- Cuantos volteamos 6
1: 9 5 3 4 1 2 8 6 7   -- Cuantos volteamos 9
2: 7 6 8 2 1 4 3 5 9   -- Cuantos volteamos 3
3: 8 6 7 2 1 4 3 5 9   -- Cuantos volteamos 8
4: 5 3 4 1 2 7 6 8 9   -- Cuantos volteamos 6
5: 7 2 1 4 3 5 6 8 9   -- Cuantos volteamos 7
6: 6 5 3 4 1 2 7 8 9   -- Cuantos volteamos 6
7: 2 1 4 3 5 6 7 8 9   -- Cuantos volteamos 3
8: 4 1 2 3 5 6 7 8 9   -- Cuantos volteamos 4
9: 3 2 1 4 5 6 7 8 9   -- Cuantos volteamos 3
10: 1 2 3 4 5 6 7 8 9

Necesitaste 10 intentos.

```

## Batch File

Note that I did not use the FOR command for looping. I used Batch File labels instead.

```
::
::Number Reversal Game Task from Rosetta Code Wiki
::Batch File Implementation
::
::Please do not open this from command prompt.
::Directly Open the Batch File to play...
::

@echo off
setlocal enabledelayedexpansion
title Number Reversal Game

:begin
set score=0

::The ascending list of 9 digits
set list=123456789

::Generating a random set of 9 digits...
set cyc=9
:gen
set /a tmp1=%random%%%%cyc%
set n%cyc%=!list:~%tmp1%,1!
set tmp2=!n%cyc%!
set list=!list:%tmp2%=!
if not %cyc%==2 (
set /a cyc-=1
goto :gen
)
set /a n1=%list%

::Display the Game
cls
echo.
echo ***Number Reversal Game***
:loopgame
echo.
echo Current arrangement: %n1%%n2%%n3%%n4%%n5%%n6%%n7%%n8%%n9%
set /p move=How many digits from the left should I reverse?

::Reverse digits according to the player's input
::NOTE: The next command uses the fact that in Batch File,
::The output for the division operation is only the integer part of the quotient.
set /a lim=(%move%+1)/2

set cyc2=1
:reverse
set /a tmp4=%move%-%cyc2%+1
set tmp5=!n%cyc2%!
set n%cyc2%=!n%tmp4%!
set n%tmp4%=%tmp5%
if not %cyc2%==%lim% (
set /a cyc2+=1
goto :reverse
)

::Increment the number of moves took by the player
set /a score+=1

if %n1%%n2%%n3%%n4%%n5%%n6%%n7%%n8%%n9%==123456789 (
echo.
echo Set: %n1%%n2%%n3%%n4%%n5%%n6%%n7%%n8%%n9% DONE^^!
echo You took %score% moves to arrange the numbers in ascending order.
pause>nul
exit
) else (
goto :loopgame
)

```

Sample Output:

```
***Number Reversal Game***

Current arrangement: 349718652
How many digits from the left should I reverse?3

Current arrangement: 943718652
How many digits from the left should I reverse?9

Current arrangement: 256817349
How many digits from the left should I reverse?4

Current arrangement: 865217349
How many digits from the left should I reverse?8

Current arrangement: 437125689
How many digits from the left should I reverse?3

Current arrangement: 734125689
How many digits from the left should I reverse?7

Current arrangement: 652143789
How many digits from the left should I reverse?6

Current arrangement: 341256789
How many digits from the left should I reverse?2

Current arrangement: 431256789
How many digits from the left should I reverse?4

Current arrangement: 213456789
How many digits from the left should I reverse?2

Set: 123456789 DONE!
You took 10 moves to arrange the numbers in ascending order.

```

## BBC BASIC

Note the use of the MOD(array()) function to test the equality of two arrays.

```      DIM list%(8), done%(8), test%(8)
list%() = 1, 2, 3, 4, 5, 6, 7, 8, 9
done%() = list%()

REM Shuffle:
REPEAT
FOR i% = 9 TO 2 STEP -1
SWAP list%(i%-1), list%(RND(i%)-1)
NEXT
test%() = list%() - done%()
UNTIL MOD(test%()) <> 0

REM Run the game:
tries% = 0
REPEAT
tries% += 1
FOR i% = 0 TO 8 : PRINT ; list%(i%) " " ; : NEXT
INPUT ": Reverse how many", n%
PROCreverse(list%(), n%)
test%() = list%() - done%()
UNTIL MOD(test%()) = 0
PRINT "You took " ; tries% " attempts."
END

DEF PROCreverse(a%(), n%)
IF n% < 2 ENDPROC
LOCAL i%
n% -= 1
FOR i% = 0 TO n% DIV 2
SWAP a%(i%), a%(n%-i%)
NEXT
ENDPROC
```

'''Output:'''

```
7 2 3 1 5 8 6 4 9 : Reverse how many? 6
8 5 1 3 2 7 6 4 9 : Reverse how many? 8
4 6 7 2 3 1 5 8 9 : Reverse how many? 3
7 6 4 2 3 1 5 8 9 : Reverse how many? 7
5 1 3 2 4 6 7 8 9 : Reverse how many? 5
4 2 3 1 5 6 7 8 9 : Reverse how many? 4
1 3 2 4 5 6 7 8 9 : Reverse how many? 3
2 3 1 4 5 6 7 8 9 : Reverse how many? 2
3 2 1 4 5 6 7 8 9 : Reverse how many? 3
You took 9 attempts.

```

## Brat

```sorted = 1.to 9
length = sorted.length
numbers = sorted.shuffle

#Make certain numbers are shuffled
true? numbers == sorted
{ while { sorted == numbers.shuffle! } }

turns = 0

while { numbers != sorted } {
print "#{numbers} - How many to reverse? "
num  = g.to_i
numbers = numbers[0, num - 1].reverse + numbers[num, length]
turns = turns + 1
}

p numbers
p "It took #{turns} turns to sort numbers."
```

## C

An example of a number reversal game could be:

```void number_reversal_game()
{
printf("Number Reversal Game. Type a number to flip the first n numbers.");
printf("Win by sorting the numbers in ascending order.\n");
printf("Anything besides numbers are ignored.\n");
printf("\t  |1__2__3__4__5__6__7__8__9|\n");
int list = {1,2,3,4,5,6,7,8,9};
shuffle_list(list,9);

int tries=0;
unsigned int i;
int input;

while(!check_array(list, 9))
{
((tries<10) ? printf("Round %d :  ", tries) : printf("Round %d : ", tries));
for(i=0;i<9;i++)printf("%d  ",list[i]);
printf("  Gimme that number:");
while(1)
{
//Just keep asking for proper input
scanf("%d", &input);
if(input>1&&input<10)
break;

printf("\n%d - Please enter a number between 2 and 9:", (int)input);
}
tries++;
do_flip(list, 9, input);
}
printf("Hurray! You solved it in %d moves!\n", tries);
}
```

Which uses the following helper functions:

```void shuffle_list(int *list, int len)
{
//We'll just be swapping 100 times. Could be more/less. Doesn't matter much.
int n=100;
int a=0;
int b=0;
int buf = 0;
//Random enough for common day use..
srand(time(NULL));
while(n--)
{
//Get random locations and swap
a = rand()%len;
b = rand()%len;
buf = list[a];
list[a] = list[b];
list[b] = buf;
}
// "shuffled to ordered state" fix:
if (check_array(list, len)) shuffle_list (list, len);
}

void do_flip(int *list, int length, int num)
{
//Flip a part on an array
int swap;
int i=0;
for(i;i<--num;i++)
{
swap=list[i];
list[i]=list[num];
list[num]=swap;
}
}

int check_array(int *arr, int len)
{
while(--len)
{
if(arr[len]!=(arr[len-1]+1))
return 0;
}
return 1;
}
```

## C#

C# 3.0

```using System;
using System.Linq;

class Program
{
static void Main(string[] args)
{
var r = new Random();

var tries = 1;
var sorted = Enumerable.Range(1, 9).ToList();
var values = sorted.OrderBy(x => r.Next(-1, 1)).ToList();

while (Enumerable.SequenceEqual(sorted, values)) {
values = sorted.OrderBy(x => r.Next(-1, 1)).ToList();
}

//values = "1 3 9 2 7 5 4 8 6".Split().Select(x => int.Parse(x)).ToList();

while (!Enumerable.SequenceEqual(sorted, values))
{
Console.Write("# {0}: LIST: {1} - Flip how many? ", tries, String.Join(" ", values));

tries += 1;
}

Console.WriteLine("\nYou took {0} attempts to put the digits in order!", tries - 1);
}
}
```

C# 1.0

```class Program
{
static void Main(string[] args)
{
int[] values = new int;
Random tRandom = new Random();
int tries = 0;

for (int x = 0; x < values.Length; x++)
{
values[x] = x + 1;
}

values = RandomPermutation<int>(values);

do
{
Console.Write("Numbers: ");
for (int x = 0; x < values.Length; x++)
{
Console.Write(" ");
Console.Write(values[x]);
}
Console.WriteLine(". Enter number of numbers from the left to reverse: ");

string tIn = "";
do
{
} while (tIn.Length != 1);

int nums = Convert.ToInt32(tIn.ToString());

int[] newValues = new int;
for (int x = nums; x < newValues.Length; x++)
{
// Move those not reversing
newValues[x] = values[x];
}
for (int x = 0; x < nums; x++)
{
// Reverse the rest
newValues[x] = values[nums - 1 - x];
}
values = newValues;
tries++;
} while (!check(values));

Console.WriteLine("Success!");
Console.WriteLine("Attempts: " + tries);

}

public static bool check(int[] p)
{
// Check all items
for (int x = 0; x < p.Length - 1; x++)
{
if (p[x + 1] <= p[x])
return false;
}

return true;
}

public static T[] RandomPermutation<T>(T[] array)
{
T[] retArray = new T[array.Length];
array.CopyTo(retArray, 0);

Random random = new Random();
for (int i = 0; i < array.Length; i += 1)
{
int swapIndex = random.Next(i, array.Length);
if (swapIndex != i)
{
T temp = retArray[i];
retArray[i] = retArray[swapIndex];
retArray[swapIndex] = temp;
}
}

return retArray;
}
}
```

## C++

The C code can be used with C++, although the following uses proper C++ iostreams:

```void number_reversal_game()
{
cout << "Number Reversal Game. Type a number to flip the first n numbers.";
cout << "You win by sorting the numbers in ascending order.";
cout << "Anything besides numbers are ignored.\n";
cout << "\t  |1__2__3__4__5__6__7__8__9|\n";
int list = {1,2,3,4,5,6,7,8,9};
do
{
shuffle_list(list,9);
} while(check_array(list, 9));

int tries=0;
unsigned int i;
int input;

while(!check_array(list, 9))
{
cout << "Round " << tries << ((tries<10) ? " :  " : " : ");
for(i=0;i<9;i++)cout << list[i] << "  ";
cout << "  Gimme that number:";
while(1)
{
cin >> input;
if(input>1&&input<10)
break;

cout << "\nPlease enter a number between 2 and 9:";
}
tries++;
do_flip(list, 9, input);
}
cout << "Hurray! You solved it in %d moves!\n";
}
```

This uses the same helper functions as the C version.

### Alternate version using the C++ standard library

This version uses the C++ standard library (note that none of the C helper functions are needed).

