53 lines
1.1 KiB
PHP
53 lines
1.1 KiB
PHP
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<?php
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namespace Graphp\Algorithms;
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use Graphp\Algorithms\BaseDual;
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use Fhaculty\Graph\Edge\Base as Edge;
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use Fhaculty\Graph\Vertex;
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/**
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* Basic algorithms for working with loop edges
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*
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* A loop (also called a self-loop or a "buckle") is an edge that connects a
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* Vertex to itself. A simple graph contains no loops.
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*
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* @link http://en.wikipedia.org/wiki/Loop_%28graph_theory%29
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*/
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class Loop extends BaseDual
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{
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/**
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* checks whether this graph has any loops (edges from vertex to itself)
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*
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* @return boolean
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* @uses Edge::isLoop()
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*/
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public function hasLoop()
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{
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foreach ($this->set->getEdges() as $edge) {
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if ($edge->isLoop()) {
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return true;
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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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* checks whether this vertex has a loop (edge to itself)
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*
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* @return boolean
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* @uses Edge::isLoop()
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*/
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public function hasLoopVertex(Vertex $vertex)
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{
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foreach ($vertex->getEdges() as $edge) {
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if ($edge->isLoop()) {
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return true;
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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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