sudoku solver application

A script for creating a sudoku solver application, simply insert top portion into the head tags of your webapage and the bottom code into the body. You can see a live example of this code in use at sudoku solver while not very advanced graphically the sudoku solver is completely functional enjoy!

Insert Into head of Page

<script type="text/javascript"> // Sudoku Solver in JavaScript. // Copyright (C) 2005 John D. Ramsdell // // This program is free software; you can redistribute it and/or // modify it under the terms of the GNU General Public License // as published by the Free Software Foundation; either version 2 // of the License, or (at your option) any later version. // // This program is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details at // http://www.gnu.org/copyleft/gpl.html.

// Each cell has a value and set. When the cell has been determined, // value will be non-zero, otherwise it is zero. The set has a bit // set for each value of the cell that has yet to be eliminated as a // possible value for this cell. When a cell contains the empty set, // the board is inconsistent.

// The basic dimension of the board var dim = 3; var dim2 = dim * dim; // The set of all possibilities var all = (1 << dim2) - 1;

// The cell constructor takes strings or numbers as arguments. function Cell(val) { var cell = new Object; val = Number(val); if (0 < val && val <= 9) { cell.val = val; cell.set = 1 << (val - 1); } else { cell.val = 0; cell.set = all; } return cell; }

// A board is a 3*3*3*3 array of cells. In a board[i][j][k][l] // reference, i is the major row, j is in minor row, k is the major

http://sudokusolver.info/

// column, and l is the minor column.

function mkarray(n) { var i; if (n <= 0) return null; n--; var a = new Array(dim); for (i = 0; i < dim; i++) a[i] = mkarray(n); return a; }

// Construct a board from the form. function Board() { var i, j, k, l; var board = mkarray(4); var e = 0; with (top.document.forms[0]) for (i = 0; i < dim; i++) for (k = 0; k < dim; k++) for (j = 0; j < dim; j++) for (l = 0; l < dim; l++) board[i][j][k][l] = Cell(elements[e++].value); return board; }

function duplicate(target, source) { var i, j, k, l; for (i = 0; i < dim; i++) for (j = 0; j < dim; j++) for (k = 0; k < dim; k++) for (l = 0; l < dim; l++) { target[i][j][k][l].val = source[i][j][k][l].val; target[i][j][k][l].set = source[i][j][k][l].set; } }

function unknowns() { var i, j, k, l, m; var n = 0; for (i = 0; i < dim; i++) for (j = 0; j < dim; j++) for (k = 0; k < dim; k++) for (l = 0; l < dim; l++) n += card(board[i][j][k][l].set); return n; }

// The number of elements in the set. function card(set) { var m; var n = 0;

for (m = 0; m < dim2; m++) if ((1 << m) & set) n++; return n; }

// The current grid var board;

// The previous grid var previous;

function show_cell(i, j, k, l) { var cell = board[i][j][k][l]; var set = cell.set & all; if (set == 0) return '?'; if (cell.val > 0) return String(cell.val); if (set == all) return '.'; // List possible values in cell. var i, m; var n = 0; var str = ''; for (m = 0; m < dim2; m++) if ((1 << m) & set) { i = m + 1; str += String(i); n++; } if (n == 1) { // The value of the cell has been determined. str += "!"; cell.val = i; } return str; }

// Show current board position using HTML tables. function show() { var bad = false; var tbody = document.createElement("tbody"); for (i = 0; i < dim; i++) { var tri = document.createElement("tr"); for (k = 0; k < dim; k++) { var ibody = document.createElement("tbody"); for (j = 0; j < dim; j++) { var trj = document.createElement("tr"); for (l = 0; l < dim; l++) { var text = show_cell(i, j, k, l); if (text == '?') bad = true;

var node = document.createTextNode(text); var tdl = document.createElement("td"); if (board[i][j][k][l].set != previous[i][j][k][l].set) tdl.setAttribute("class", "changed"); tdl.setAttribute("align", "center"); tdl.appendChild(node); trj.appendChild(tdl); } ibody.appendChild(trj); } var itbl = document.createElement("table"); itbl.setAttribute("border", 1); itbl.setAttribute("width", "100%"); itbl.appendChild(ibody); var tdk = document.createElement("td"); tdk.setAttribute("align", "center"); tdk.appendChild(itbl); tri.appendChild(tdk); } tbody.appendChild(tri); } var tbl = document.createElement("table"); tbl.setAttribute("border", 1); tbl.setAttribute("align", "center"); tbl.appendChild(tbody); document.body.appendChild(tbl); window.scrollBy(0, 1000); duplicate(previous, board); return bad; }

