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();