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<?php |
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namespace Sudoxu; |
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/** |
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* @package Sudoxu |
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* @author Burak <[email protected]> |
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*/ |
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class Sudoku |
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{ |
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public $sudoku, |
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$result, |
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$number; |
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private $limit, |
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$sq, |
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$chars, |
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$stack = [ |
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'1','2','3','4','5','6','7','8','9', |
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'0','A','B','C','D','E','F','G','H', |
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'I','J','K','L','M','N','O','P','Q', |
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'R','S','T','U','V','W','X','Y','Z' |
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]; |
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/** |
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* Sudoku constructor |
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* |
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* @param int $limit |
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*/ |
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public function __construct($limit = 9) |
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{ |
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ini_set('memory_limit', -1); |
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set_time_limit(0); |
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$this->number = 0; |
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$this->limit = $limit; |
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$this->sq = (int)sqrt($this->limit); |
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return $this; |
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} |
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/** |
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* Limit setter function |
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* |
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* @param int $number |
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* @return $this |
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*/ |
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public function set($number) |
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{ |
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$this->limit = $number; |
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$this->sq = (int)sqrt($this->limit); |
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return $this; |
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} |
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/** |
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* Position of the cell in X-axis |
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* |
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* @param int $cell |
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* @return int |
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*/ |
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private function return_row($cell) |
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{ |
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return (int) floor($cell / $this->limit); |
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} |
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/** |
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* Position of the cell in Y-axis |
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* |
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* @param int $cell |
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* @return int |
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*/ |
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private function return_col($cell) |
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{ |
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return (int) $cell % $this->limit; |
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} |
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/** |
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* Position of the block |
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* |
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* @param int $cell |
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* @return int |
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*/ |
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private function return_block($cell) |
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{ |
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return (int) floor($this->return_row($cell) / $this->sq) * $this->sq + floor($this->return_col($cell) / $this->sq); |
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} |
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/** |
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* Determine if this item unique in the row |
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* |
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* @param string $item |
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* @param int $row |
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* @return bool |
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*/ |
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private function is_possible_row($item, $row) |
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{ |
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$possible = true; |
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for ($x = 0; $x < $this->limit; $x++) |
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{ |
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if (isset($this->sudoku[$row * $this->limit + $x]) && $this->sudoku[$row * $this->limit + $x] == $item) |
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{ |
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$possible = false; |
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} |
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} |
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return $possible; |
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} |
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/** |
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* Determine if this item unique in the column |
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* |
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* @param string $item |
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* @param int $col |
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* @return bool |
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*/ |
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private function is_possible_col($item, $col) |
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{ |
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$possible = true; |
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for ($x = 0; $x < $this->limit; $x++) |
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{ |
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if (isset($this->sudoku[$col + $this->limit * $x]) && $this->sudoku[$col + $this->limit * $x] == $item) |
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{ |
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$possible = false; |
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} |
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} |
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return $possible; |
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} |
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/** |
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* Determine if this item unique in the square block |
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* |
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* @param string $item |
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* @param int $block |
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* @return bool |
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*/ |
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private function is_possible_block($item, $block) |
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{ |
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$possible = true; |
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for ($x = 0; $x < $this->limit; $x++) |
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{ |
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$index = floor($block / $this->sq) * $this->sq * $this->limit + $x % $this->sq + $this->limit * floor($x / $this->sq) + $this->sq * ($block % $this->sq); |