```
#include <iostream>
#include <algorithm>
#include <functional>
#include <iterator>
#include <cstdlib>
#include <ctime>

template<typename T, int size>
bool is_sorted(T (&array)[size])
{
== array+size;
}

int main()
{
std::srand(std::time(0));

int list[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9 };

do
{
std::random_shuffle(list, list+9);
} while (is_sorted(list));

int score = 0;

do
{
std::cout << "Current list: ";
std::copy(list, list+9, std::ostream_iterator<int>(std::cout, " "));

int rev;
while (true)
{
std::cout << "\nDigits to reverse? ";
std::cin >> rev;
if (rev > 1 && rev < 10)
break;
std::cout << "Please enter a value between 2 and 9.";
}

++score;
std::reverse(list, list + rev);
} while (!is_sorted(list));

std::cout << "Congratulations, you sorted the list.\n"
<< "You needed " << score << " reversals." << std::endl;
return 0;
}

```

## Clojure

```(defn flip-at [n coll]
(let [[x y] (split-at n coll)]
(concat (reverse x) y )))

(def sorted '(1 2 3 4 5 6 7 8 9))  ; i.e. (range 1 10)
(def unsorted? #(not= % sorted))

(loop [unsorted (first (filter unsorted? (iterate shuffle sorted))), steps 0]
(if (= unsorted sorted)
(printf "Done! That took you %d steps%n" steps)
(do
(println unsorted)
(printf "Reverse how many? ")
(flush)
(recur (flip-at flipcount unsorted), (inc steps))))))
```

## Common Lisp

```(defun shuffle! (vector)
(loop for i from (1- (length vector)) downto 1
do (rotatef (aref vector i)
(aref vector (random i)))))

(defun slice (vector start &optional end)
(let ((end (or end (length vector))))
(make-array (- end start)
:element-type (array-element-type vector)
:displaced-to vector
:displaced-index-offset start)))

(defun orderedp (seq)
(apply #'<= (coerce seq 'list)))

(defun prompt-integer (prompt)
(format t "~A: " prompt)
(finish-output)
(clear-input)

(defun game ()
(let ((numbers (vector 1 2 3 4 5 6 7 8 9)))
(shuffle! numbers)
(let ((score
(do ((score 0 (1+ score)))
((orderedp numbers) score)
(format t "~A~%" numbers)
(let* ((n (prompt-integer "How many numbers to reverse"))
(slice (slice numbers 0 n)))
(replace slice (nreverse slice))))))
(format t "~A~%Congratulations, you did it in ~D reversals!~%" numbers score))))

```

## Crystal

```
SIZE = 9
ordered = (1..SIZE).to_a
shuffled = (1..SIZE).to_a

while shuffled == ordered
shuffled.shuffle!
end

score = 0
until shuffled == ordered
print "#{shuffled} Enter items to reverse: "

next unless guess = gets
next unless num = guess.to_i?
next if num < 2 || num > SIZE

shuffled[0, num] = shuffled[0, num].reverse
score += 1
end

```

## D

```import std.stdio, std.random, std.string, std.conv, std.algorithm,
std.range;

void main() {
auto data = iota(1, 10).array;
do data.randomShuffle;
while (data.isSorted);

int trial;
while (!data.isSorted) {
writef("%d: %s How many numbers to flip? ", ++trial, data);
}
writefln("\nYou took %d attempts.", trial);
}
```

{{out}}

```1: [7, 2, 1, 6, 3, 8, 9, 5, 4] How many numbers to flip? 7
2: [9, 8, 3, 6, 1, 2, 7, 5, 4] How many numbers to flip? 9
3: [4, 5, 7, 2, 1, 6, 3, 8, 9] How many numbers to flip? 3
4: [7, 5, 4, 2, 1, 6, 3, 8, 9] How many numbers to flip? 7
5: [3, 6, 1, 2, 4, 5, 7, 8, 9] How many numbers to flip? 2
6: [6, 3, 1, 2, 4, 5, 7, 8, 9] How many numbers to flip? 6
7: [5, 4, 2, 1, 3, 6, 7, 8, 9] How many numbers to flip? 5
8: [3, 1, 2, 4, 5, 6, 7, 8, 9] How many numbers to flip? 3
9: [2, 1, 3, 4, 5, 6, 7, 8, 9] How many numbers to flip? 2

You took 9 attempts.
```

## Egel

```
import "prelude.eg"
import "io.ego"
import "random.ego"

using System
using IO
using List
using Math

def swap =
[ (I J) XX -> insert I (nth J XX) (insert J (nth I XX) XX) ]

def shuffle =
[ XX ->
let INDICES = reverse (fromto 0 ((length XX) - 1)) in
let SWAPS = map [ I -> I (between 0 I) ] INDICES in
foldr [I J -> swap I J] XX SWAPS ]

def prompt =
[ XX TURN ->
let _ = print TURN ". " in
let _ = map [ X -> print X " " ] XX in
let _ = print " : " in
toint getline ]

def game =
[ GOAL SHUFFLE TURN ->
if SHUFFLE == GOAL then
let _ = print "the goal was " in
let _ = map [ X -> print X " " ] GOAL in
print "\nit took you " TURN " turns\n"
else
let N = prompt SHUFFLE TURN in
let YY = (reverse (take N SHUFFLE)) ++ (drop N SHUFFLE) in
game GOAL YY (TURN + 1) ]

def main =
let XX = fromto 1 9 in game XX (shuffle XX) 0
```

## Eiffel

```
class
APPLICATION

create
make

feature {NONE}

make
-- Plays Number Reversal Game.
local
count: INTEGER
do
initialize_game
io.put_string ("Let's play the number reversal game.%N")
across
numbers as ar
loop
io.put_string (ar.item.out + "%T")
end
from
until
is_sorted (numbers, 1, numbers.count)
loop
io.put_string ("%NHow many numbers should be reversed?%N")
reverse_array (io.last_integer)
across
numbers as ar
loop
io.put_string (ar.item.out + "%T")
end
count := count + 1
end
io.put_string ("%NYou needed " + count.out + " reversals.")
end

feature {NONE}

initialize_game
-- Array with numbers from 1 to 9 in a random unsorted order.
local
random: V_RANDOM
item, i: INTEGER
do
create random
create numbers.make_empty
from
i := 1
until
numbers.count = 9 and not is_sorted (numbers, 1, numbers.count)
loop
item := random.bounded_item (1, 9)
if not numbers.has (item) then
numbers.force (item, i)
i := i + 1
end
random.forth
end
end

numbers: ARRAY [INTEGER]

reverse_array (upper: INTEGER)
-- Array numbers with first element up to nth element reversed.
require
upper_positive: upper > 0
ar_not_void: numbers /= Void
local
i, j: INTEGER
new_array: ARRAY [INTEGER]
do
create new_array.make_empty
new_array.deep_copy (numbers)
from
i := 1
j := upper
until
i > j
loop
new_array [i] := numbers [j]
new_array [j] := numbers [i]
i := i + 1
j := j - 1
end
numbers := new_array
end

is_sorted (ar: ARRAY [INTEGER]; l, r: INTEGER): BOOLEAN
-- Is Array 'ar' sorted in ascending order?
require
ar_not_empty: not ar.is_empty
do
Result := True
across
1 |..| (r - 1) as c
loop
if ar [c.item] > ar [c.item + 1] then
Result := False
end
end
end

end

```

{{out}}

```
Let's play the number reversal game.
7 8 5 6 9 6 1 4 2
How many numbers should be reversed?
5
9 3 5 8 7 6 1 4 2
How many numbers should be reversed?
9
2 4 1 6 7 8 5 3 9
How many numbers should be reversed?
6
8 7 6 1 4 2 5 3 9
How many numbers should be reversed?
8
3 5 2 4 1 6 7 8 9
How many numbers should be reversed?
2
5 3 2 4 1 6 7 8 9
How many numbers should be reversed?
5
1 4 2 3 5 6 7 8 9
How many numbers should be reversed?
2
4 1 2 3 5 6 7 8 9
How many numbers should be reversed?
4
3 2 1 4 5 6 7 8 9
How many numbers should be reversed?
3
1 2 3 4 5 6 7 8 9
You needed 9 reversals.

```

## Elena

ELENA 4.x:

```import system'routines;
import extensions;

public program()
{
var sorted := Array.allocate(9).populate:(n => n + 1 );
var values := sorted.clone().randomize:9;

while (sorted.sequenceEqual:values)
{
values := sorted.randomize:9
};

var tries := new Integer();
until (sorted.sequenceEqual:values)
{
tries.append:1;

console.print("# ",tries," : LIST : ",values," - Flip how many?");

};

console.printLine("You took ",tries," attempts to put the digits in order!").readChar()
}
```

## Elixir

{{trans|Erlang}}

```defmodule Number_reversal_game do
def start( n ) when n > 1 do
IO.puts "Usage: #{usage(n)}"
targets = Enum.to_list( 1..n )
jumbleds = Enum.shuffle(targets)
attempt = loop( targets, jumbleds, 0 )
IO.puts "Numbers sorted in #{attempt} atttempts"
end

defp loop( targets, targets, attempt ), do: attempt
defp loop( targets, jumbleds, attempt ) do
IO.inspect jumbleds
{n,_} = IO.gets("How many digits from the left to reverse? ") |> Integer.parse
loop( targets, Enum.reverse_slice(jumbleds, 0, n), attempt+1 )
end

defp usage(n), do: "Given a jumbled list of the numbers 1 to #{n} that are definitely not in ascending order, show the list then ask the player how many digits from the left to reverse. Reverse those digits, then ask again, until all the digits end up in ascending order."
end

Number_reversal_game.start( 9 )
```

{{out}}

```
Usage: Given a jumbled list of the numbers 1 to 9 that are definitely not in ascending order, show the list then ask the player how many digits from the left to reverse. Reverse those digits, then ask again, until all he digits end up in ascending order.
[3, 9, 4, 7, 6, 5, 1, 2, 8]
How many digits from the left to reverse? 2
[9, 3, 4, 7, 6, 5, 1, 2, 8]
How many digits from the left to reverse? 9
[8, 2, 1, 5, 6, 7, 4, 3, 9]
How many digits from the left to reverse? 8
[3, 4, 7, 6, 5, 1, 2, 8, 9]
How many digits from the left to reverse? 3
[7, 4, 3, 6, 5, 1, 2, 8, 9]
How many digits from the left to reverse? 7
[2, 1, 5, 6, 3, 4, 7, 8, 9]
How many digits from the left to reverse? 4
[6, 5, 1, 2, 3, 4, 7, 8, 9]
How many digits from the left to reverse? 6
[4, 3, 2, 1, 5, 6, 7, 8, 9]
How many digits from the left to reverse? 4
Numbers sorted in 8 atttempts

```

## Erlang

```
-module( number_reversal_game ).

start( N ) when N > 1 ->
io:fwrite( "Usage: ~s~n", [usage(N)] ),
Targets = lists:seq( 1, N ),
Jumbleds = [X||{_,X} <- lists:sort([ {random:uniform(), Y} || Y <- Targets])],
Attempt = loop( Targets, Jumbleds, 0 ),
io:fwrite( "Numbers sorted in ~p atttempts~n", [Attempt] ).

loop( Targets, Targets, Attempt ) -> Attempt;
loop( Targets, Jumbleds, Attempt ) ->
io:fwrite( "~p~n", [Jumbleds] ),
{ok,[N]} = io:fread( "How many digits from the left to reverse? ", "~d" ),
{Lefts, Rights} = lists:split( N, Jumbleds ),
loop( Targets, lists:reverse(Lefts) ++ Rights, Attempt + 1 ).

usage(N) -> io_lib:format( "Given a jumbled list of the numbers 1 to ~p that are definitely not in ascending order, show the list then ask the player how many digits from the left to reverse. Reverse those digits, then ask again, until all the digits end up in ascending order.", [N] ).

```

{{out}} Not being a very good player I show a test run with only 3 numbers.

```
35> number_reversal_game:start(3).
Usage: Given a jumbled list of the numbers 1 to 3 that are definitely not in ascending order, show
the list then ask the player how many digits from the left to reverse. Reverse those digits, then
ask again, until all the digits end up in ascending order.
[2,3,1]
How many digits from the left to reverse? 3
[1,3,2]
How many digits from the left to reverse? 3
[2,3,1]
How many digits from the left to reverse? 2
[3,2,1]
How many digits from the left to reverse? 3
Numbers sorted in 4 atttempts

```

## Euphoria

```include get.e

function accending(sequence s)
for i = 1 to length(s)-1 do
if s[i]>s[i+1] then
return 0
end if
end for
return 1
end function

puts(1,"Given a jumbled list of the numbers 1 to 9,\n")
puts(1,"you must select how many digits from the left to reverse.\n")
puts(1,"Your goal is to get the digits in order with 1 on the left and 9 on the right.\n")

sequence nums
nums = repeat(0,9)
integer n,flp,tries,temp

-- initial values
for i = 1 to 9 do
nums[i] = i
end for

while accending(nums) do -- shuffle
for i = 1 to 9 do
n = rand(9)
temp = nums[n]
nums[n] = nums[i]
nums[i] = temp
end for
end while

tries = 0
while 1 do
printf(1,"%2d : ",tries)
for i = 1 to 9 do
printf(1,"%d ",nums[i])
end for

if accending(nums) then
exit
end if

flp = prompt_number(" -- How many numbers should be flipped? ",{1,9})
for i = 1 to flp/2 do
temp = nums[i]
nums[i] = nums[flp-i+1]
nums[flp-i+1] = temp
end for

tries += 1
end while

printf(1,"\nYou took %d tries to put the digits in order.", tries)
```

Output:

```Given a jumbled list of the numbers 1 to 9,
you must select how many digits from the left to reverse.
Your goal is to get the digits in order with 1 on the left and 9 on the right.
0 : 4 8 7 5 1 6 3 9 2  -- How many numbers should be flipped? 8
1 : 9 3 6 1 5 7 8 4 2  -- How many numbers should be flipped? 9
2 : 2 4 8 7 5 1 6 3 9  -- How many numbers should be flipped? 3
3 : 8 4 2 7 5 1 6 3 9  -- How many numbers should be flipped? 8
4 : 3 6 1 5 7 2 4 8 9  -- How many numbers should be flipped? 5
5 : 7 5 1 6 3 2 4 8 9  -- How many numbers should be flipped? 7
6 : 4 2 3 6 1 5 7 8 9  -- How many numbers should be flipped? 4
7 : 6 3 2 4 1 5 7 8 9  -- How many numbers should be flipped? 6
8 : 5 1 4 2 3 6 7 8 9  -- How many numbers should be flipped? 5
9 : 3 2 4 1 5 6 7 8 9  -- How many numbers should be flipped? 3
10 : 4 2 3 1 5 6 7 8 9  -- How many numbers should be flipped? 4
11 : 1 3 2 4 5 6 7 8 9  -- How many numbers should be flipped? 2
12 : 3 1 2 4 5 6 7 8 9  -- How many numbers should be flipped? 3
13 : 2 1 3 4 5 6 7 8 9  -- How many numbers should be flipped? 2
14 : 1 2 3 4 5 6 7 8 9
You took 14 tries to put the digits in order.
```

```let rand = System.Random()

while true do
let rec randomNums() =
let xs = [|for i in 1..9 -> rand.Next(), i|] |> Array.sort |> Array.map snd
if xs = Array.sort xs then randomNums() else xs

let xs = randomNums()

let suffix = function | 1 -> "st" | 2 -> "nd" | 3 -> "rd" | _ -> "th"

let rec move i =
printf "\n%A\n\nReverse how many digits from the left in your %i%s move? : " xs i (suffix i)
let n = stdin.ReadLine() |> int
Array.blit (Array.rev xs.[0..n-1]) 0 xs 0 n
if xs <> Array.sort xs then
move (i+1)
else
printfn "\nYou took %i moves to put the digits in order!\n" i

move 1
```

## Factor

```USING: formatting io kernel math math.parser math.ranges
namespaces random sequences strings ;
IN: rosetta.number-reversal

: make-jumbled-array ( -- sorted jumbled )
CHAR: 1 CHAR: 9 [a,b] [ 1string ] map dup clone randomize
[ 2dup = ] [ randomize ] while ;

SYMBOL: trials

: prompt ( jumbled -- n )
trials get "#%2d: " printf
", " join write
"   Flip how many? " write flush

: game-loop ( sorted jumbled -- )
2dup = [
2drop trials get
"\nYou took %d attempts to put the digits in order!\n" printf
flush
] [
trials [ 1 + ] change
dup dup prompt head-slice reverse! drop
game-loop
] if ;

: play ( -- )
0 trials set
make-jumbled-array game-loop ;
```

## Forth

```include random.fs

variable flips
create nums 9 cells allot

: .array ( addr len -- ) 0 ?do dup @ . cell+ loop drop ;

: shuffle ( addr len -- )
2 swap do
dup i random cells +
over @ over @  swap
rot  ! over !
cell+
-1 +loop drop ;

: sorted? ( addr len -- )
1- cells bounds ?do
i 2@ < if unloop false exit then
cell +loop true ;

: init
0 flips !
nums 10 1 do
i over !  cell+
loop drop
begin nums 9 shuffle nums 9 sorted? 0= until
cr nums 9 .array ;

: reverse ( addr len -- )
1- cells bounds
begin 2dup >
while over @ over @ >r over ! over r> swap !
cell+ swap 1 cells - swap
repeat 2drop ;

: flip ( n -- )
dup 2 10 within 0= if . ." must be within 2 to 9" exit then
nums swap reverse
1 flips +!
nums 9 sorted? if
cr ." Got it in " flips @ . ." tries!"
else
cr nums 9 .array
then ;

init
1 2 8 5 7 6 9 4 3  ok
7 flip
9 6 7 5 8 2 1 4 3  ok

```

## Fortran

{{works with|Fortran|95 and later}}

```program Reversal_game
implicit none

integer :: list(9) = (/ 1, 2, 3, 4, 5, 6, 7, 8, 9 /)
integer :: pos, attempts = 0

call random_seed
do while (sorted(list))
call Shuffle(list)
end do
write(*, "(9i5)") list
write(*,*)
do while (.not. Sorted(list))
write(*, "(a)", advance="no") "How many numbers from the left do you want to reverse? : "
attempts = attempts + 1
list(1:pos) = list(pos:1:-1)
write(*, "(9i5)") list
write(*,*)
end do
write(*,*)
write(*, "(a,i0,a)") "Congratulations! Solved in ", attempts, " attempts"

contains

subroutine Shuffle(a)
integer, intent(inout) :: a(:)
integer :: i, randpos, temp
real :: r

do i = size(a), 2, -1
call random_number(r)
randpos = int(r * i) + 1
temp = a(randpos)
a(randpos) = a(i)
a(i) = temp
end do
end subroutine

function Sorted(a)
logical :: Sorted
integer, intent(in) :: a(:)
integer :: i

do i = 1, size(a)-1
if(list(i+1) /= list(i)+1) then
Sorted = .false.
return
end if
end do
Sorted = .true.
end function

end program
```

## Go

```package main

import (
"fmt"
"math/rand"
"sort"
"time"
)

func main() {
rand.Seed(time.Now().UnixNano())
var k []int
for {
k = rand.Perm(9)
for i, r := range k {
if r == 0 {
k[i] = 9
}
}
if !sort.IntsAreSorted(k) {
break
}
}
fmt.Println("Sort digits by reversing a number of digits on the left.")
var n, score int
for {
fmt.Print("Digits: ", k, ". How many to reverse? ")
i, _ := fmt.Scanln(&n)
score++
if i == 0 || n < 2 || n > 9 {
fmt.Println("\n(Enter a number from 2 to 9)")
continue
}
for l, r := 0, n-1; l < r; l, r = l+1, r-1 {
k[l], k[r] = k[r], k[l]
}
if sort.IntsAreSorted(k) {
fmt.Print("Digits: ", k, ".\n")
fmt.Print("Your score: ", score, ".  Good job.\n")
return
}
}
}
```

## Groovy

```sorted = [*(1..9)]
arr    = sorted.clone()

void flipstart(n) { arr[0..<n] = arr[0..<n].reverse() }

int steps = 0
while (arr==sorted) Collections.shuffle(arr)
while (arr!=sorted) {
println arr.join(' ')
print 'Reverse how many? '
flipstart( flipcount.toInteger() )
steps += 1
}
println "Done! That took you \${steps} steps"
```

```import Data.List
import Control.Arrow
import Rosetta.Knuthshuffle

numberRevGame = do
let goal = [1..9]

shuffle xs =
if xs /= goal then return xs
else shuffle =<< knuthShuffle xs

prefixFlipAt k = uncurry (++). first reverse. splitAt k

prompt r ry = do
putStr \$ show r ++ ". " ++ concatMap (flip (++) " ". show) ry
++ " How many to flip? "
answ <- getLine
if n<10 && 0<n then return n
else do
putStrLn "Error. The number should be between 0 and 10. Try again"
prompt r ry

playNRG r nrs =
if nrs == goal then do
putStrLn \$ "The answer is: " ++ concatMap (flip (++) " ". show) nrs
putStrLn \$ "It took you " ++ show r ++ " attempts to sort the numbers."
putStrLn ""
else do
answ <- prompt r nrs
playNRG (succ r) (prefixFlipAt answ nrs)

start <- shuffle goal

playNRG 1 start
```

Play:

```*Main> numberRevGame
1. 3 5 1 4 7 6 8 2 9  How many to flip? 7
2. 8 6 7 4 1 5 3 2 9  How many to flip? 8
3. 2 3 5 1 4 7 6 8 9  How many to flip? 3
4. 5 3 2 1 4 7 6 8 9  How many to flip? 6
5. 7 4 1 2 3 5 6 8 9  How many to flip? 7
6. 6 5 3 2 1 4 7 8 9  How many to flip? 6
7. 4 1 2 3 5 6 7 8 9  How many to flip? 4
8. 3 2 1 4 5 6 7 8 9  How many to flip? 3
The answer is: 1 2 3 4 5 6 7 8 9
It took you 9 attempts to sort the numbers.
```

## HicEst

```   WRITE(Messagebox) "You took ", Reversals(), " attempts"

FUNCTION Reversals()
DIMENSION digits(9), temp(9)

digits = 0
DO i = 1, 9 ! create the shuffled digits
1   x = CEILING( RAN(9) )
IF( INDEX(digits, x) ) GOTO 1 ! HicEst has no WHILE
digits(i) = x
ENDDO

DO Reversals = 1, 1E6 ! HicEst needs an upper bound
DLG(NameEdit=Flips, DNum, MIn=0, MAx=9, Text=digits)
DO j = 1, Flips/2
swap = digits(j)
digits(j) = digits(Flips+1-j)
digits(Flips+1-j) = swap
ENDDO
temp = digits(\$+1) > digits(\$) ! \$ = left side index
IF( SUM(temp) == 8 ) RETURN
ENDDO
END
```

```procedure main(cq)                                             # Number Reversal Game
local x,nums,R,flips

put(cq,"game")                                                 # start command queue - use command line
rule := string(&digits--'0')                                   # ruler and move commands
every put(protected := [], map(!PROTECT))                      # protected commands
every put(magic := [], !MAGIC)

while x := get(cq) | "MOVE" do {                               # command from queue or ask for move
case x of {
"help" | "h" | "?" :                                     # --- start of user facing commands ---
write("Input a position.  The list will be flipped left to right at that point.\n",
"You win when the list is sorted.\n",
"Commands:\n",
"   help, h, ? - shows this\n",
"   new, g     - new game\n",
"   ruler, r   - shows a ruler\n",
"   show, s    - shows the list\n",
"   <n>        - flips the list at ruler position n\n",
"   quit, q    - quit\n",
"and various magic words.\n"
) & put(cq,"rule")
"game" | "g" | "new"  : {
put(cq,"help")
flips := 0
nums := rule
until nums ~== rule do
every !nums :=: ?nums                                 # shuffle
}
"rule" | "ruler" | "r" :
put(cq,"show") & every writes(" " || " " | !(if /mirror then rule else reverse(rule)) | "\n")
"show" | "s" :
every writes(" " || "=" | !nums | " =\n")
!rule : {                                                #  0 - 9 for flipping
if /mirror then nums[1+:x] := reverse(nums[1+:x])
else nums[0-:x] := reverse(nums[0-:x])
flips +:= 1
put(cq,if nums == rule then "WIN" else "show")
}
"quit" | "q" :
break write("Goodbye.")
!magic:                                                  # --- start of magic
write("That has no power here.  Try again!")
"magic" | "mirror" | "m" : {
mirror := if /mirror then 1 else &null
write("Wait! What is this? The writing has reversed.")
}
!protected:                                              # --- Start of internal (upper case) and protected commands
put(cq,?rule) & write("Tisk, Tisk, don't try and cheat.  Take a random penalty flip!")
"MOVE" :
"WIN" :
put(cq,"ASK") & write("Congratulations you won in ",flips," flips!")
put(cq,case ask("Play another game? : ") of { "y"|"yes" : "game"; "n"|"no" : "quit"; default : "ASK" } )
default:                                                 # --- say what?
write("Sorry I don't know that command, try help?")
}
}
end

procedure ask(s)                       #: ask for input with prompt s and return the 1st word in lower case
writes(\s)
end

```

Sample output:

```Input a position.  The list will be flipped left to right at that point.
You win when the list is sorted.
Commands:
help, h, ? - shows this
new, g     - new game
ruler, r   - shows a ruler
show, s    - shows the list
<n>        - flips the list at ruler position n
quit, q    - quit
and various magic words.

123456789
=745361289 =
Command? : 7
=216354789 =
Command? : 3
=612354789 =
Command? : 6
=453216789 =
Command? : 2
=543216789 =
Command? : 5
Congratulations you won in 5 flips!
Play another game? :
```

## Inform 7

```Number Reversal Game is a room.

The current list is a list of numbers that varies.

When play begins:
now the current list is a shuffled list from 1 to 9;
now the command prompt is "Current list: [current list in brace notation].[line break]How many items to flip? ".

Definition: a list of numbers (called L) is sorted:
repeat with N running from 1 to the number of entries in L:
if entry N in L is not N, no;
yes.

To decide which list of numbers is a shuffled list from (min - number) to (max - number):
let result be a list of numbers;
repeat with N running from min to max:
while true is true:
sort result in random order;
if result is not sorted, decide on result.

Flipping is an action applying to one number. Understand "[number]" as flipping.

Carry out flipping:
let N be the number understood;
let L be the current list;
truncate the current list to the first N entries;
reverse the current list;
truncate L to the last (number of entries in L minus N) entries;
add L to the current list.