// Show some text. function put(text) { var node = document.createTextNode(text); var par = document.createElement("p"); par.appendChild(node); document.body.appendChild(par); window.scrollBy(0, 100); }

// The following functions implement the various solver strategies. // Each strategy is described by text printed with its use in the // solve function. You can add your own strategies, or delete the // ones here, and discover your own complete set of them.

function uniq(i, j, k, l) { var ii, jj, kk, ll; var set = ~board[i][j][k][l].set;

/* handle row at i, j */

for (kk = 0; kk < dim; kk++) for (ll = 0; ll < dim; ll++)

if (k != kk || l != ll) board[i][j][kk][ll].set &= set;

/* handle column at k, l */

for (ii = 0; ii < dim; ii++) for (jj = 0; jj < dim; jj++) if (i != ii || j != jj) board[ii][jj][k][l].set &= set;

/* handle square at i, k */

for (jj = 0; jj < dim; jj++) for (ll = 0; ll < dim; ll++) if (j != jj || l != ll) board[i][jj][k][ll].set &= set; }

function uniqall() { var i, j, k, l; for (i = 0; i < dim; i++) for (j = 0; j < dim; j++) for (k = 0; k < dim; k++) for (l = 0; l < dim; l++) if (board[i][j][k][l].val > 0) uniq(i, j, k, l); }

function uniqsqr() { var i, j, k, l, m; for (i = 0; i < dim; i++) for (k = 0; k < dim; k++) for (m = 0; m < dim2; m++) { var p = 1 << m; var n = 0; var jj, ll; for (j = 0; j < dim; j++) for (l = 0; l < dim; l++) if (p & board[i][j][k][l].set) { n++; jj = j; ll = l; } if (n == 1) board[i][jj][k][ll].set = p; } }

function uniqrow() { var i, j, k, l, m; for (i = 0; i < dim; i++) for (j = 0; j < dim; j++) for (m = 0; m < dim2; m++) {

if (n == 1) { var kk; for (kk = 0; kk < dim; kk++) if (k != kk) for (l = 0; l < dim; l++) board[i][jj][kk][l].set &= ~p; } } }

function uniqcolline() { var i, j, k, l, m; for (i = 0; i < dim; i++) for (k = 0; k < dim; k++) for (m = 0; m < dim2; m++) { var p = 1 << m; var n = 0; var ll; for (l = 0; l < dim; l++) { var q = 0; for (j = 0; j < dim; j++) if (p & board[i][j][k][l].set) { ll = l; q++; } if (q) n++; } if (n == 1) { var ii; for (ii = 0; ii < dim; ii++) if (i != ii) for (j = 0; j < dim; j++) board[ii][j][k][ll].set &= ~p; } } }

function uniqrowsqr() { var i, j, k, l, m; for (i = 0; i < dim; i++) for (j = 0; j < dim; j++) for (k = 0; k < dim; k++) for (m = 0; m < dim2; m++) { var p = 1 << m; var n = 0; var jj, kk; for (kk = 0; kk < dim; kk++) if (kk != k) for (l = 0; l < dim; l++) if (p & board[i][j][kk][l].set) n++; if (n == 0)

