106 lines
2.1 KiB
Plaintext
106 lines
2.1 KiB
Plaintext
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import 'math';
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class Sudoku {
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public int[] $board;
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int $size;
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public void __construct(int[] $board) {
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$this->board = $board;
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$this->size = sizeof($this->board);
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}
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public bool isSafe(int $row, int $col, int $n) {
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for(int $d = 0; $d < $this->size; $d++) {
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if($this->board[$row][$d] == $n) {
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return false;
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}
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}
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for(int $r = 0; $r < $this->size; $r++) {
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if($this->board[$r][$col] == $n) {
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return false;
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}
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}
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int $sqrt = (int) sqrt($this->size);
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int $boxRowStart = $row - $row % $sqrt;
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int $boxColStart = $col - $col % $sqrt;
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for(int $w = $boxRowStart; $w < $boxRowStart + $sqrt; $w++) {
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for(int $q = $boxColStart; $q < $boxColStart + $sqrt; $q++) {
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if($this->board[$w][$q] == $n) {
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return false;
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}
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}
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}
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return true;
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}
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public void print() {
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for(int $r = 0; $r < $this->size; $r++) {
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for(int $d = 0; $d < $this->size; $d++) {
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print($this->board[$r][$d] + " ");
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}
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print("\n");
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}
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}
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public bool solve() {
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int $row = -1;
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int $col = -1;
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bool $isEmpty = true;
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for(int $i = 0; $i < $this->size; $i++) {
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for(int $j = 0; $j < $this->size; $j++) {
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if($this->board[$i][$j] == 0) {
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$row = $i;
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$col = $j;
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$isEmpty = false;
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break;
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}
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}
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if(!$isEmpty) {
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break;
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}
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}
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if($isEmpty) {
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return true;
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}
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for(int $n = 1; $n <= $this->size; $n++) {
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if($this->isSafe($row, $col, $n)) {
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$this->board[$row][$col] = $n;
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if($this->solve()) {
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return true;
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} else {
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$this->board[$row][$col] = 0;
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}
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}
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}
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return false;
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}
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}
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class Program {
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void main() {
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int[] $board = {
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{3, 0, 6, 5, 0, 8, 4, 0, 0},
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{5, 2, 0, 0, 0, 0, 0, 0, 0},
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{0, 8, 7, 0, 0, 0, 0, 3, 1},
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{0, 0, 3, 0, 1, 0, 0, 8, 0},
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{9, 0, 0, 8, 6, 3, 0, 0, 5},
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{0, 5, 0, 0, 9, 0, 6, 0, 0},
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{1, 3, 0, 0, 0, 0, 2, 5, 0},
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{0, 0, 0, 0, 0, 0, 0, 7, 4},
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{0, 0, 5, 2, 0, 6, 3, 0, 0}
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};
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object $sudoku = new Sudoku($board);
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$sudoku->print();
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print("=================\n");
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if($sudoku->solve()) {
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$sudoku->print();
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} else {
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print("No solution found\n");
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$sudoku->print();
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}
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}
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}
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