shubhamjain / php-sudoku-solver

A sudoku solver implemented in PHP.

PHP Sudoku Solver

A sudoku solver implemented in PHP. It uses a bruteforce back-tracking algorithim.

Changelog

07/07/2012

• Replaced loop-by check with possibles check which give high performance. Time take to solve 1000 Sudokus: 4.9 seconds. Thanks to deathshawdow.

How to Use

The package consists of two main classes, a solver, SudokuSolver, and a generator, SudokuGenerator.

Using Solver

To use this, you can initialize the SudokuSolver with a long string of numbers where 0 means an empty value. Calling solve() on object will try to solve the Sudoku by Backtracking algorithim. If it cannot be solved, SudokuSolver::NOT_SOLVABLE is returned.

include "SudokuSolver.php";
$sudoku = new SudokuSolver("103000509002109400000704000300502006060000050700803004000401000009205800804000107");
$sudoku->Solve();

print $sudoku->OutputString();

Using Generator

The generator works by filling the sudoku with random values till it is uniquely solvable. Three constants METRIC_EASY, METRIC_MEDIUM, METRIC_HARD can be used to construct sudoku which do nothing fancy except changing the number of filled values.

include "SudokuGenerator.php";
$sudoku = new SudokuGenerator();
$sudoku->GenerateSudoku( SudokuGenerator::METRIC_EASY );

print $sudoku->OutputString();