// here when m not in that part of the row for (jj = 0; jj < dim; jj++) if (jj != j) for (l = 0; l < dim; l++) board[i][jj][k][l].set &= ~p; } }

function uniqcolsqr() { var i, j, k, l, m; for (i = 0; i < dim; i++) for (k = 0; k < dim; k++) for (l = 0; l < dim; l++) for (m = 0; m < dim2; m++) { var p = 1 << m; var n = 0; var ii, ll; for (ii = 0; ii < dim; ii++) if (ii != i) for (j = 0; j < dim; j++) if (p & board[ii][j][k][l].set) n++; if (n == 0) // here when m not in that part of the col for (ll = 0; ll < dim; ll++) if (ll != l) for (j = 0; j < dim; j++) board[i][j][k][ll].set &= ~p; } }

function pairsqr() { var i, j, l, k, m, mm; for (i = 0; i < dim; i++) for (k = 0; k < dim; k++) for (m = 0; m < dim2 - 1; m++) for (mm = m + 1; mm < dim2; mm++) { var p = (1 << m) | (1 << mm); var n = 0; for (j = 0; j < dim; j++) for (l = 0; l < dim; l++) if (p & board[i][j][k][l].set) n++; if (n == 2) { for (j = 0; j < dim; j++) for (l = 0; l < dim; l++) { var cell = board[i][j][k][l]; if (p & cell.set) cell.set &= p; } } } }

n++; if (n == 3) { for (i = 0; i < dim; i++) for (j = 0; j < dim; j++) { var cell = board[i][j][k][l]; if (p & cell.set) cell.set &= p; } } } }

function quadsqr() { var i, j, l, k, m, mm, mmm, mmmm; for (i = 0; i < dim; i++) for (k = 0; k < dim; k++) for (m = 0; m < dim2 - 3; m++) for (mm = m + 1; mm < dim2 - 2; mm++) for (mmm = mm + 1; mmm < dim2 - 1; mmm++) for (mmmm = mmm + 1; mmmm < dim2; mmmm++) { var p = (1 << m) | (1 << mm) | (1 << mmm) | (1 << mmmm); var n = 0; for (j = 0; j < dim; j++) for (l = 0; l < dim; l++) if (p & board[i][j][k][l].set) n++; if (n == 4) { for (j = 0; j < dim; j++) for (l = 0; l < dim; l++) { var cell = board[i][j][k][l]; if (p & cell.set) cell.set &= p; } } } }

function quadrow() { var i, j, k, l, m, mm, mmm; for (i = 0; i < dim; i++) for (j = 0; j < dim; j++) for (m = 0; m < dim2 - 3; m++) for (mm = m + 1; mm < dim2 - 2; mm++) for (mmm = mm + 1; mmm < dim2 - 1; mmm++) for (mmmm = mmm + 1; mmmm < dim2; mmmm++) { var p = (1 << m) | (1 << mm) | (1 << mmm) | (1 << mmmm); var n = 0; for (k = 0; k < dim; k++) for (l = 0; l < dim; l++) if (p & board[i][j][k][l].set) n++; if (n == 4) { for (k = 0; k < dim; k++)

for (l = 0; l < dim; l++) { var cell = board[i][j][k][l]; if (p & cell.set) cell.set &= p; } } } }

function quadcol() { var i, j, k, l, m, mm, mmm; for (k = 0; k < dim; k++) for (l = 0; l < dim; l++) for (m = 0; m < dim2 - 3; m++) for (mm = m + 1; mm < dim2 - 2; mm++) for (mmm = mm + 1; mmm < dim2 - 1; mmm++) for (mmmm = mmm + 1; mmmm < dim2; mmmm++) { var p = (1 << m) | (1 << mm) | (1 << mmm) | (1 << mmmm); var n = 0; for (i = 0; i < dim; i++) for (j = 0; j < dim; j++) if (p & board[i][j][k][l].set) n++; if (n == 4) { for (i = 0; i < dim; i++) for (j = 0; j < dim; j++) { var cell = board[i][j][k][l]; if (p & cell.set) cell.set &= p; } } } }

// This is the main routine. It creates a board, and then attempts to // solve the puzzle it contains. function solve() { board = Board(); previous = Board(); var u = unknowns(); for (;;) { var v = u; if (show()) { put("The board is inconsistent."); board = null; return true; } if (u == dim2 * dim2) break; uniqall(); u = unknowns(); if (u < v) { put("By known value must be unique in row, column, and square.");