Report flipping: say "".

Every turn:
if the current list is sorted, end the story saying "You have won".

This is the new print final score rule:
say "It took you [turn count] flip[s] to sort the list."

The new print final score rule is listed instead of the print final score rule in the for printing the player's obituary rules.
```

## Io

```withRange := method( a, z,
Range clone setRange(a,z)
)
sorted := withRange(1,9) asList
numbers := sorted clone shuffle
while( numbers==sorted, numbers = numbers shuffle)

steps :=0
stdin := File standardInput
while( numbers != sorted,
writeln(numbers join(" "))
write("Reverse how many? ")
withRange(0, ((flipcount-1)/2) floor) foreach( i,
numbers swapIndices(i,flipcount-1-i)
)
steps = steps+1
)
writeln("Done! That took you ", steps, " steps")
```

## J

'''Solution:'''

```require 'misc'                      NB. for the verb prompt

INTRO=: noun define
Number Reversal Game
Flip groups of numbers from the left of the list until
the numbers are sorted in ascending order.
)

reversegame=: verb define
whilst. (-: /:~)nums do.
nums=. 1+9?9                    NB. 1-9 in random order
end.
score=. 0
smoutput INTRO                    NB. Display instructions
while. -.(-: /:~)nums do.
score=. 1+ score                NB. increment score
nnum=. 0".prompt (":score),': ',(":nums),' How many numbers to flip?: '
if. 0 = #nnum do. return. end.  NB. exit on ENTER without number
nums=. (C.i.-nnum) C. nums      NB. reverse first nnum numbers
end.
'You took ',(": score), ' attempts to put the numbers in order.'
)
```

'''Example Usage:'''

```   reversegame''
Number Reversal Game
Sort the numbers in ascending order by repeatedly
flipping sets of numbers from the left.

1: 4 7 5 6 9 1 2 8 3 How many numbers to flip?: 5
2: 9 6 5 7 4 1 2 8 3 How many numbers to flip?: 9
3: 3 8 2 1 4 7 5 6 9 How many numbers to flip?: 2
4: 8 3 2 1 4 7 5 6 9 How many numbers to flip?: 8
5: 6 5 7 4 1 2 3 8 9 How many numbers to flip?: 3
6: 7 5 6 4 1 2 3 8 9 How many numbers to flip?: 7
7: 3 2 1 4 6 5 7 8 9 How many numbers to flip?: 5
8: 6 4 1 2 3 5 7 8 9 How many numbers to flip?: 6
9: 5 3 2 1 4 6 7 8 9 How many numbers to flip?: 5
10: 4 1 2 3 5 6 7 8 9 How many numbers to flip?: 4
11: 3 2 1 4 5 6 7 8 9 How many numbers to flip?: 3
You took 11 attempts to put the numbers in order.
```

## Java

```import java.util.List;
import java.util.ArrayList;
import java.util.Scanner;
import java.util.Collections;

public class ReversalGame {
private List<Integer> gameList;

public ReversalGame() {
initialize();
}

public void play() throws Exception {
int i = 0;
int moveCount = 0;
Scanner scanner = new Scanner(System.in);
while (true) {
System.out.println(gameList);
System.out.println("Please enter a index to reverse from 2 to 9. Enter 99 to quit");
i = scanner.nextInt();
if (i == 99) {
break;
}
if (i < 2 || i > 9) {
System.out.println("Invalid input");
} else {
moveCount++;
reverse(i);
if (isSorted()) {
System.out.println("Congratulations you solved this in " + moveCount + " moves!");
break;
}
}

}
scanner.close();
}

private void reverse(int position) {
Collections.reverse(gameList.subList(0, position));
}

private boolean isSorted() {
for (int i=0; i < gameList.size() - 1; ++i) {
if (gameList.get(i).compareTo(gameList.get(i + 1)) > 0) {
return false;
}
}
return true;
}

private void initialize() {
this.gameList = new ArrayList<Integer>(9);
for (int i=1; i < 10; ++i) {
}
while (isSorted()) {
Collections.shuffle(gameList);
}
}

public static void main(String[] args) {
try {
ReversalGame game = new ReversalGame();
game.play();
} catch (Exception e) {
System.out.println(e.getMessage());
e.printStackTrace();
}
}
}
```

## JavaScript

Use `knuth_shuffle()` function from [[Knuth shuffle#JavaScript|here]].

```
<title>Number Reversal Game</title>

<body>
<div id="start"></div>
<div id="progress"></div>
<div id="score"></div>
<script type="text/javascript">
```
```function endGame(progress) {
var scoreId = progress.scoreId,
result = 'You took ' + progress.count + ' attempts to put the digits in order!';
if (progress.abort === true) {
result = 'Game aborted.';
}
document.getElementById(scoreId).innerHTML = result;
}

function reverseFirstN(arr, n) {
var reversed = arr.slice(0, n).reverse();
return reversed.concat(arr.slice(n));
}

function isSorted(arr) {
return arr.slice(0).sort().toString() === arr.toString();
}

function gameLoop(progress) {
if (isSorted(progress.arr)) {
endGame(progress);
} else {
var n = parseInt(window.prompt('How many elements to reverse?', ''), 10);
if (isNaN(n)) {
progress.abort = true;
} else {
progress.arr = reverseFirstN(progress.arr, n);
progress.innerHTML += '<p>' + progress.arr + '</p>';
progress.count += 1;
}
if (progress.abort !== true) {
// allow window to repaint before next guess
setTimeout(function () {
gameLoop(progress);
}, 1);
}
}
}

function knuth_shuffle(a) {
var n = a.length,
r,
temp;
while (n > 1) {
r = Math.floor(n * Math.random());
n -= 1;
temp = a[n];
a[n] = a[r];
a[r] = temp;
}
return a;
}

function playGame(startId, progressId, scoreId) {
var progress = document.getElementById(progressId);
progress.arr = knuth_shuffle([1, 2, 3, 4, 5, 6, 7, 8, 9]);
document.getElementById(startId).innerHTML = '<p>' + progress.arr.toString() + '</p>';

progress.count = 0;
progress.scoreId = scoreId;

// allow window to repaint before prompting for a guess
setTimeout(function () {
gameLoop(progress);
}, 1);
}

playGame('start', 'progress', 'score');
```
```
</body>
</html>
```

## jq

```# Input: the initial array
def play:
def sorted: . == sort;

def reverse(n):  (.[0:n] | reverse)  + .[n:];

def prompt: "List: \(.list)\nEnter a pivot number: ";

def report: "Great! Your score is \(.score)";

{list: ., score: 0}
| (if .list | sorted then "List was sorted to begin with."
else
prompt,
( label \$done
| foreach inputs as \$n (.;
.list |= reverse(\$n) | .score +=1;
if .list | sorted then report, break \$done else prompt end ))
end);
```

'''Example'''

```[1,2,3,9,8,7,6,5,4] | play
```

'''Transcript'''

```\$ jq -r -n -f play.jq
List: [1,2,3,9,8,7,6,5,4]
Enter a pivot number:
9
List: [4,5,6,7,8,9,3,2,1]
Enter a pivot number:
6
List: [9,8,7,6,5,4,3,2,1]
Enter a pivot number:
9
```

## Julia

```# v0.6

function numrevgame()
l = collect(1:9)
while issorted(l) shuffle!(l) end
score = 0
println("# Number reversal game")
while !issorted(l)
print("\$l\nInsert the index up to which to revert: ")
reverse!(l, 1, n)
score += 1
end
println("\$l... You won!\nScore: \$score")
return score
end

numrevgame()
```

## Kotlin

```// version 1.1.2

fun isAscending(a: IntArray): Boolean {
for (i in 0..8) if (a[i] != i + 1) return false
return true
}

fun main(args: Array<String>) {
val r = java.util.Random()
var count = 0
val numbers = IntArray(9)
numbers = 2 + r.nextInt(8) // this will ensure list isn't ascending
for (i in 1..8) {
var rn: Int
do {
rn = 1 + r.nextInt(9)
} while (rn in numbers)
numbers[i] = rn
}
println("Here's your first list : \${numbers.joinToString()}")
while (true) {
var rev: Int
do {
print("How many numbers from the left are to be reversed : ")
} while (rev !in 2..9)
count++
var i = 0
var j = rev - 1
while (i < j) {
val temp = numbers[i]
numbers[i++] = numbers[j]
numbers[j--] = temp
}
if (isAscending(numbers)) {
println("Here's your final list : \${numbers.joinToString()}")
break
}
println("Here's your list now   : \${numbers.joinToString()}")
}
println("So you've completed the game with a score of \$count")
}
```

Sample game: {{out}}

```
Here's your first list : 4, 3, 2, 7, 1, 6, 5, 8, 9
How many numbers from the left are to be reversed : 4
Here's your list now   : 7, 2, 3, 4, 1, 6, 5, 8, 9
How many numbers from the left are to be reversed : 7
Here's your list now   : 5, 6, 1, 4, 3, 2, 7, 8, 9
How many numbers from the left are to be reversed : 2
Here's your list now   : 6, 5, 1, 4, 3, 2, 7, 8, 9
How many numbers from the left are to be reversed : 6
Here's your list now   : 2, 3, 4, 1, 5, 6, 7, 8, 9
How many numbers from the left are to be reversed : 3
Here's your list now   : 4, 3, 2, 1, 5, 6, 7, 8, 9
How many numbers from the left are to be reversed : 4
Here's your final list : 1, 2, 3, 4, 5, 6, 7, 8, 9
So you've completed the game with a score of 6

```

## Lua

```-- Initialisation
math.randomseed(os.time())
numList = {values = {}}

-- Check whether list contains n
function numList:contains (n)
for k, v in pairs(self.values) do
if v == n then return true end
end
return false
end

-- Check whether list is in order
function numList:inOrder ()
for k, v in pairs(self.values) do
if k ~=v then return false end
end
return true
end

-- Create necessarily out-of-order list
function numList:build ()
local newNum
repeat
for i = 1, 9 do
repeat
newNum = math.random(1, 9)
until not numList:contains(newNum)
table.insert(self.values, newNum)
end
until not numList:inOrder()
end

-- Display list of numbers on one line
function numList:show ()
for k, v in pairs(self.values) do
io.write(v .. " ")
end
io.write(":\t")
end

-- Reverse n values from left
function numList:reverse (n)
local swapList = {}
for k, v in pairs(self.values) do
table.insert(swapList, v)
end
for i = 1, n do
swapList[i] = self.values[n + 1 - i]
end
self.values = swapList
end

-- Main procedure
local score = 0
print("\nRosetta Code Number Reversal Game in Lua")
print("
### ==================================
\n")
numList:build()
repeat
numList:show()
score = score + 1
until numList:inOrder()
numList:show()
print("\n\nW00t!  You scored:", score)
```

## M2000 Interpreter

Using stack of values which we can move easy values. When we call subs and pass arguments that arguments as values stored to same stack, but because we pop them (read to variables) we leave stack with 9 values for the game.

To check if we have all values in order, we just check the difference of two items one after the other, if is one, and if not one then we leave checking returning false.

Sub CheckStack get a value by reference. Because stack of values always get values, a reference is a copy of a weak reference, so in CheckStack a new variable defined as local ok, and get the reference from weak reference in stack. When a sub exit any new,including local variables removed (deleted). Subs are always local to Module, and have same scope as module scope.

To display the values of stack we use Stack statement with no arguments.

