67 lines
1.7 KiB
PHP
67 lines
1.7 KiB
PHP
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<?php
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namespace Graphp\Algorithms;
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use Graphp\Algorithms\BaseGraph;
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use Fhaculty\Graph\Edge\Directed as EdgeDirected;
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use Fhaculty\Graph\Edge\Undirected as EdgeUndirected;
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/**
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* Basic algorithms for working with the undirected or directed Graphs (digraphs) / Walks.
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*
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* @link http://en.wikipedia.org/wiki/Glossary_of_graph_theory#Direction
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* @link http://en.wikipedia.org/wiki/Digraph_%28mathematics%29
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*/
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class Directed extends BaseDual
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{
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/**
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* checks whether the graph has any directed edges
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*
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* This method is intentionally not named "isDirected()" (aka digraph),
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* because that might be misleading in regards to empty and/or mixed graphs.
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*
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* @return boolean
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*/
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public function hasDirected()
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{
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foreach ($this->set->getEdges() as $edge) {
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if ($edge instanceof EdgeDirected) {
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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 the graph has any undirected edges
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*
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* This method is intentionally not named "isUndirected()",
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* because that might be misleading in regards to empty and/or mixed graphs.
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*
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* @return boolean
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*/
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public function hasUndirected()
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{
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foreach ($this->set->getEdges() as $edge) {
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if ($edge instanceof EdgeUndirected) {
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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 is a mixed graph (contains both directed and undirected edges)
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*
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* @return boolean
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* @uses self::hasDirected()
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* @uses self::hasUndirected()
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*/
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public function isMixed()
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{
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return ($this->hasDirected() && $this->hasUndirected());
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}
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}
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