|
1
|
|
|
<?php declare(strict_types=1); |
|
2
|
|
|
|
|
3
|
|
|
namespace Stratadox\PuzzleSolver\Puzzle\Sudoku; |
|
4
|
|
|
|
|
5
|
|
|
use Stratadox\PuzzleSolver\Moves; |
|
6
|
|
|
use function assert; |
|
7
|
|
|
|
|
8
|
|
|
final class Sudoku |
|
9
|
|
|
{ |
|
10
|
|
|
/** @var int[][]|null[][] */ |
|
11
|
|
|
private $numbers; |
|
12
|
|
|
/** @var bool[][] */ |
|
13
|
|
|
private $rows = []; |
|
14
|
|
|
/** @var bool[][] */ |
|
15
|
|
|
private $cols = []; |
|
16
|
|
|
/** @var bool[][][] */ |
|
17
|
|
|
private $boxes = []; |
|
18
|
|
|
/** @var int[]|null */ |
|
19
|
|
|
private $firstEmptyPosition; |
|
20
|
|
|
|
|
21
|
|
|
public function __construct(array ...$numbers) |
|
22
|
|
|
{ |
|
23
|
|
|
$this->numbers = $numbers; |
|
24
|
|
|
foreach ($numbers as $r => $row) { |
|
25
|
|
|
foreach ($row as $c => $number) { |
|
26
|
|
|
if (null !== $number) { |
|
27
|
|
|
$this->rows[$r][$number] = true; |
|
28
|
|
|
$this->cols[$c][$number] = true; |
|
29
|
|
|
$this->boxes[$r / 3][$c / 3][$number] = true; |
|
30
|
|
|
} elseif (null === $this->firstEmptyPosition) { |
|
31
|
|
|
$this->firstEmptyPosition = [$r, $c]; |
|
32
|
|
|
} |
|
33
|
|
|
} |
|
34
|
|
|
} |
|
35
|
|
|
} |
|
36
|
|
|
|
|
37
|
|
|
public function isFull(): bool |
|
38
|
|
|
{ |
|
39
|
|
|
return null === $this->firstEmptyPosition; |
|
40
|
|
|
} |
|
41
|
|
|
|
|
42
|
|
|
public function possibilitiesForNextEmptyPosition(): Moves |
|
43
|
|
|
{ |
|
44
|
|
|
if (null === $this->firstEmptyPosition) { |
|
45
|
|
|
return Moves::none(); |
|
46
|
|
|
} |
|
47
|
|
|
[$r, $c] = $this->firstEmptyPosition; |
|
48
|
|
|
return Entry::allPossibilitiesFor($r, $c)->filterWith(function (Entry $entry) { |
|
|
|
|
|
|
49
|
|
|
return $this->allows($entry); |
|
50
|
|
|
}); |
|
51
|
|
|
} |
|
52
|
|
|
|
|
53
|
|
|
// For immutable sudoku puzzle implementations |
|
54
|
|
|
public function withFilledIn(Entry ...$entries): self |
|
55
|
|
|
{ |
|
56
|
|
|
$numbers = $this->numbers; |
|
57
|
|
|
foreach ($entries as $entry) { |
|
58
|
|
|
assert($this->allows($entry)); |
|
59
|
|
|
$numbers[$entry->row()][$entry->column()] = $entry->number(); |
|
60
|
|
|
} |
|
61
|
|
|
return new self(...$numbers); |
|
62
|
|
|
} |
|
63
|
|
|
|
|
64
|
|
|
public function __toString(): string |
|
65
|
|
|
{ |
|
66
|
|
|
$sudoku = "\n+-------+-------+-------+ \n"; |
|
67
|
|
|
foreach ($this->numbers as $r => $row) { |
|
68
|
|
|
$sudoku .= '| '; |
|
69
|
|
|
foreach ($row as $c => $value) { |
|
70
|
|
|
$sudoku .= ($value ?: ' ') . ' '; |
|
71
|
|
|
if ($c % 3 === 2) { |
|
72
|
|
|
$sudoku .= '| '; |
|
73
|
|
|
} |
|
74
|
|
|
} |
|
75
|
|
|
$sudoku .= "\n"; |
|
76
|
|
|
if ($r % 3 === 2) { |
|
77
|
|
|
$sudoku .= "+-------+-------+-------+ \n"; |
|
78
|
|
|
} |
|
79
|
|
|
} |
|
80
|
|
|
return $sudoku; |
|
81
|
|
|
} |
|
82
|
|
|
|
|
83
|
|
|
private function allows(Entry $entry): bool |
|
84
|
|
|
{ |
|
85
|
|
|
return null === $this->numbers[$entry->row()][$entry->column()] |
|
86
|
|
|
&& $this->canAddInRow($entry->row(), $entry->number()) |
|
87
|
|
|
&& $this->canAddInColumn($entry->column(), $entry->number()) |
|
88
|
|
|
&& $this->canAddInRegion($entry->row(), $entry->column(), $entry->number()); |
|
89
|
|
|
} |
|
90
|
|
|
|
|
91
|
|
|
private function canAddInRow(int $row, int $number): bool |
|
92
|
|
|
{ |
|
93
|
|
|
return !isset($this->rows[$row][$number]); |
|
94
|
|
|
} |
|
95
|
|
|
|
|
96
|
|
|
private function canAddInColumn(int $column, int $number): bool |
|
97
|
|
|
{ |
|
98
|
|
|
return !isset($this->cols[$column][$number]); |
|
99
|
|
|
} |
|
100
|
|
|
|
|
101
|
|
|
private function canAddInRegion(int $row, int $column, int $number): bool |
|
102
|
|
|
{ |
|
103
|
|
|
return !isset($this->boxes[$row / 3][$column / 3][$number]); |
|
104
|
|
|
} |
|
105
|
|
|
} |
|
106
|
|
|
|
Stratadox /
PuzzleSolver
Loading history...