```
Module Number_Reversal_Game {
PRINT "Given a jumbled list of the numbers 1 to 9,"
PRINT "you must select how many digits from the left to reverse."
PRINT "Your goal is to get the digits in order with 1 on the left and 9 on the right."
\\ work on a new stack - old stack parked, and attached at the exit of this block
Stack New {
Data 1,2,3,4,5,6,7,8,9
\\ Create jumbled list
For i=1 to 30: Reverse(Random(2,9)):Next i
Tries=0
fin=false
Repeat {
\\ Show Stack
Stack
Try ok {
INPUT " -- How many numbers should be flipped:", flp%
}
if not Ok then print: Restart
if flp%<2 or flp%>9 then Restart
Reverse(flp%)
Tries++
CheckStack(&fin)
} until Fin
\\ show stack again
Stack
PRINT "You took "; tries; " tries to put the digits in order."
}
Sub Reverse(n)
Shift 1, -n       ' shift one item nth times in reverse
End Sub
Sub CheckStack(&ok)
ok=true
if stack.size<2 then exit sub
Local i
For i=2 to stack.size {
ok=stackitem(i)-stackitem(i-1)=1
if ok else exit
}
End Sub
}
Number_Reversal_Game

```

## Mathematica

Module[{array = Range@9, score = 0}, While[array == Range@9, array = RandomSample@Range@9]; While[array != Range@9, Print@array; (array[[;; #]] = Reverse@array[[;; #]]) &@ Input["How many digits would you like to reverse?"]; score++]; Print@array; Print["Your score:", score]]

```

## MATLAB

```MATLAB
function NumberReversalGame
list = randperm(9);
while issorted(list)
list = randperm(9);
end
fprintf('Given a list of numbers, try to put them into ascending order\n')
fprintf('by sequentially reversing everything left of a point you choose\n')
fprintf('in the array. Try to do it in as few reversals as possible.\n')
fprintf('No input will quit the game.\n')
fprintf('Position Num:%s\n', sprintf(' %d', 1:length(list)))
fprintf('Current List:%s', sprintf(' %d', list))
pivot = 1;
nTries = 0;
while ~isempty(pivot) && ~issorted(list)
pivot = input('    Enter position of reversal limit: ');
if pivot
list(1:pivot) = list(pivot:-1:1);
fprintf('Current List:%s', sprintf(' %d', list))
nTries = nTries+1;
end
end
if issorted(list)
fprintf('\nCongratulations! You win! Only %d reversals.\n', nTries)
else
fprintf('\nPlay again soon!\n')
end
end
```

{{out}}

```Given a list of numbers, try to put them into ascending order
by sequentially reversing everything left of a point you choose
in the array. Try to do it in as few reversals as possible.
No input will quit the game.
Position Num: 1 2 3 4 5 6 7 8 9
Current List: 1 6 3 2 8 7 9 4 5    Enter position of reversal limit: 7
Current List: 9 7 8 2 3 6 1 4 5    Enter position of reversal limit: 9
Current List: 5 4 1 6 3 2 8 7 9    Enter position of reversal limit: 7
Current List: 8 2 3 6 1 4 5 7 9    Enter position of reversal limit: 8
Current List: 7 5 4 1 6 3 2 8 9    Enter position of reversal limit: 7
Current List: 2 3 6 1 4 5 7 8 9    Enter position of reversal limit: 3
Current List: 6 3 2 1 4 5 7 8 9    Enter position of reversal limit: 6
Current List: 5 4 1 2 3 6 7 8 9    Enter position of reversal limit: 5
Current List: 3 2 1 4 5 6 7 8 9    Enter position of reversal limit: 3
Current List: 1 2 3 4 5 6 7 8 9
Congratulations! You win! Only 9 reversals.
```

## Nim

```import math, rdstdin, strutils, algorithm
randomize()

proc shuffle[T](x: var seq[T]) =
for i in countdown(x.high, 0):
let j = random(i + 1)
swap(x[i], x[j])

proc isSorted[T](s: openarray[T]): bool =
var last = low(T)
for c in s:
if c < last:
return false
last = c
return true

proc toString[T](s: openarray[T]): string =
result = ""
for i, x in s:
if i > 0:

echo """number reversal game
Given a jumbled list of the numbers 1 to 9
Show the list.
Ask the player how many digits from the left to reverse.
Reverse those digits then ask again.
until all the digits end up in ascending order."""

var data = @[1,2,3,4,5,6,7,8,9]
var trials = 0
while isSorted data:
shuffle data
while not isSorted data:
inc trials
"#" & \$trials & ": List: '" & toString(data) & "' Flip how many?: ")
reverse(data, 0, flip - 1)

echo "You took ", trials, " attempts to put the digits in order!"
```

Example:

```#1: List: '6 5 8 7 2 1 9 3 4' Flip how many?: 5
#2: List: '2 7 8 5 6 1 9 3 4' Flip how many?: 6
#3: List: '1 6 5 8 7 2 9 3 4' Flip how many?: 9
#4: List: '4 3 9 2 7 8 5 6 1' Flip how many?: 4
#5: List: '2 9 3 4 7 8 5 6 1' Flip how many?: 8
#6: List: '6 5 8 7 4 3 9 2 1' Flip how many?: 6
#7: List: '3 4 7 8 5 6 9 2 1' Flip how many?: 7
#8: List: '9 6 5 8 7 4 3 2 1' Flip how many?: 3
#9: List: '5 6 9 8 7 4 3 2 1' Flip how many?: 5
#10: List: '7 8 9 6 5 4 3 2 1' Flip how many?: 3
#11: List: '9 8 7 6 5 4 3 2 1' Flip how many?: 9
You took 11 attempts to put the digits in order!
```

## OCaml

### Imperative

```let swap ar i j =
let tmp = ar.(i) in
ar.(i) <- ar.(j);
ar.(j) <- tmp

let shuffle ar =
for i = pred(Array.length ar) downto 1 do
let j = Random.int (i + 1) in
swap ar i j
done

let reversal ar n =
for i = 0 to pred(n/2) do
let j = (pred n) - i in
swap ar i j
done

let sorted ar =
try
let prev = ref ar.(0) in
for i = 1 to pred(Array.length ar) do
if ar.(i) < !prev then raise Exit;
prev := ar.(i)
done;
(true)
with Exit ->
(false)

let () =
print_endline "\
Number Reversal Game
Sort the numbers in ascending order by repeatedly
flipping sets of numbers from the left.";
Random.self_init();
let nums = Array.init 9 (fun i -> succ i) in
while sorted nums do shuffle nums done;
let n = ref 1 in
while not(sorted nums) do
Printf.printf "#%2d: " !n;
Array.iter (Printf.printf " %d") nums;
print_newline();
reversal nums r;
incr n;
done;
print_endline "Congratulations!";
Printf.printf "You took %d attempts to put the digits in order.\n" !n;
;;
```

### Functional

```let revert li n =
let rec aux acc i = function
| [] -> acc
| xs when i <= 0 -> acc @ xs
| x::xs -> aux (x::acc) (pred i) xs
in
aux [] n li

let take li n =
let rec aux acc i = function
| x::xs when i = n -> (x, List.rev_append acc xs)
| x::xs -> aux (x::acc) (succ i) xs
| _ -> invalid_arg "take"
in
aux [] 0 li

let shuffle li =
let rec aux acc len = function
| [] -> acc
| li ->
let x, xs = take li (Random.int len) in
aux (x::acc) (pred len) xs
in
aux [] (List.length li) li

let rec sorted = function
| [] -> (true)
| x::y::_ when x > y -> (false)
| x::xs -> sorted xs

let () =
print_endline "\
Number Reversal Game
Sort the numbers in ascending order by repeatedly
flipping sets of numbers from the left.";
Random.self_init();
let li = shuffle [1; 2; 3; 4; 5; 6; 7; 8; 9] in
let rec loop n li =
Printf.printf "#%2d: " n;
List.iter (Printf.printf " %d") li;
Printf.printf "  ? %!";
let li = revert li r in
if not(sorted li)
then loop (succ n) li
else Printf.printf "You took %d attempts to put the digits in order.\n" n;
in
loop 1 li
;;
```

## Oforth

```import: console

: reversalGame
| l n |
doWhile: [
ListBuffer new ->l
while(l size 9 <>) [ 9 rand dup l include ifFalse: [ l add ] else: [ drop ] ]
l sort l ==
]

0 while(l sort l <>) [
System.Out "List is " << l << " ==> how many digits from left to reverse : " <-
System.Console askln asInteger dup ifNull: [ drop continue ] ->n
1+ l left(n) reverse l right(l size n -) + ->l
]
"You won ! Your score is :" . println ;
```

{{out}}

```
>reversalGame
List is [9, 1, 3, 6, 5, 7, 8, 4, 2] ==> how many digits from left to reverse : 9
List is [2, 4, 8, 7, 5, 6, 3, 1, 9] ==> how many digits from left to reverse : 3
List is [8, 4, 2, 7, 5, 6, 3, 1, 9] ==> how many digits from left to reverse : 8
List is [1, 3, 6, 5, 7, 2, 4, 8, 9] ==> how many digits from left to reverse : 5
List is [7, 5, 6, 3, 1, 2, 4, 8, 9] ==> how many digits from left to reverse : 7
List is [4, 2, 1, 3, 6, 5, 7, 8, 9] ==> how many digits from left to reverse : 5
List is [6, 3, 1, 2, 4, 5, 7, 8, 9] ==> how many digits from left to reverse : 6
List is [5, 4, 2, 1, 3, 6, 7, 8, 9] ==> how many digits from left to reverse : 5
List is [3, 1, 2, 4, 5, 6, 7, 8, 9] ==> how many digits from left to reverse : 3
List is [2, 1, 3, 4, 5, 6, 7, 8, 9] ==> how many digits from left to reverse : 2
You won ! Your score is : 10

```

## Oz

```declare
proc {Main}
proc {Loop N Xs}
if {Not {IsSorted Xs}} then
Num NewXs
in
{System.printInfo N#": "}
{System.print Xs}
{System.printInfo " -- Reverse how many? "}
NewXs = {Append
{Reverse {List.take Xs Num}}
{List.drop Xs Num}}
{Loop N+1 NewXs}
else
{System.showInfo "You took "#N#" tries to put the digits in order."}
end
end
fun {EnsureShuffled Xs}
Ys = {Shuffle Xs}
in
if {Not {IsSorted Ys}} then Ys
else {EnsureShuffled Xs}
end
end
in
{Loop 0 {EnsureShuffled {List.number 1 9 1}}}
end

fun {IsSorted Xs}
{Sort Xs Value.'<'} == Xs
end

local
class TextFile from Open.file Open.text end
StdIn = {New TextFile init(name:stdin)}
in
{StdIn getS(\$)}
end
end

fun {Shuffle Xs}
{FoldL Xs
fun {\$ Z _}
{Pick {Diff Xs Z}}|Z
end
nil}
end

fun {Pick Xs}
{Nth Xs {OS.rand} mod {Length Xs} + 1}
end

fun {Diff Xs Ys}
{FoldL Ys List.subtract Xs}
end
in
{Main}
```

## PARI/GP

```game()={
my(v=numtoperm(9,random(9!-1)),score,in,t); \\ Create vector with 1..9, excluding the one sorted in ascending order
while(v!=vecsort(v),
print(concat(concat([""],v)));
in=input();
for(i=0,in\2-1,
t=v[9-i];
v[9-i]=v[10-in+i];
v[10-in+i]=t
);
score++
);
score
};
```

## Perl

```use List::Util qw(shuffle);

my \$turn = 0;
my @jumble = shuffle 1..9;

while ( join('', @jumble) eq '123456789' ) {
@jumble = shuffle 1..9;
}

until ( join('', @jumble) eq '123456789' ) {
\$turn++;
printf "%2d: @jumble - Flip how many digits ? ", \$turn;

my \$d = <>;

@jumble[0..\$d-1] = reverse @jumble[0..\$d-1];
}

print "    @jumble\n";
print "You won in \$turn turns.\n";
```

Output:

``` 1: 9 8 2 5 1 7 6 3 4 - Flip how many digits ? 9
2: 4 3 6 7 1 5 2 8 9 - Flip how many digits ? 4
3: 7 6 3 4 1 5 2 8 9 - Flip how many digits ? 7
4: 2 5 1 4 3 6 7 8 9 - Flip how many digits ? 2
5: 5 2 1 4 3 6 7 8 9 - Flip how many digits ? 5
6: 3 4 1 2 5 6 7 8 9 - Flip how many digits ? 2
7: 4 3 1 2 5 6 7 8 9 - Flip how many digits ? 4
8: 2 1 3 4 5 6 7 8 9 - Flip how many digits ? 2
1 2 3 4 5 6 7 8 9
You won in 8 turns.
```

## Perl 6

Do-at-least-once loops are fairly rare, but this program wants to have two of them. We use the built-in .pick(*) method to shuffle the numbers. We use .= to dispatch a mutating method in two spots; the first is just a different way to write ++, while the second of these reverses an array slice in place. The [<] is a reduction operator on less than, so it returns true if the elements of the list are strictly ordered. We also see in the first repeat loop that, although the while condition is not tested till after the loop, the while condition can in fact declare the variable that will be initialized the first time through the loop, which is a neat trick, and not half unreadable once you get used to it.

```repeat while [<] my @jumbled-list {
@jumbled-list = (1..9).pick(*)
}

my \$turn = 0;
repeat until [<] @jumbled-list {
my \$d = prompt \$turn.=succ.fmt('%2d: ') ~
@jumbled-list ~
" - Flip how many digits? "
or exit;
@jumbled-list[^\$d] .= reverse;
}

say "    @jumbled-list[]";
say "You won in \$turn turns.";
```

