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<?php
declare(strict_types=1);
namespace CoenMooij\Sudoku\Serializer;
use CoenMooij\Sudoku\Puzzle\Grid;
use CoenMooij\Sudoku\Puzzle\Location;
use LengthException;
class GridSerializer
{
public static function serialize(Grid $grid): string
$string = '';
for ($i = 0; $i < Grid::NUMBER_OF_LOCATIONS; $i++) {
$string .= (string) $grid->get(self::getLocationByIndex($i));
}
return $string;
public static function deserialize(string $string): Grid
if (strlen($string) !== Grid::NUMBER_OF_LOCATIONS) {
throw new LengthException();
$grid = new Grid();
$location = self::getLocationByIndex($i);
$value = (int) $string[$i];
if (Grid::valueIsValid($value)) {
$grid->set($location, $value);
return $grid;
public static function getLocationByIndex(int $index): Location
$row = (int) floor($index / Grid::NUMBER_OF_COLUMNS);
$column = $index % Grid::NUMBER_OF_ROWS;
return new Location($row, $column);
coenmooij /
sudoku
