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<?php |
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namespace Letournel\PathFinder\Algorithms\TravelingSalesman; |
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use Letournel\PathFinder\AlgorithmTravelingSalesman; |
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use Letournel\PathFinder\Core\Node; |
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use Letournel\PathFinder\Core\NodeGraph; |
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use Letournel\PathFinder\Core\NodePath; |
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class TwoOpt implements AlgorithmTravelingSalesman |
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{ |
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/* |
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* For more info see |
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* http://en.wikipedia.org/wiki/2-opt |
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*/ |
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private |
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$existingRoute, |
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$graph; |
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public function setExistingRoute(NodePath $existingRoute) |
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{ |
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$this->existingRoute = $existingRoute; |
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} |
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public function setGraph(NodeGraph $graph) |
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{ |
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$this->graph = $graph; |
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} |
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public function computeRoute() |
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{ |
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if(! $this->graph instanceof NodeGraph) |
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{ |
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throw new \RuntimeException('Invalid Graph'); |
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} |
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if(! $this->existingRoute instanceof NodePath) |
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{ |
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throw new \RuntimeException('Invalid ExistingRoute'); |
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} |
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if(count($this->existingRoute) < 2) |
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{ |
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return $this->existingRoute; |
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} |
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$existingDistance = $this->graph->computeLength($this->existingRoute); |
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do |
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{ |
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$improvementMade = false; |
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foreach($this->existingRoute->getKeys() as $iKey) |
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{ |
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foreach($this->existingRoute->getKeys() as $kKey) |
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{ |
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if($iKey == $kKey) |
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{ |
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continue; |
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} |
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$newRoute = $this->twoOptSwap($iKey, $kKey); |
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$newDistance = $this->graph->computeLength($newRoute); |
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View Code Duplication |
if($newDistance < $existingDistance) |
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{ |
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$this->existingRoute = $newRoute; |
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$existingDistance = $newDistance; |
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$improvementMade = true; |
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break 2; |
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} |
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} |
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} |
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} while($improvementMade); |
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return $this->existingRoute; |
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} |
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private function twoOptSwap($iKey, $kKey) |
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{ |
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$newRouteNodes = array(); |
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foreach($this->existingRoute->getKeys() as $key) |
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{ |
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if ($key === $iKey) |
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{ |
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$newRouteNodes[] = $this->existingRoute->getKey($kKey); |
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} |
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elseif($key === $kKey) |
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{ |
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$newRouteNodes[] = $this->existingRoute->getKey($iKey); |
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} |
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else |
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{ |
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$newRouteNodes[] = $this->existingRoute->getKey($key); |
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} |
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} |
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return new NodePath($newRouteNodes); |
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} |
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} |
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letournel /
path-finder
Loading history...
Only declaring a single property per statement allows you to later on add doc comments more easily.
It is also recommended by PSR2, so it is a common style that many people expect.