Output:

``` 1: 3 5 8 2 7 9 6 1 4 - Flip how many digits ? 6
2: 9 7 2 8 5 3 6 1 4 - Flip how many digits ? 9
3: 4 1 6 3 5 8 2 7 9 - Flip how many digits ? 6
4: 8 5 3 6 1 4 2 7 9 - Flip how many digits ? 8
5: 7 2 4 1 6 3 5 8 9 - Flip how many digits ? 7
6: 5 3 6 1 4 2 7 8 9 - Flip how many digits ? 3
7: 6 3 5 1 4 2 7 8 9 - Flip how many digits ? 6
8: 2 4 1 5 3 6 7 8 9 - Flip how many digits ? 4
9: 5 1 4 2 3 6 7 8 9 - Flip how many digits ? 5
10: 3 2 4 1 5 6 7 8 9 - Flip how many digits ? 3
11: 4 2 3 1 5 6 7 8 9 - Flip how many digits ? 4
12: 1 3 2 4 5 6 7 8 9 - Flip how many digits ? 2
13: 3 1 2 4 5 6 7 8 9 - Flip how many digits ? 3
14: 2 1 3 4 5 6 7 8 9 - Flip how many digits ? 2
1 2 3 4 5 6 7 8 9
You won in 14 turns.
```

## Phix

Simplified copy of [[Number_reversal_game#Euphoria|Euphoria]]

```puts(1,"Given a jumbled list of the numbers 1 to 9,\n")
puts(1,"you must select how many digits from the left to reverse.\n")
puts(1,"Your goal is to get the digits in order with 1 on the left and 9 on the right.\n")

constant inums = tagset(9)
sequence nums
integer turns = 0, flip

while 1 do
nums = shuffle(inums)
if nums!=inums then exit end if
end while

while 1 do
printf(1,"%2d : %d %d %d %d %d %d %d %d %d ",turns&nums)
if nums=inums then exit end if
flip = prompt_number(" -- How many numbers should be flipped? ",{1,9})
nums[1..flip] = reverse(nums[1..flip])
turns += 1
end while

printf(1,"\nYou took %d turns to put the digits in order.", turns)
```

{{out}}

```Given a jumbled list of the numbers 1 to 9,
you must select how many digits from the left to reverse.
Your goal is to get the digits in order with 1 on the left and 9 on the right.
0 : 3 7 8 1 6 2 5 4 9  -- How many numbers should be flipped? 3
1 : 8 7 3 1 6 2 5 4 9  -- How many numbers should be flipped? 8
2 : 4 5 2 6 1 3 7 8 9  -- How many numbers should be flipped? 4
3 : 6 2 5 4 1 3 7 8 9  -- How many numbers should be flipped? 6
4 : 3 1 4 5 2 6 7 8 9  -- How many numbers should be flipped? 4
5 : 5 4 1 3 2 6 7 8 9  -- How many numbers should be flipped? 5
6 : 2 3 1 4 5 6 7 8 9  -- How many numbers should be flipped? 2
7 : 3 2 1 4 5 6 7 8 9  -- How many numbers should be flipped? 3
8 : 1 2 3 4 5 6 7 8 9
You took 8 turns to put the digits in order.

```

## PHP

```PHP
class ReversalGame {
private \$numbers;

public function __construct() {
\$this->initialize();
}

public function play() {
\$i = 0;
\$moveCount = 0;
while (true) {
echo json_encode(\$this->numbers) . "\n";
echo "Please enter an index to reverse from 2 to 9. Enter 99 to quit\n";
\$i = intval(rtrim(fgets(STDIN), "\n"));
if (\$i == 99) {
break;
}
if (\$i < 2 || \$i > 9) {
echo "Invalid input\n";
} else {
\$moveCount++;
\$this->reverse(\$i);
if (\$this->isSorted()) {
echo "Congratulations you solved this in \$moveCount moves!\n";
break;
}
}

}
}

private function reverse(\$position) {
array_splice(\$this->numbers, 0, \$position, array_reverse(array_slice(\$this->numbers, 0, \$position)));
}

private function isSorted() {
for (\$i = 0; \$i < count(\$this->numbers) - 1; ++\$i) {
if (\$this->numbers[\$i] > \$this->numbers[\$i + 1]) {
return false;
}
}
return true;
}

private function initialize() {
\$this->numbers = range(1, 9);
while (\$this->isSorted()) {
shuffle(\$this->numbers);
}
}

}

\$game = new ReversalGame();
\$game->play();

```

## PicoLisp

```PicoLisp

(de reversalGame ()
(let (Lst (shuffle (range 1 9))  Cnt 0)
(while (apply < Lst)
(setq Lst (shuffle Lst)) )
(loop
(printsp Lst)
(T (apply < Lst) Cnt)
(setq Lst (flip Lst @))
(inc 'Cnt) ) ) )
```

Output:

```txt
: (reversalGame)
(1 7 6 8 4 2 3 5 9) 4
(8 6 7 1 4 2 3 5 9) 8
(5 3 2 4 1 7 6 8 9) 6
(7 1 4 2 3 5 6 8 9) 7
(6 5 3 2 4 1 7 8 9) 6
(1 4 2 3 5 6 7 8 9) 2
(4 1 2 3 5 6 7 8 9) 4
(3 2 1 4 5 6 7 8 9) 3
(1 2 3 4 5 6 7 8 9) -> 8
```

## PL/I

```PL/I

digits: procedure options (main); /* 23 April 2010 */
declare s character (9) varying;
declare i fixed binary;
declare digit character (1);

restart:
put skip list ('In this game, you are given a group of digits.');
put skip list ('You will specify one of those digits.');
put skip list ('The computer will then reverse the digits up to the one you nominate.');
put skip list ('Your task is to repeat this process a number of times until all the digits');
put skip list ('are in order, left to right, 1 to 9.');
put skip list ('Here are your digits');

redo:
s = '';
do until (length(s) = 9);
digit = trim ( fixed(trunc (1+random()*9) ) );
if index(s, digit) = 0 then s = s || digit;
end;
if s = '123456789' then go to redo;

loop:
do forever;
put skip list (s);
if s = '123456789' then leave;
get edit (digit) (a(1));
i = index(s, digit);
if i = 0 then do; put skip list ('invalid request'); iterate loop; end;
s = reverse( substr(s, 1, i) ) || substr(s, i+1, length(s)-i);
end;
put skip list ('Congratulations');
go to restart;
end digits;

```

## PowerShell

```PowerShell

#adding the below function to the previous users submission to prevent the small
#chance of getting an array that is in ascending order.

#Full disclosure: I am an infrastructure engineer, not a dev. My code is likely

function generateArray{
\$fArray = 1..9 | Get-Random -Count 9
if (-join \$fArray -eq -join @(1..9)){
generateArray
}
return \$fArray
}
\$array = generateArray

#everything below is untouched from original submission
\$nTries = 0
While(-join \$Array -ne -join @(1..9)){
\$nTries++
\$nReverse = Read-Host -Prompt "[\$Array] -- How many digits to reverse? "
[Array]::Reverse(\$Array,0,\$nReverse)
}
"\$Array"

```

## PureBasic

```PureBasic
Dim MyList(9)

Declare is_list_sorted()

If OpenConsole()
Define score, indata, i, txt\$

For i=1 To 9         ;- Initiate the list
MyList(i)=i
Next
While is_list_sorted()
For i=1 To 9      ;- Do a Fisher–Yates shuffle
Swap MyList(i), MyList(Random(i)+1)
Next
Wend

;- Start the Game
Repeat
score+1
txt\$=RSet(str(score), 3)+": "      ;- Show current list
For i=1 To 9
txt\$+str(MyList(i))+" "
Next
Repeat                             ;- Get input & swap
Print(txt\$+"| How many numbers should be flipped? "): indata=Val(Input())
Until indata>=1 And indata<=9      ;- Verify the input
For i=1 To (indata/2)
Swap MyList(i),MyList(indata-i+1)
Next
Until is_list_sorted()

;- Present result & wait for users input before closing down
PrintN(#CRLF\$+"You did it in "+str(score)+" moves")
Print("Press ENTER to exit"): Input()
CloseConsole()
EndIf

Procedure is_list_sorted()
Protected i
Shared MyList()
For i=1 To 9
If MyList(i)<>i
ProcedureReturn #False
EndIf
Next
ProcedureReturn #True
EndProcedure
```

## Python

```python
'''
number reversal game
Given a jumbled list of the numbers 1 to 9
Show the list.
Ask the player how many digits from the left to reverse.
Reverse those digits then ask again.
until all the digits end up in ascending order.

'''

import random

print(__doc__)
data, trials = list('123456789'), 0
while data == sorted(data):
random.shuffle(data)
while data != sorted(data):
trials += 1
flip = int(input('#%2i: LIST: %r Flip how many?: ' % (trials, ' '.join(data))))
data[:flip] = reversed(data[:flip])

print('\nYou took %2i attempts to put the digits in order!' % trials)
```

'''Sample output:'''

```txt

number reversal game
Given a jumbled list of the numbers 1 to 9
Show the list.
Ask the player how many digits from the left to reverse.
Reverse those digits then ask again.
until all the digits end up in ascending order.

# 1: LIST: '1 3 9 2 7 5 4 8 6' Flip how many?: 9
# 2: LIST: '6 8 4 5 7 2 9 3 1' Flip how many?: 6
# 3: LIST: '2 7 5 4 8 6 9 3 1' Flip how many?: 8
# 4: LIST: '3 9 6 8 4 5 7 2 1' Flip how many?: 7
# 5: LIST: '7 5 4 8 6 9 3 2 1' Flip how many?: 3
# 6: LIST: '4 5 7 8 6 9 3 2 1' Flip how many?: 6
# 7: LIST: '9 6 8 7 5 4 3 2 1' Flip how many?: 2
# 8: LIST: '6 9 8 7 5 4 3 2 1' Flip how many?: 4
# 9: LIST: '7 8 9 6 5 4 3 2 1' Flip how many?: 3
#10: LIST: '9 8 7 6 5 4 3 2 1' Flip how many?: 9

You took 10 attempts to put the digits in order!
```

## R

reversalGame <- function(){
cat("Welcome to the Number Reversal Game! \n")
cat("Sort the numbers into ascending order by repeatedly \n",
"reversing the first n digits, where you specify n. \n \n", sep="")

# Generate a list that's definitely not in ascending order, per instuctions
data <- sample(1:9, 9)
while (all(data == 1:9)){
cat("What were the chances...? \n")
data <- sample(1:9, 9)
}
trials <- 0

# Play the game
while (any(data != 1:9)){
trials <- trials + 1
cat("Trial", sprintf("%02d", trials), " # ", data, " #  ")
}

# Victory!
cat("Well done.  You needed", trials, "flips. \n")
}
```

Sample output:
>reversalGame()
Welcome to the Number Reversal Game!
Sort the numbers into ascending order by repeatedly
reversing the first n digits, where you specify n.

Trial 01  #  4 3 2 1 7 9 8 5 6  #  Flip how many? 7
Trial 02  #  8 9 7 1 2 3 4 5 6  #  Flip how many? 2
Trial 03  #  9 8 7 1 2 3 4 5 6  #  Flip how many? 9
Trial 04  #  6 5 4 3 2 1 7 8 9  #  Flip how many? 6
Well done.  You needed 4 flips.
```

## Racket

```Racket
#lang racket
(let loop ([nums (range 1 10)] [n 0])
(cond [(apply < nums) (if (zero? n)
(loop (shuffle nums) 0)
(printf "Done in ~s steps.\n" n))]
[else (printf "Step #~s: ~s\nFlip how many? " n nums)
(define-values (l r) (split-at nums (read)))
(loop (append (reverse l) r) (add1 n))]))
```

## Rascal

```Rascal
import Prelude;
import vis::Figure;
import vis::Render;

public void NumberReversalGame(){

//generate randomlist
L = [1..9];
score = 0;
randomlist = [];
while (L != []){
temp = takeOneFrom(L);
randomlist += temp;
L = temp;
}

// user interaction
score = 0;
text1 = "";
figure =
box(vcat([
box(text(str(){
return "";})),
box(textfield("Insert number of digits you would like to reverse here.",
void(str s){
score += 1;
n = toInt(s);
spliced = slice(randomlist, 0, n);
randomlist = reverse(spliced) + (randomlist - spliced);
},
fillColor("lightblue"))),
box(text(str(){
return ((randomlist == [1 .. 9]) ? "Well done! Your score: ." : "Keep going!");}))
]));

render(figure);
}
```

Output:

[[File:NRG3.jpg]]

## REBOL

```REBOL
REBOL []

print "NUMBER REVERSAL GAME"

tries: 0
goal: [1 2 3 4 5 6 7 8 9]
random/seed now

until [
jumble: random goal
jumble != goal ; repeat in the unlikely case that jumble isn't jumbled
]

while [jumble != goal] [
prin jumble
prin " How many to flip? "
flip-index: to-integer input ; no validation!
reverse/part jumble flip-index
tries: tries + 1
]

print rejoin ["You took " tries " attempts."]
```

