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https://github.com/omerkel/sokoban

倉庫番 - Sokoban solitaire puzzle game
https://github.com/omerkel/sokoban

entertainment games puzzle puzzle-game single-player single-player-game solitaire solitaire-game

Last synced: 13 days ago
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倉庫番 - Sokoban solitaire puzzle game

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README 

        
Sokoban icon Sokoban

=============================================



倉庫番 - Sokoban solitaire logic puzzle game



The term _Sokoban_ means _warehouse keeper_. The player controls a warehouse keeper.

He has to push boxes onto marked storage locations to solve each level.



The original game of Sokoban was created back in the early 1980s Home Computer era by

Hiroyuki Imabayashi then distributed by Thinking Rabbit, a Japanese software house.



## Android APK available for install



Android APK available https://github.com/OMerkel/Sokoban/releases



## Usage of Browser Javascript Version



Simply start a session of the [Sokoban game](https://omerkel.github.io/Sokoban/html5/src)

in your browser window. 



## Usage of Dart Version



You can find a version written in Dart programming language in this repository, too.

This is a ASCII graphics version played on the command line console (STDIN/STDOUT).

A Dart SDK is needed to run it ( https://dart.dev ).



```

$ dart --version

Dart VM version: 2.4.0 (Unknown timestamp) on "linux_x64"

$ cd dart

$ dart sokoban.dart ../3rdParty/Levels/Microban.txt 3

Found 155 levels in Microban.txt.

Level 3:

  ####

###  ####

#     $ #

# #  #$ #

# . .#@ #

#########

```



What the symbols represent in the level files and on screen while playing the game:



```Dart

var symbol = {

  'floor':            " ",

  'wall':             "#",

  'box':              "\$",

  'sokoban':          "@",

  'storage':          ".",

  'boxOnStorage':     "*",

  'sokobanOnStorage': "+"

};

```



Use the following keys to control the Sokoban



```Dart

var key = {

  'left':  'h',

  'down':  'j',

  'up':    'k',

  'right': 'l'

};

```



__Ctrl+D__ exits the current game



## Solving Sokoban Levels



```

$ python --version

Python 3.5.2

$ cd python

$ python sokoban_solver_1.py 0

###

#.#

# #

#$#

#@#

###

Push box onto storage!

UU

0.000347137451171875 seconds

```



The selected level or challenge indexed by '0' on the command line is shown with following symbols.



```python

levels = {

  'symbol' : {

    'floor':            " ",

    'wall':             "#",

    'box':              "$",

    'sokoban':          "@",

    'storage':          ".",

    'boxOnStorage':     "*",

    'sokobanOnStorage': "+",

  },

...

```



The solution found is shown below this output of the challenge.



```python

  orientation = {

    'down':  { 'move': 'd', 'push': 'D', 'dx':  0, 'dy':  1 },

    'left':  { 'move': 'l', 'push': 'L', 'dx': -1, 'dy':  0 },

    'up':    { 'move': 'u', 'push': 'U', 'dx':  0, 'dy': -1 },

    'right': { 'move': 'r', 'push': 'R', 'dx':  1, 'dy':  0 }

  }

```



The two uppercase 'UU' in the output indicate that two pushes have to be performed to solve the challenge.



__sokoban_solver_1.py__ works for simple levels in very low time.



Solving challenge 3 by UUluRR and 5 using the moves and pushes llDurrdL:



```

$ python sokoban_solver_1.py 3

######

#   .#

#  ###

##$#

 #@#

 ###

Around the corner.

UUluRR

0.003311634063720703 seconds

$ python sokoban_solver_1.py 5

#####

#  @#

#*$ #

#.###

###

Easy going!

llDurrdL

0.016065359115600586 seconds

```



As soon as the warehouse keeper gets more liberties or freedom to move the time to solve the challenges

increases enormously. This is since the _brute-force-attack_ to find the solution traverses situations

over and over again even if the same situation has been _visited_ and thus has been analysed before.

Most likely then the computer runs _out of memory_ or you get a _memory error_ or _couldn't allocate_

more memory after a while.



```

$ python sokoban_solver_1.py 4

  ######

  #.   #

### ##$###

#@ $   . #

#    ####*

######

```



Time to wait or give up...



__sokoban_solver_2.py__ avoids traversing already visited situations while searching for the solution.

This is done by storing each level situation in a set named _visited_ in the python code.



```

$ python sokoban_solver_2.py 4

  ######

  #.   #

### ##$###

#@ $   . #

#    ####*

######



drrruLuurrrDullldddlluRdrUUdrrR

0.09712076187133789 seconds

$ python sokoban_solver_2.py 6

#######

#.@ # #

#$* $ #

#   $ #

# ..  #

#  *  #

#######

Not so easy...

DDrdrruLruLLDllU

3.3833835124969482 seconds

$ python sokoban_solver_2.py 7

 #####

##   #

#@$  #

#. $##

#.  #

#####

On the other side

RurrdLulDlddrrULuurrdLulDDrdL

0.0918741226196289 seconds

```



Still the Sokoban solver has limitations to find solutions for levels like the following one.



```

$ python sokoban_solver_2.py 8

    #####

    #   #

    #$  #

  ###  $###

  #  $  $ #

### # # # #*#####

#   # ### ##  ..#

# $  $      @ ..#

##### #### #  ..#

    #      *#####

    ########

Moderate challenge

```



Again memory consumption is high. And it continues to search for solutions even if it is

clear that a specific solution is already unsolveable. E.g. if a box gets pushed into

a corner and can not be pushed out of the corner anymore. Like this:



```

    #####

    #$  #

    #   #

...

