45 lines
1.0 KiB
PHP
45 lines
1.0 KiB
PHP
<?php
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namespace Graphp\Algorithms\Tree;
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use Graphp\Algorithms\Tree\BaseDirected as DirectedTree;
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use Fhaculty\Graph\Exception\UnexpectedValueException;
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use Fhaculty\Graph\Vertex;
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/**
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* Alternative InTree implementation where Edges "point towards" root Vertex
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*
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* ROOT
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* ^ ^
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* / \
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* A B
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* ^
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* \
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* C
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*
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* @link http://en.wikipedia.org/wiki/Spaghetti_stack
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* @see DirectedTree for more information on directed, rooted trees
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*/
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class InTree extends DirectedTree
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{
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public function getVerticesChildren(Vertex $vertex)
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{
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$vertices = $vertex->getVerticesEdgeFrom();
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if ($vertices->hasDuplicates()) {
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throw new UnexpectedValueException();
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}
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return $vertices;
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}
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protected function getVerticesParent(Vertex $vertex)
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{
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$vertices = $vertex->getVerticesEdgeTo();
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if ($vertices->hasDuplicates()) {
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throw new UnexpectedValueException();
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}
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return $vertices;
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}
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}
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