## REXX

This REXX version:
:::*   displays the game's objective and rules
:::*   validates the input   (must be a single non-zero decimal digit)
:::*   allows the user to enter   '''quit'''
:::*   allows the user to halt the game via   '''Cntl-Break'''   (or equivalent)

```rexx
/*REXX program (a game):  reverse a jumbled set of decimal digits 'til they're in order.*/
signal on halt                                   /*allows the CBLF to  HALT the program.*/
___= copies('─', 9);      pad=left('', 9)        /*a fence used for computer's messages.*/
say ___  "This game will show you nine random unique digits  (1 ──► 9),  and you'll enter"
say ___  "one of those digits  which will reverse all the digits from the left-most digit"
say ___  "up to  (and including)  that decimal digit.  The game's objective is to get all"
say ___  "of the digits in ascending order with the fewest tries.    Here're your digits:"
ok= 123456789                                    /*the result that the string should be.*/
\$=                                               /* ◄─── decimal target to be generated.*/
do  until length(\$)==9;     _=random(1, 9) /*build a random unique numeric string.*/
if pos(_, \$) \== 0  then iterate           /*¬ unique? Only use a decimal dig once*/
\$=\$ || _                                   /*construct a string of unique digits. */
if \$==ok  then \$=                          /*string can't be in order, start over.*/
end   /*until*/

do  score=1  until  \$==ok;           say       /* [↓]  display the digits & the prompt*/
say ___  \$   right('please enter a digit  (or  Quit):', 50)
parse pull ox  .  1  ux . 1  x  .;   upper ux  /*get a decimal digit (maybe) from CBLF*/
if abbrev('QUIT', ux, 1)  then signal halt     /*does the CBLF want to quit this game?*/
if length(x)>1  then do;  say ___ pad '***error***  invalid input:  ' ox;  iterate;  end
if x=''  then  iterate                         /*try again, CBLF didn't enter anything*/
g=pos(x, \$)                                    /*validate if the input digit is legal.*/
if g==0  then say ___ pad '***error***  invalid digit:  '     ox
else \$=strip(reverse(left(\$,g))substr(\$,g+1))  /*reverse some (or all) digits*/
end   /*score*/

say;    say ___  \$;     say;    say center(' Congratulations! ', 70, "═");       say
say ___ pad  'Your score was' score;  exit       /*stick a fork in it,  we're all done. */
halt:  say  ___  pad  'quitting.';     exit      /*  "   "   "   "  "     "    "    "   */
```

{{out|output|text=  from playing one game of the   ''number reversal game'':

```txt

───────── This game will show you nine random unique digits  (1 ──► 9),  and you'll enter
───────── one of those digits  which will reverse all the digits from the left-most digit
───────── up to  (and including)  that decimal digit.  The game's objective is to get all
───────── of the digits in ascending order with the fewest tries.    Here're your digits:

───────── 613279548                  please enter a digit  (or  Quit):
5                    ◄■■■■■■■■■ user input

───────── 597231648                  please enter a digit  (or  Quit):
9                    ◄■■■■■■■■■ user input

───────── 957231648                  please enter a digit  (or  Quit):
8                    ◄■■■■■■■■■ user input

───────── 846132759                  please enter a digit  (or  Quit):
5                    ◄■■■■■■■■■ user input

───────── 572316489                  please enter a digit  (or  Quit):
7                    ◄■■■■■■■■■ user input

───────── 752316489                  please enter a digit  (or  Quit):
4                    ◄■■■■■■■■■ user input

───────── 461325789                  please enter a digit  (or  Quit):
6                    ◄■■■■■■■■■ user input

───────── 641325789                  please enter a digit  (or  Quit):
5                    ◄■■■■■■■■■ user input

───────── 523146789                  please enter a digit  (or  Quit):
4                    ◄■■■■■■■■■ user input

───────── 413256789                  please enter a digit  (or  Quit):
2                    ◄■■■■■■■■■ user input

───────── 231456789                  please enter a digit  (or  Quit):
3                    ◄■■■■■■■■■ user input

───────── 321456789                  please enter a digit  (or  Quit):
1                    ◄■■■■■■■■■ user input

───────── 123456789

══════════════════════════ Congratulations! ══════════════════════════

```

## Ring

```ring

# Project : Number reversal game

rever = 1:9
leftrever = []
for n = 1 to len(rever)
rnd = random(8) + 1
temp = rever[n]
rever[n] = rever[rnd]
rever[rnd] = temp
next
see rever
see nl
while true
num = 0
leftrever = []
showarray(rever)
see " : Reverse how many = "
give r
r = number(r)
for n = 1 to r
next
leftrever = reverse(leftrever)
for pos = 1 to r
rever[pos] = leftrever[pos]
next
for m = 1 to len(rever)
if rever[m] = m
num = num + 1
ok
next
if num = len(rever)
exit
ok
end
see "You took " + num + " attempts." + nl

func swap(a, b)
temp = a
a = b
b = temp
return [a, b]

func showarray(vect)
svect = ""
for n = 1 to len(vect)
svect = svect + vect[n] + " "
next
svect = left(svect, len(svect) - 1)
see svect

```

Output:

```txt

7 2 3 1 5 8 6 4 9 : Reverse how many? 6
8 5 1 3 2 7 6 4 9 : Reverse how many? 8
4 6 7 2 3 1 5 8 9 : Reverse how many? 3
7 6 4 2 3 1 5 8 9 : Reverse how many? 7
5 1 3 2 4 6 7 8 9 : Reverse how many? 5
4 2 3 1 5 6 7 8 9 : Reverse how many? 4
1 3 2 4 5 6 7 8 9 : Reverse how many? 3
2 3 1 4 5 6 7 8 9 : Reverse how many? 2
3 2 1 4 5 6 7 8 9 : Reverse how many? 3
You took 9 attempts.

```

## Ruby

```ruby
ary = (1..9).to_a
ary.shuffle! while ary == ary.sort
score = 0
until ary == ary.sort
print "#{ary.inspect} -- How many digits to reverse? "
num = gets.to_i  # should validate input
ary[0, num] = ary[0, num].reverse
score += 1
end
p ary
```

sample output:

```txt
\$ ruby number_reversal_game.rb
[4, 2, 1, 8, 7, 6, 3, 5, 9] -- How many digits to reverse? 4
[8, 1, 2, 4, 7, 6, 3, 5, 9] -- How many digits to reverse? 8
[5, 3, 6, 7, 4, 2, 1, 8, 9] -- How many digits to reverse? 4
[7, 6, 3, 5, 4, 2, 1, 8, 9] -- How many digits to reverse? 7
[1, 2, 4, 5, 3, 6, 7, 8, 9] -- How many digits to reverse? 4
[5, 4, 2, 1, 3, 6, 7, 8, 9] -- How many digits to reverse? 5
[3, 1, 2, 4, 5, 6, 7, 8, 9] -- How many digits to reverse? 3
[2, 1, 3, 4, 5, 6, 7, 8, 9] -- How many digits to reverse? 2
[1, 2, 3, 4, 5, 6, 7, 8, 9]
```

## Run BASIC

```runbasic
for i = 1 to 9  ' get numbers 1 to 9
n(i) = i
next i
numShuffles = 3
' ----------------------------------
' shuffle numbers
' ----------------------------------
for 	i 	= 1 to 9 * numShuffles
i1	= int(rnd(1)*9) + 1
i2	= int(rnd(1)*9) + 1
h2	= n(i1)
n(i1)	= n(i2)
n(i2)	= h2
next i

for i = 1 to 9
a\$ = a\$ + str\$(n(i)) + " "
next i
count = 0

[loop]
count = count + 1
print count;" : ";a\$
for i = 1 to 9                ' check if in sequence
j = i * 2
if mid\$(a\$,j-1,1) > mid\$(a\$,j,1) then goto [notOrdered]
next i
print "It took ";count;" tries"
end

[notOrdered]
input "How many numbers to flip:";i
i  = ((i-1) * 2) + 1
b\$ = ""
for j = i to 1 step -2
b\$ = b\$ + mid\$(a\$,j,2)
next j
a\$  = b\$ + mid\$(a\$,i + 2)
goto [loop]
end
```

## Scala

```Scala
object NumberReversalGame extends App {
def play(n: Int, cur: List[Int], goal: List[Int]) {
readLine(s"""\$n. \${cur mkString " "}  How many to flip? """) match {
case null => println
case s => scala.util.Try(s.toInt) match {
case scala.util.Success(i) if i > 0 && i <= cur.length =>
(cur.take(i).reverse ++ cur.drop(i)) match {
case done if done == goal =>
println(s"Congratulations! You solved "+goal.mkString(" "))
println(s"Your score is \$n (lower is better)")
case next => play(n + 1, next, goal)
}
case _ => println(s"Choose a number between 1 and \${cur.length}")
play(n + 1, cur, goal)
}
}
}

def play(size: Int) {
val goal = List.range(1, size + 1)
def init: List[Int] = scala.util.Random.shuffle(goal) match {
case repeat if repeat == goal => init
case done => done
}
play(1, init, goal)
}

play(9)
}
```

{{out}}

```txt
1. 8 4 2 9 6 3 7 5 1  How many to flip? 3
2. 2 4 8 9 6 3 7 5 1  How many to flip? 8
3. 5 7 3 6 9 8 4 2 1  How many to flip? 3
4. 3 7 5 6 9 8 4 2 1  How many to flip? 7
5. 4 8 9 6 5 7 3 2 1  How many to flip? 6
6. 7 5 6 9 8 4 3 2 1  How many to flip? 2
7. 5 7 6 9 8 4 3 2 1  How many to flip? 5
8. 8 9 6 7 5 4 3 2 1  How many to flip? 3
9. 6 9 8 7 5 4 3 2 1  How many to flip? 4
10. 7 8 9 6 5 4 3 2 1  How many to flip? 3
11. 9 8 7 6 5 4 3 2 1  How many to flip? 9
Congratulations! You solved 1 2 3 4 5 6 7 8 9
Your score is 11 (lower is better)
```

## Scheme

```scheme

(import (scheme base)
(scheme write)
(srfi 1)   ; list functions
(srfi 27)) ; random numbers

(random-source-randomize! default-random-source)

(define (make-randomised-list)
(let ((vec (apply vector (iota 9 1))))
(do ((c 0 (+ 1 c)))
((and (>= c 20)                            ; at least 20 tries
(not (apply < (vector->list vec)))) ; ensures list not in order
(vector->list vec))
(let* ((i (random-integer 9)) ; swap two randomly chosen elements
(j (random-integer 9))
(tmp (vector-ref vec i)))
(vector-set! vec i (vector-ref vec j))
(vector-set! vec j tmp)))))

(define (play-game lst plays)
(define (reverse-first n lst)
(let-values (((start tail) (split-at lst n)))
(append (reverse start) tail)))
;
(display "List: ") (display lst) (newline)
(display "How many numbers should be flipped? ")
(new-lst (reverse-first flip lst)))
(if (apply < new-lst)
(display (string-append "Finished in "
(number->string plays)
" attempts\n"))
(play-game new-lst (+ 1 plays)))))

(play-game (make-randomised-list) 1)

```

{{out}}

```txt

List: (1 8 3 4 9 2 7 5 6)
How many numbers should be flipped? 5
List: (9 4 3 8 1 2 7 5 6)
How many numbers should be flipped? 9
List: (6 5 7 2 1 8 3 4 9)
How many numbers should be flipped? 6
List: (8 1 2 7 5 6 3 4 9)
How many numbers should be flipped? 8
List: (4 3 6 5 7 2 1 8 9)
How many numbers should be flipped? 5
List: (7 5 6 3 4 2 1 8 9)
How many numbers should be flipped? 7
List: (1 2 4 3 6 5 7 8 9)
How many numbers should be flipped? 5
List: (6 3 4 2 1 5 7 8 9)
How many numbers should be flipped? 6
List: (5 1 2 4 3 6 7 8 9)
How many numbers should be flipped? 5
List: (3 4 2 1 5 6 7 8 9)
How many numbers should be flipped? 2
List: (4 3 2 1 5 6 7 8 9)
How many numbers should be flipped? 4
Finished in 11 attempts

```

## Seed7

```seed7
\$ include "seed7_05.s7i";

const proc: main is func
local
const array integer: sortedList is [] ( 1, 2, 3, 4, 5, 6, 7, 8, 9);
var array integer: list is 0 times 0;
var array integer: reversedList is 0 times 0;
var integer: score is 0;
var integer: index is 0;
var integer: number is 0;
var integer: reverse is 0;
begin
for number range sortedList do
index := rand(1, succ(length(list)));
list := list[.. pred(index)] & [] (number) & list[index ..];
end for;
repeat
write("Current list: ");
for number range list do
write(number <& " ");
end for;
repeat
write(" Digits to reverse? ");
if reverse < 2 or reverse > 9 then
write("Please enter a value between 2 and 9.");
end if;
until reverse >= 2 and reverse <= 9;
incr(score);
reversedList := 0 times 0;
for index range reverse downto 1 do
reversedList &:= list[index];
end for;
list := reversedList & list[succ(reverse) ..];
until list = sortedList;
writeln("Congratulations, you sorted the list in " <& score <& " reversals.");
end func;
```

{{out}}

```txt

Current list: 7 6 2 9 1 3 4 5 8  Digits to reverse? 4
Current list: 9 2 6 7 1 3 4 5 8  Digits to reverse? 9
Current list: 8 5 4 3 1 7 6 2 9  Digits to reverse? 8
Current list: 2 6 7 1 3 4 5 8 9  Digits to reverse? 3
Current list: 7 6 2 1 3 4 5 8 9  Digits to reverse? 7
Current list: 5 4 3 1 2 6 7 8 9  Digits to reverse? 5
Current list: 2 1 3 4 5 6 7 8 9  Digits to reverse? 2
Congratulations, you sorted the list in 7 reversals.