```



A box gets immovable as soon as it gets pushed into a corner of walls or even other boxes.

Such corners look like this



```



   #$

@$  $



```



If the Sokoban pushes the box twice right (RR) into the corner shape then none of the boxes

are moveable any longer.



```

##########

#        #

# @  *$  #

#.   #$  #

#.       #

##########

```



As another example the warehouse keeper can not move any box in this situation.

The situation is unsovable. Meaning the strategy to optimize the search finding a

solution is to avoid pushes of a box into such corner shapes as long as the compacted

shape is not part of the intended solution.



Furthermore to reduce memory consumption of the remaining search tree instead of

storing the whole level scenario it is sufficient to store a much shorter unique

identifier of the level scenario. This is usually done by storing so called hash

values representing the data. Mind that you have to avoid hash value collisions.

Python is helping here at this point since some data representations are already

stored using hash values. So it is not needed to implement a hash function. Instead

the python internal hash function of the data is used. Since lists do not own a hash

value but strings the list is joined as a string:



```Python

    visited = set([hash(''.join(self.getLevel()))])

    ...

          sHash = hash(''.join(s.getLevel()))

          if sHash not in visited:

            ...

            visited.add(sHash)    

```



Although __sokoban_solver_3.py__ will allow to render a solution for a greater

set of levels the runtime is still considered being high on nowadays machines.



```

$ python sokoban_solver_3.py 8

    #####

    #   #

    #$  #

  ###  $###

  #  $  $ #

### # # # #*#####

#   # ### ##  ..#

# $  $      @ ..#

##### #### #  ..#

    #      *#####

    ########

Moderate challenge

llluuuLLUllDlldddrRRRRRRRRdrUllllllllllulldRRRRRRRRRRRuRRlDlllluuullulldDDuulldd

drRRRRRRRRdRRlUlllluuullLulDDDuulldddrRRRRRRRRuRDlllluuullluuurDDluulDDDDDuulldd

drRRRRRRRRRRllllluuulLLulDDDuulldddrRRRRRRRRRldR

5176.865227937698 seconds

$ python sokoban_solver_3.py 9

*####        ####*

##  ##########  ##

#                #

#  *###########  #

## #*  #  #   # ##

 # #      #   # #

 # #  ##$ #  ## #

 # ## #  $#$ #  #

 # *# #      ## #

 # ## #  ##   # ##

##*#  #########  #

# .#             #

#@..#  #######  ##

*#######     ####*

A long way...

urUUUUUUUUluRRRRRRRRRRRRRurDDDDDDDDDrdLLLLLLLLLLdlUUUUUUluRRRRDrDuluurDDlDlddrUU

UruLdddRRRdrUUUlDuuurrdLulDDrddLLLUluuLLulDDDDDDldRRRRRRRRRRdrUUUUUUUUUruLLLLLLL

LLLLLLulDDDDDDDDDDldRuuuuuuuuuurrrrrrrrrrrrrdddddddddlllllllllluuuuuurrrrDDllddr

UUdRRRdrUUUlDuuurrdLdddLLLulUruLLLulDDDDDDldRRRRRRRRRRdrUUUUUUUUUruLLLLLLLLLLLLL

ulDDDDDDDDDDuuuuuuuuurrrrrrrrrrrrrdddddddddlllllllllluuuuuurrrddlddrUUUruLLLulDD

DDDDldRRRRRRRRRRdrUUUUUUUUUruLLLLLLLLLLLLLulDDDDDDDDDuuuuuuuurrrrrrrrrrrrrdddddd

dddlllllllllluuuuuurrrdddrrruuruulDDDrdLLLullddrUUUruLLLulDDDDDDldRRRRRRRRRRdrUU

UUUUUUUruLLLLLLLLLLLLLulDDDDDDDD

14102.903747797012 seconds

```



There is still enough room for improvements...



## Links and Third Party



* https://en.wikipedia.org/wiki/Sokoban



Due to its popularity there are free level collections available in the community.

A huge and widely spread level collection has been created by David W. Skinner

named Microban and Sasquatch.



* http://www.abelmartin.com/rj/sokobanJS/Skinner/David%20W.%20Skinner%20-%20Sokoban.htm



Various level formats have been defined that are used in the community.

These simplify to use the same level files in different Sokoban implementations.



* http://www.sokobano.de/wiki/index.php?title=Level_format



More Sokoban resources, links and information...



* http://www.sokobano.de



Dart programming language



* https://dart.dev

* https://dart.dev/tools/sdk



## Contributors / Authors



Oliver Merkel



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