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if (isset($this->sudoku[$index]) && $this->sudoku[$index] == $item) |
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{ |
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$possible = false; |
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} |
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} |
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return $possible; |
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} |
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/** |
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* Determine if this item ok to place here |
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* |
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* @param $cell |
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* @param $item |
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* @return bool |
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*/ |
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private function is_possible_number($cell, $item) |
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{ |
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$row = $this->return_row($cell); |
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$col = $this->return_col($cell); |
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$block = $this->return_block($cell); |
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return ($this->is_possible_row($item, $row) && $this->is_possible_col($item, $col) && $this->is_possible_block($item, $block)); |
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} |
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/** |
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* Check if the row is unique |
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* |
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* @param int $row |
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* @return bool |
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*/ |
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private function is_correct_row($row) |
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{ |
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$row_temp = array(); |
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for ($x = 0; $x < $this->limit; $x++) |
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{ |
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if(!isset($this->sudoku[$row * $this->limit + $x])) |
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{ |
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$this->sudoku[$row * $this->limit + $x] = null; |
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} |
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$row_temp[$x] = $this->sudoku[$row * $this->limit + $x]; |
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} |
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return count(array_diff($this->chars, $row_temp)) == 0; |
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} |
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/** |
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* Check if the column is unique |
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* |
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* @param int $col |
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* @return bool |
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*/ |
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private function is_correct_col($col) |
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{ |
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$col_temp = array(); |
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for ($x = 0; $x < $this->limit; $x++) |
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{ |
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$col_temp[$x] = $this->sudoku[$col + $x * $this->limit]; |
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} |
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return count(array_diff($this->chars, $col_temp)) == 0; |
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} |
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/** |
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* Check if the block is unique |
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* |
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* @param int $block |
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* @return bool |
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*/ |
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private function is_correct_block($block) |
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{ |
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$block_temp = array(); |
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for ($x = 0; $x < $this->limit; $x++) |
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{ |
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$lookingfor = floor($block / $this->sq) * ($this->sq * $this->limit) + ($x % $this->sq) + $this->limit * floor($x / $this->sq) + $this->sq * ($block % $this->sq); |
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if (!isset($this->sudoku[$lookingfor])) |
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{ |
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$this->sudoku[$lookingfor] = null; |
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} |
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$block_temp[$x] = $this->sudoku[$lookingfor]; |
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} |
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return count(array_diff($this->chars, $block_temp)) == 0; |
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} |
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/** |
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* Determine if the sudoku is created successfully |
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* |
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* @return bool |
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*/ |
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private function is_solved_sudoku() |
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{ |
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for ($x = 0; $x < $this->limit; $x++) |
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{ |
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if (!$this->is_correct_block($x) or !$this->is_correct_row($x) or !$this->is_correct_col($x)) |
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{ |
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return false; |
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} |
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} |
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return true; |
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} |
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/** |
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* Find possible items |
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* |
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* @param int $cell |
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* @return array |
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*/ |
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private function determine_possible_values($cell) |
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{ |
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$possible = array(); |
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for ($x = 0; $x < $this->limit; $x++) |
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{ |
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if ($this->is_possible_number($cell, $this->chars[$x])) |
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{ |
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array_unshift($possible, $this->chars[$x]); |
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} |
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} |
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return $possible; |
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} |
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/** |
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* Random item from the possible item box |
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* |
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* @param array $possible |
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* @param int $cell |
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* @return string |
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*/ |
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private function determine_random_possible_value($possible, $cell) |
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{ |
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return $possible[$cell][rand(0, count($possible[$cell]) - 1)]; |
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} |
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/** |
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* Determine if everything goes well |