```

## Sidef

{{trans|Perl}}

```ruby
var turn = 0;
var jumble = @(1..9).bshuffle;        # best-shuffle

for (turn; jumble != 1..9; ++turn) {
printf("%2d: %s - Flip how many digits ? ", turn, jumble.join(' '));
var d = read(Number) \\ break;
jumble[0 .. d-1] = [jumble[0 .. d-1]].reverse...;
}

print "    #{jumble.join(' ')}\n";
print "You won in #{turn} turns.\n";
```

## Tcl

```tcl
package require Tcl 8.5
# Simple shuffler, not very efficient but good enough for here
proc shuffle list {
set result {}
while {[llength \$list]} {
set i [expr {int([llength \$list] * rand())}]
lappend result [lindex \$list \$i]
set list [lreplace \$list \$i \$i]
}
return \$result
}
# Returns the list with the prefix of it reversed
proc flipfirst {list n} {
concat [lreverse [lrange \$list 0 \$n-1]] [lrange \$list \$n end]
}

# Core game engine; list to play with is optional argument
proc nrgame {{target "1 2 3 4 5 6 7 8 9"}} {
set nums \$target
while {\$nums eq \$target} {set nums [shuffle \$nums]}
set goes 0
while {\$nums ne \$target} {
incr goes
puts -nonewline "#\${goes}: List is '[join \$nums {, }]', how many to reverse? "
flush stdout
gets stdin n
if {\$n eq "q"} {return quit}
# Input validation would go here
set nums [flipfirst \$nums \$n]
}
return \$goes
}

# Print some instructions and wait for the user to win
puts "Welcome to the Number Reversal Game!"
puts "------------------------------------"
puts "I'll show you a list of numbers, you need to reverse prefixes of them"
puts "to get the whole list in ascending order. A 'q' will quit early.\n"
puts ""
set outcome [nrgame]
if {\$outcome ne "quit"} {
puts "\nYou took \$outcome attempts to put the digits in order."
}
```

Sample output:

```txt

Welcome to the Number Reversal Game!
------------------------------------
I'll show you a list of numbers, you need to reverse prefixes of them
to get the whole list in ascending order. A 'q' will quit early.

#1: List is '8, 6, 2, 5, 7, 9, 3, 1, 4', how many to reverse? 6
#2: List is '9, 7, 5, 2, 6, 8, 3, 1, 4', how many to reverse? 9
#3: List is '4, 1, 3, 8, 6, 2, 5, 7, 9', how many to reverse? 4
#4: List is '8, 3, 1, 4, 6, 2, 5, 7, 9', how many to reverse? 8
#5: List is '7, 5, 2, 6, 4, 1, 3, 8, 9', how many to reverse? 7
#6: List is '3, 1, 4, 6, 2, 5, 7, 8, 9', how many to reverse? 4
#7: List is '6, 4, 1, 3, 2, 5, 7, 8, 9', how many to reverse? 6
#8: List is '5, 2, 3, 1, 4, 6, 7, 8, 9', how many to reverse? 5
#9: List is '4, 1, 3, 2, 5, 6, 7, 8, 9', how many to reverse? 4
#10: List is '2, 3, 1, 4, 5, 6, 7, 8, 9', how many to reverse? 2
#11: List is '3, 2, 1, 4, 5, 6, 7, 8, 9', how many to reverse? 3

You took 11 attempts to put the digits in order.

```

## TUSCRIPT

```tuscript

\$\$ MODE TUSCRIPT
numbers=RANDOM_NUMBERS (1,9,9),nr=0

SECTION check
LOOP o,n=numbers
IF (n!=o) THEN
DO PRINT
EXIT
ELSEIF (n==9&&o==9) THEN
DO PRINT
PRINT " You made it ... in round ",r
STOP
ELSE
CYCLE
ENDIF
ENDLOOP
ENDSECTION

SECTION print
PRINT numbers
ENDSECTION

DO PRINT
LOOP r=1,14
IF (nr>=0&&nr<10) THEN
ASK "Reverse - how many?": nr=""
i=""
LOOP n=1,nr
i=APPEND(i,n)
ENDLOOP
numbers   =SPLIT (numbers)
reverse_nr=SELECT (numbers,#i,keep_nr), reverse_nr=REVERSE(reverse_nr)
numbers   =APPEND (reverse_nr,keep_nr), numbers   =JOIN   (numbers)
DO check
ENDIF
ENDLOOP

```

Output:
2'1'7'8'5'6'4'9'3
Reverse - how many? >8
9'4'6'5'8'7'1'2'3
Reverse - how many? >9
3'2'1'7'8'5'6'4'9
Reverse - how many? >5
8'7'1'2'3'5'6'4'9
Reverse - how many? >8
4'6'5'3'2'1'7'8'9
Reverse - how many? >3
5'6'4'3'2'1'7'8'9
Reverse - how many? >2
6'5'4'3'2'1'7'8'9
Reverse - how many? >6
1'2'3'4'5'6'7'8'9
You made it ... in round 7

```

## UNIX Shell

This task becomes easier if your shell has arrays and a random number generator. POSIX shells have not those. If you would do this task with a POSIX shell, then you would pretend arrays with eval, as in eval "\\$array_\$index=value", and you would implement your own random number generator.

This solution uses the arrays and the random number generator from the Korn shell. It also shows a few other Korn features: the (( )) and [[ ]] commands, the print statement, and some local integer variables in some function.

{{trans|AWK}}
{{works with|pdksh|5.2.14}}

```bash
print "\nWelcome to the number reversal game!\n"

print "You must put the numbers in order from 1 to 9."
print "Your only moves are to reverse groups of numbers"
print "on the left side of the list."

integer list score

# start a new game
function newgame {
integer i j t

# score = number of moves
((score = 0))

# list = array of numbers
set -A list 1 2 3 4 5 6 7 8 9
while true; do
# Knuth shuffle
((i = 9))
while ((i > 1)); do
# get random j from 0 to i - 1
((j = RANDOM))
((j < 32768 % i)) && continue
((j %= i))

# decrement i, swap list[i] with list[j]
((i -= 1))
((t = list[i]))
((list[i] = list[j]))
((list[j] = t))
done
win || break
done
}

# numbers in order?
function win {
integer i

# check if list == 1, list == 2, ...
((i = 0))
while ((i < 9)); do
((list[i] != i + 1)) && return 1
((i += 1))
done
return 0
}

# reverse first \$1 elements of list
function reverse {
integer left right t

((left = 0))
((right = \$1 - 1))
while ((right > left)); do
((t = list[left]))
((list[left] = list[right]))
((list[right] = t))
((left += 1))
((right -= 1))
done
}

integer i

newgame
while true; do
((i = 0))
while ((i < 8)); do
printf "%d, " \${list[i]}
((i += 1))
done
printf "%d\n" \${list}

if win; then
print "YOU WIN!"
printf "Your score is %d moves.\n" \$score
print -n "Would you like to play again (y/n)? "

if read again && [[ \$again = @(y|Y)* ]]; then
newgame
else
print "\n\nBye!"
exit
fi
else
print -n "How many numbers to reverse? "

((score += 1))
reverse \$i
else
print "\n\nBye!"
exit
fi
fi
done
```

## VBA

{{incomplete|VBA|No check for an initial scramble to the sorted state (refer to talk page for relevant discussion on issue).}}
{{trans|Phix}}
```vb
Private Function shuffle(ByVal a As Variant) As Variant
Dim t As Variant, i As Integer
For i = UBound(a) To LBound(a) + 1 Step -1
j = Int((UBound(a) - LBound(a) + 1) * Rnd + LBound(a))
t = a(i)
a(i) = a(j)
a(j) = t
Next i
shuffle = a
End Function
Private Sub reverse(ByRef a As Variant, n As Integer)
Dim b As Variant
b = a
For i = 1 To n
a(i) = b(n + 1 - i)
Next i
End Sub
Public Sub game()
Debug.Print "Given a jumbled list of the numbers 1 to 9"
Debug.Print "you must select how many digits from the left to reverse."
Debug.Print "Your goal is to get the digits in order with 1 on the left and 9 on the right."

inums = [{1,2,3,4,5,6,7,8,9}]
Dim nums As Variant
Dim turns As Integer, flip As Integer

nums = shuffle(inums)

Do While True
Debug.Print turns; ":";
For Each x In nums: Debug.Print x;: Next x
Debug.Print
flag = False
For i = LBound(nums) To UBound(nums)
If nums(i) <> inums(i) Then
flag = True
Exit For
End If
Next i
If flag Then
flip = InputBox(" -- How many numbers should be flipped? ")
reverse nums, flip
turns = turns + 1
Else
Exit Do
End If
Loop

Debug.Print "You took"; turns; "turns to put the digits in order."
End Sub
```
{{out}}

```txt
Given a jumbled list of the numbers 1 to 9
you must select how many digits from the left to reverse.
Your goal is to get the digits in order with 1 on the left and 9 on the right.
0 : 1  4  3  9  8  7  6  2  5
1 : 9  3  4  1  8  7  6  2  5
2 : 5  2  6  7  8  1  4  3  9
3 : 8  7  6  2  5  1  4  3  9
4 : 3  4  1  5  2  6  7  8  9
5 : 5  1  4  3  2  6  7  8  9
6 : 2  3  4  1  5  6  7  8  9
7 : 4  3  2  1  5  6  7  8  9
8 : 1  2  3  4  5  6  7  8  9
You took 8 turns to put the digits in order.
```

## XPL0

```XPL0
int  Taken, I, Digit, Num, Score, Rev, Temp;
char List(9);
include c:\cxpl\codes;
\make jumbled list of digits 1 to 9
[loop   [Taken:= 0;     \bit array indicates which digits are taken
for I:= 0 to 9-1 do
[repeat Digit:= Ran(9)+1 until (Taken & 1< List(I+1) then quit;
];                      \quit loop when digits are not in ascending order
Score:= 0;
loop    [for I:= 0 to 9-1 do [IntOut(0, List(I));  ChOut(0, ^ )];
Num:= 0;  for I:= 0 to 9-1 do Num:= Num*10 + List(I);
if Num = 123456789 then quit;
Text(0, "^M^JReverse how many digits? ");  Rev:= IntIn(0);
for I:= 0 to Rev/2-1 do
[Temp:= List(I);  List(I):= List(Rev-1-I);  List(Rev-1-I):= Temp];
Score:= Score+1;
];
Text(0, "^M^JCongrats! You did it in "); IntOut(0, Score);
Text(0, " moves!!^M^J");
]
```

Example output:

```txt

1 3 5 4 8 9 7 2 6
Reverse how many digits? 3
5 3 1 4 8 9 7 2 6
Reverse how many digits? 4
4 1 3 5 8 9 7 2 6
Reverse how many digits? 5
8 5 3 1 4 9 7 2 6
Reverse how many digits? 2
5 8 3 1 4 9 7 2 6

```

## zkl

{{trans|AutoHotkey}}

```zkl
correctList,scrambledList,N:=[1..9].walk(), correctList.shuffle(),correctList.len();
correctList,scrambledList=correctList.concat(""), scrambledList.concat(""); // list to string
attempts:=0;
while(scrambledList!=correctList){ // Repeat until the sequence is correct
n:=ask(("[%d] %s How many numbers (from the left) should be flipped? ")
.fmt(attempts,scrambledList));
try{ n=n.toInt() }catch{ println("Not a number"); continue; }
if(not (0<=n

```