https://github.com/yugr/sudoku

A simple Sudoku solver that I've done to experiment with SAT/SMT solvers.
https://github.com/yugr/sudoku

haskell minisat sudoku

Last synced: about 5 hours ago
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A simple Sudoku solver that I've done to experiment with SAT/SMT solvers.

• Host: GitHub
• URL: https://github.com/yugr/sudoku
• Owner: yugr
• License: mit
• Created: 2015-12-05T16:04:56.000Z (almost 9 years ago)
• Default Branch: master
• Last Pushed: 2016-02-13T21:02:36.000Z (over 8 years ago)
• Last Synced: 2023-03-08T22:25:49.470Z (over 1 year ago)
• Topics: haskell, minisat, sudoku
• Language: Haskell
• Size: 31.3 KB
• Stars: 3
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE.txt

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README

        
# Overview

A simple Sudoku solver that I've done to experiment with SAT/SMT solvers.

It currently only runs for boards up to 36x36 (k = 6).

For anything bigger, MiniSAT chokes anyway.

# Build

THIS WAS ONLY TESTED ON CYGWIN!!!

Install Haskell Platform and do

```

  $ make clean all -j4

  $ make check

```

To profile, export PROFILE=1 and rebuild.

# Investigation TODO

* plot timing graphs (time vs. #constraints, #constraints vs. #vars)

* see how rule order influences MiniSAT timing:

  * randomize

  * spatial (rules for ij go together)

* find all solutions (plot graph number-of-sols vs. percentage)

* experiment with different encodings:

  * Sudoku as a SAT Problem (http://anytime.cs.umass.edu/aimath06/proceedings/P34.pdf)

  * A SAT-based Sudoku Solver (https://www.lri.fr/~conchon/mpri/weber.pdf)

  * Optimized CNF Encoding for Sudoku Puzzles (http://www.cs.cmu.edu/~hjain/papers/sudoku-as-SAT.pdf)

* see how Haskell people do interfaces to MiniSAT or other external solvers (and how they cope with big CNFs)

* experiment with SMT solvers

* find all solutions

# Code TODO

* pass several lists to CNF instead of one (this should speed things up because we won't copy data when concatting rules)

* store temp files to separate folder

* Haskell coding style

* write Haddocks

* run for inputs up to 100x100 (k=10); ideas:

  * understand where is all the memory going to

  * generate all rules for each cell in one function

  * use streams