continue; } uniqsqr(); u = unknowns(); if (u < v) { put("By only one place for value in square."); continue; } uniqrow(); u = unknowns(); if (u < v) { put("By only one place for value in row."); continue; } uniqcol(); u = unknowns(); if (u < v) { put("By only one place for value in column."); continue; } uniqrowline(); u = unknowns(); if (u < v) { put("By values in square preclude others in a row."); continue; } uniqcolline(); u = unknowns(); if (u < v) { put("By values in square preclude others in a column."); continue; } uniqcolsqr(); u = unknowns(); if (u < v) { put("By only one columm value in square."); continue; } uniqrowsqr(); u = unknowns(); if (u < v) { put("By only one row for value in square."); continue; } pairsqr(); u = unknowns(); if (u < v) { put("By pair has only two places in square."); continue; } pairrow(); u = unknowns(); if (u < v) {

put("By pair has only two places in row."); continue; } paircol(); u = unknowns(); if (u < v) { put("By pair has only two places in column."); continue; } triplesqr(); u = unknowns(); if (u < v) { put("By triple has only three places in square."); continue; } triplerow(); u = unknowns(); if (u < v) { put("By triple has only three places in row."); continue; } triplecol(); u = unknowns(); if (u < v) { put("By triple has only three places in column."); continue; } quadsqr(); u = unknowns(); if (u < v) { put("By quad has only four places in square."); continue; } quadrow(); u = unknowns(); if (u < v) { put("By quad has only four places in row."); continue; } quadcol(); u = unknowns(); if (u < v) { put("By quad has only four places in column."); continue; } break; } put("Final board."); if (show()) { put("The board is inconsistent."); board = null; return true; }

if (u > dim2 * dim2) put("The board is unfinished."); board = null; return true; }

// Ensures a form value is blank or a non-zero digit. function verify(e) { with (top.document.forms[0].elements[e]) { if (value != '1' && value != '2' && value != '3' && value != '4' && value != '5' && value != '6' && value != '7' && value != '8' && value != '9') value = ''; } return true; }

// Load a puzzle from the text area.

function load() { var p = top.document.forms[0].puzzle.value; // Ignore white space, hyphen, vertical bar, plus sign, and comments. p = p.replace(/[\s-|+]|\(.*\)/g, ''); if (parse(p)) { alert('Bad puzzle syntax.'); return true; } var i, j, k, l; var e = 0; with (top.document.forms[0]) for (i = 0; i < dim; i++) for (k = 0; k < dim; k++) for (j = 0; j < dim; j++) for (l = 0; l < dim; l++) { var val = p.charAt(l + dim * (k + dim * (j + dim * i))); if (val == '.') val = ''; elements[e++].value = val; } return true; }

function parse(puzzle) { var n = puzzle.length; var i; for (i = 0; i < n; i++) { var value = puzzle.charAt(i);

if (value != '.' && value != '1' && value != '2' && value != '3' && value != '4' && value != '5' && value != '6' && value != '7' && value != '8' && value != '9') return true; } return false; }</script>

Insert Into Body

<td> <div class="center"><form action="dummy" onsubmit="return false;"> <table BORDER > <caption><tbody> <br></tbody></caption>

<tr> <td> <table BORDER > <caption><tbody> <br></tbody></caption>

<tr> <td ALIGN=CENTER><input name="digit" size="1" value="" onchange="return verify(0);" type="text"></td>

<td ALIGN=CENTER><input name="digit" size="1" value="" onchange="return verify(1);" type="text"></td>

<td ALIGN=CENTER><input name="digit" size="1" value="" onchange="return verify(2);" type="text"></td> </tr>




<tr> <td ALIGN=CENTER><input name="digit" size="1" value="" onchange="return verify(6);"

type="text"></td>


<td ALIGN=CENTER><input name="digit" size="1" value="" onchange="return verify(8);" type="text"></td> </tr> </table> </td>

<td> <table BORDER > <caption><tbody> <br></tbody></caption>










<td>














<td ALIGN=CENTER><input name="digit" size="1" value="" onchange="return verify(41);"

type="text"></td> </tr>














</tr> </table> </td> </tr>












<tr>














<tr> <td ALIGN=CENTER><input name="digit" size="1" value="" onchange="return verify(75);"

type="text"></td>






The scipt was written by J Ramsdell see credits on top and provided courtesy of http://sudokusolver.info

sudoku solver application

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