|
1
|
|
|
<?php declare(strict_types=1); |
|
2
|
|
|
|
|
3
|
|
|
namespace Stratadox\PuzzleSolver\Solver; |
|
4
|
|
|
|
|
5
|
|
|
use Stratadox\PuzzleSolver\Puzzle; |
|
6
|
|
|
use Stratadox\PuzzleSolver\PuzzleSolver; |
|
7
|
|
|
use Stratadox\PuzzleSolver\NoPossibleSolution; |
|
8
|
|
|
use Stratadox\PuzzleSolver\PuzzleSolution; |
|
9
|
|
|
use Stratadox\PuzzleSolver\SearchStrategy\SearchStrategyFactory; |
|
10
|
|
|
use Stratadox\PuzzleSolver\Solutions; |
|
11
|
|
|
|
|
12
|
|
|
/** |
|
13
|
|
|
* Eager puzzle solvers will search for the first valid solution. Eager solvers |
|
14
|
|
|
* will stop after finding a single solution, making them neat for puzzles that |
|
15
|
|
|
* can have only one possible solution, or require only a single solution. |
|
16
|
|
|
* |
|
17
|
|
|
* @author Stratadox |
|
18
|
|
|
*/ |
|
19
|
|
|
final class EagerSolver implements PuzzleSolver |
|
20
|
|
|
{ |
|
21
|
|
|
/** @var SearchStrategyFactory */ |
|
22
|
|
|
private $strategy; |
|
23
|
|
|
|
|
24
|
|
|
private function __construct(SearchStrategyFactory $strategy) |
|
25
|
|
|
{ |
|
26
|
|
|
$this->strategy = $strategy; |
|
27
|
|
|
} |
|
28
|
|
|
|
|
29
|
|
|
public static function using(SearchStrategyFactory $strategy): PuzzleSolver |
|
30
|
|
|
{ |
|
31
|
|
|
return new self($strategy); |
|
32
|
|
|
} |
|
33
|
|
|
|
|
34
|
|
|
public function solve(Puzzle $puzzle): Solutions |
|
35
|
|
|
{ |
|
36
|
|
|
$search = $this->strategy->begin($puzzle); |
|
37
|
|
|
|
|
38
|
|
|
while ($search->isOngoing()) { |
|
39
|
|
|
$puzzleState = $search->nextCandidate(); |
|
40
|
|
|
|
|
41
|
|
|
if ($puzzleState->isSolved()) { |
|
42
|
|
|
return new Solutions(PuzzleSolution::fromSolved($puzzleState, $puzzle)); |
|
43
|
|
|
} |
|
44
|
|
|
|
|
45
|
|
|
foreach ($puzzleState->possibleMoves() as $move) { |
|
46
|
|
|
$search->consider($puzzleState->afterMaking($move)); |
|
47
|
|
|
} |
|
48
|
|
|
} |
|
49
|
|
|
|
|
50
|
|
|
throw NoPossibleSolution::to($puzzle); |
|
51
|
|
|
} |
|
52
|
|
|
} |
|
53
|
|
|
|
Stratadox /
PuzzleSolver