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* |
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* @return false|array |
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*/ |
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private function scan_sudoku_for_unique() |
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{ |
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$possible = false; |
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for ($x = 0; $x < $this->limit * $this->limit; $x++) |
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{ |
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if (!isset($this->sudoku[$x])) |
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{ |
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$possible[$x] = $this->determine_possible_values($x); |
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if (count($possible[$x]) == 0) |
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{ |
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return false; |
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} |
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} |
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} |
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return $possible; |
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} |
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302
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/** |
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303
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* Remove used item |
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304
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* |
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305
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* @param array $attempt_array |
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* @param string $item |
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* @return array |
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*/ |
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private function remove_attempt($attempt_array, $item) |
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{ |
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$new_array = array(); |
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$count = count($attempt_array); |
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for ($x = 0; $x < $count; $x++) |
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{ |
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if ($attempt_array[$x] != $item) |
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{ |
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array_unshift($new_array, $attempt_array[$x]); |
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} |
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} |
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return $new_array; |
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} |
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323
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/** |
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324
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* Next move |
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325
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* |
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326
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* @param $possible |
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327
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* @return int|null |
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328
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*/ |
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329
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private function next_random($possible) |
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330
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{ |
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331
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$min_choices = null; |
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332
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$max = $this->limit; |
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333
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for ($x = 0; $x < $this->limit * $this->limit; $x++) |
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334
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{ |
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335
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if (!isset($possible[$x])) |
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336
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{ |
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337
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$possible[$x] = null; |
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338
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} |
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339
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340
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if ((count($possible[$x]) <= $max) && (count($possible[$x]) > 0)) |
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341
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{ |
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342
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$max = count($possible[$x]); |
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343
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$min_choices = $x; |
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344
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} |
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345
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} |
|
346
|
|
|
return $min_choices; |
|
347
|
|
|
} |
|
348
|
|
|
|
|
349
|
|
|
/** |
|
350
|
|
|
* Basically prepares the variables we are going to use |
|
351
|
|
|
*/ |
|
352
|
|
|
private function build() |
|
353
|
|
|
{ |
|
354
|
|
|
$this->sudoku = array(); |
|
355
|
|
|
$this->chars = array(); |
|
356
|
|
|
|
|
357
|
|
|
for ($i = 0; $i < $this->limit; $i++) |
|
358
|
|
|
{ |
|
359
|
|
|
$this->chars[] = $this->stack[$i]; |
|
360
|
|
|
} |
|
361
|
|
|
} |
|
362
|
|
|
|
|
363
|
|
|
|
|
364
|
|
|
/** |
|
365
|
|
|
* Microtime to calculate time difference |
|
366
|
|
|
* |
|
367
|
|
|
* @return float |
|
368
|
|
|
*/ |
|
369
|
|
|
public function microtime() |
|
370
|
|
|
{ |
|
371
|
|
|
return microtime(true); |
|
372
|
|
|
} |
|
373
|
|
|
|
|
374
|
|
|
/** |
|
375
|
|
|
* Kickstarter function |
|
376
|
|
|
* |
|
377
|
|
|
* @param string $to |
|
378
|
|
|
* @return array|string |
|
379
|
|
|
*/ |
|
380
|
|
|
public function generate($to = 'json') |
|
381
|
|
|
{ |
|
382
|
|
|
$start = $this->microtime(); |
|
383
|
|
|
|
|
384
|
|
|
$this->build(); |
|
385
|
|
|
|
|
386
|
|
|
$x = 0; |
|
387
|
|
|
$saved = array(); |
|
388
|
|
|
$saved_sud = array(); |
|
389
|
|
|
while (!$this->is_solved_sudoku()) |
|
390
|
|
|
{ |
|
391
|
|
|
$x++; |
|
392
|
|
|
$scan = $this->scan_sudoku_for_unique(); |
|
393
|
|
|
|
|
394
|
|
|
if ($scan === false) |
|
395
|
|
|
{ |
|
396
|
|
|
$next_move = array_pop($saved); |
|
397
|
|
|
$this->sudoku = array_pop($saved_sud); |
|
398
|
|
|
} else { |
|
399
|
|
|
$next_move = (array) $scan; |
|
400
|
|
|
} |
|
401
|
|
|
|
|
402
|
|
|
$what_to_try = $this->next_random($next_move); |
|
403
|
|
|
$attempt = $this->determine_random_possible_value($next_move, $what_to_try); |
|
404
|
|
|
|
|
405
|
|
|
if (count($next_move[$what_to_try]) > 1) |
|
406
|
|
|
{ |
|
407
|
|
|
$next_move[$what_to_try] = $this->remove_attempt($next_move[$what_to_try], $attempt); |
|
408
|
|
|
array_push($saved, $next_move); |
|
409
|
|
|
array_push($saved_sud, $this->sudoku); |
|
410
|
|
|
} |
|
411
|
|
|
$this->sudoku[$what_to_try] = $attempt; |
|
412
|
|
|
} |
|
413
|
|
|
|
|
414
|
|
|
$timing = $this->microtime() - $start; |
|
415
|
|
|
$this->result = array( |
|
416
|
|
|
'created_in' => round($timing,2), |
|
417
|
|
|
'timestamp' => time(), |
|
418
|
|
|
'difficulty' => 'N/A' |
|
419
|
|
|
); |
|
420
|
|
|
|
|
421
|
|
|
return $this->to($to); |
|
422
|
|
|
} |
|
423
|
|
|
|
|
424
|
|
|
/** |
|
425
|
|
|
* Prepares the defaults of the returned value |
|
426
|
|
|
* |
|
427
|
|
|
* @return array |
|
428
|
|
|
*/ |
|
429
|
|
|
private function array2export() |
|
430
|
|
|
{ |
|
431
|
|
|
return array( |
|
432
|
|
|
'sudoku' => $this->sudoku, |
|
433
|
|
|
'limit' => $this->limit, |
|
434
|
|
|
'result' => $this->result, |
|
435
|
|
|
); |
|
436
|
|
|
} |
|
437
|
|
|
|
|
438
|
|
|
/** |
|
439
|
|
|
* Return type. JSON, SERIALIZED or an ARRAY |
|
440
|
|
|
* |
|
441
|
|
|
* @param string $to |
|
442
|
|
|
* @return array|string |
|
443
|
|
|
*/ |
|
444
|
|
|
public function to($to) |
|
445
|
|
|
{ |
|
446
|
|
|
|
|
447
|
|
|
if($to == 'json') |
|
448
|
|
|
{ |
|
449
|
|
|
return json_encode($this->array2export()); |
|
450
|
|
|
} |
|
451
|
|
|
else if($to == 'serialize') |
|
452
|
|
|
{ |
|
453
|
|
|
return serialize($this->array2export()); |
|
454
|
|
|
} |
|
455
|
|
|
// else if($to == 'array') |
|
456
|
|
|
return (array) $this->array2export(); |
|
457
|
|
|
} |
|
458
|
|
|
} |