p01/LICENSE.txt

## README.md

      
    Raw
  

              README.md
            
          
    Sudoku Solver in 140 bytes

Solve a Sudoku grid only using magic, recursion, and 140bytes of brute force.

  
## annotated.js
function R
(
    a,  // the array representing the sudoko grid

        // placeholder arguments
    i,  // index of the last empty cell
    j,  // index to check the candidates for the cell 'i'
    m,  // candidate number for the the cell 'i'
    g   // flag whether 'm' is a already used in the same row|col|node as 'i'
){
    // phase 1: look for an empty cell
    for
    (
       i=80;
       a[i];        // keep going if the cell isn't empty
       i--||+a      // decrease the index and call 'a.toString()' if we went through the whole grid
    );
    // phase 2: check all candidate numbers for the cell 'i'
    for
    (
      m=10;
      g=a[i]=--m;   // put the candidate in the cell 'i' already and set 'g' to something truthy
                    // at the end of phase 2, the cell 'i' is reset to 0 for "higher" branches of the recursion
        g&&R(a)     // recurse if 'm' isn't already used in the same row|col|node as 'i'
   )
      // phase 3: check if the candidate number is used already
      for(j in a)           // loop through the whole grid again
           g*=              // turn 'g' falsy if
              a[j^i==j]     // we are not on the cell 'i'
              ^m            // and the cell 'j' is set to 'm'
              ||            // and we are in the same row|col|node as 'i'
              i/9^j/9&&i%9^j%9&&i/27^j/27|i%9/3^j%9/3
}

## index.js
function R(a,i,j,m,g){for(i=80;a[i];i--||+a);for(m=10;g=a[i]=--m;g&&R(a))for(j in a)g*=a[j^i==j]^m||i/9^j/9&&i%9^j%9&&i/27^j/27|i%9/3^j%9/3}

## LICENSE.txt
            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
                    Version 2, December 2004

 Copyright (C) 2011 Mathieu 'p01' Henri <http://www.p01.org/releases/>

 Everyone is permitted to copy and distribute verbatim or modified
 copies of this license document, and changing it is allowed as long
 as the name is changed.

            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION

  0. You just DO WHAT THE FUCK YOU WANT TO.

## package.json
{
  "name": "sudokuSolver",

  "description": "Brute force sudoku solver.",

  "keywords": [
    "sudoku",
    "solver",
    "recursive",
    "brute force"
  ]
}

## test.html
<!doctype html>
<title>Sudoku Solver in 140bytes</title>

<div>Expected value: <b>4,2,8,1,5,9,6,7,3,1,9,6,3,7,4,8,2,5,3,7,5,8,6,2,9,4,1,9,8,1,4,2,3,5,6,7,5,6,4,7,1,8,3,9,2,7,3,2,5,9,6,1,8,4,2,4,3,6,8,1,7,5,9,6,1,7,9,4,5,2,3,8,8,5,9,2,3,7,4,1,6</b></div>
<div>Actual value: <b id="ret"></b></div>

<script>

var testGrid = [0,0,0,1,5,0,0,7,0,1,0,6,0,0,0,8,2,0,3,0,0,8,6,0,0,4,0,9,0,0,4,0,0,5,6,7,0,0,4,7,0,8,3,0,0,7,3,2,0,0,6,0,0,4,0,4,0,0,8,1,0,0,9,0,1,7,0,0,0,2,0,8,0,5,0,0,3,7,0,0,0];

var myFunction = function R(a,i,j,m,g){for(i=80;a[i];i--||+a);for(m=10;g=a[i]=--m;g&&R(a))for(j in a)g*=a[j^i==j]^m||i/9^j/9&&i%9^j%9&&i/27^j/27|i%9/3^j%9/3};

(function(f)
{
  var original=Array.prototype.toString;
  Array.prototype.toString=function sudokuToString()
  {
    if( (sudokuToString.caller||arguments.caller)==f )
      document.getElementById( "ret" ).textContent= original.call(this);

    return original.call(this);
  }
})( myFunction );

myFunction( testGrid );

</script>
	function R
	(
	a, // the array representing the sudoko grid

	// placeholder arguments
	i, // index of the last empty cell
	j, // index to check the candidates for the cell 'i'
	m, // candidate number for the the cell 'i'
	g // flag whether 'm' is a already used in the same row\|col\|node as 'i'
	){
	// phase 1: look for an empty cell
	for
	(
	i=80;
	a[i]; // keep going if the cell isn't empty
	i--\|\|+a // decrease the index and call 'a.toString()' if we went through the whole grid
	);
	// phase 2: check all candidate numbers for the cell 'i'
	for
	(
	m=10;
	g=a[i]=--m; // put the candidate in the cell 'i' already and set 'g' to something truthy
	// at the end of phase 2, the cell 'i' is reset to 0 for "higher" branches of the recursion
	g&&R(a) // recurse if 'm' isn't already used in the same row\|col\|node as 'i'
	)
	// phase 3: check if the candidate number is used already
	for(j in a) // loop through the whole grid again
	g*= // turn 'g' falsy if
	a[j^i==j] // we are not on the cell 'i'
	^m // and the cell 'j' is set to 'm'
	\|\| // and we are in the same row\|col\|node as 'i'
	i/9^j/9&&i%9^j%9&&i/27^j/27\|i%9/3^j%9/3
	}
	DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
	Version 2, December 2004

	Copyright (C) 2011 Mathieu 'p01' Henri <http://www.p01.org/releases/>

	Everyone is permitted to copy and distribute verbatim or modified
	copies of this license document, and changing it is allowed as long
	as the name is changed.

	DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
	TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION

	0. You just DO WHAT THE FUCK YOU WANT TO.
	{
	"name": "sudokuSolver",

	"description": "Brute force sudoku solver.",

	"keywords": [
	"sudoku",
	"solver",
	"recursive",
	"brute force"
	]
	}
	<!doctype html>
	<title>Sudoku Solver in 140bytes</title>

	<div>Expected value: <b>4,2,8,1,5,9,6,7,3,1,9,6,3,7,4,8,2,5,3,7,5,8,6,2,9,4,1,9,8,1,4,2,3,5,6,7,5,6,4,7,1,8,3,9,2,7,3,2,5,9,6,1,8,4,2,4,3,6,8,1,7,5,9,6,1,7,9,4,5,2,3,8,8,5,9,2,3,7,4,1,6</b></div>
	<div>Actual value: <b id="ret"></b></div>

	<script>

	var testGrid = [0,0,0,1,5,0,0,7,0,1,0,6,0,0,0,8,2,0,3,0,0,8,6,0,0,4,0,9,0,0,4,0,0,5,6,7,0,0,4,7,0,8,3,0,0,7,3,2,0,0,6,0,0,4,0,4,0,0,8,1,0,0,9,0,1,7,0,0,0,2,0,8,0,5,0,0,3,7,0,0,0];

	var myFunction = function R(a,i,j,m,g){for(i=80;a[i];i--\|\|+a);for(m=10;g=a[i]=--m;g&&R(a))for(j in a)g*=a[j^i==j]^m\|\|i/9^j/9&&i%9^j%9&&i/27^j/27\|i%9/3^j%9/3};

	(function(f)
	{
	var original=Array.prototype.toString;
	Array.prototype.toString=function sudokuToString()
	{
	if( (sudokuToString.caller\|\|arguments.caller)==f )
	document.getElementById( "ret" ).textContent= original.call(this);

	return original.call(this);
	}
	})( myFunction );

	myFunction( testGrid );

	</script>