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<?php |
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namespace Algorithms; |
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class Dijkstra |
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{ |
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protected $points; |
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protected $relations; |
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public function __construct($relations = NULL) |
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{ |
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if (!empty($relations)) { |
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$this->setRelations($relations); |
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} |
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} |
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public function setRelations($relations) |
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{ |
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if (self::validate($relations)) { |
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$this->relations = $relations; |
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} else { |
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if (is_callable($relations) && ($relations instanceof \Closure)) { |
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$creator = new GraphTools\Creator; |
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call_user_func($relations, $creator); |
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$this->relations = $creator->createConnections(); |
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} |
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} |
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} |
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public function generate() |
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{ |
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$result = []; # Prepare results array |
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# Analyze all relations |
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foreach ($this->relations as $point => $relation) { |
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# Prepare $points array by isset source point |
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$this->points = [ |
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$point => [ |
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0, |
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'', |
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], |
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]; |
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$this->dist($point, $point); |
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$result[$point] = $this->points; # Copy $points content to results array |
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} |
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return $result; |
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} |
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private function dist($source, $point, &$visited = []) |
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{ |
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$visited[$point] = TRUE; # Set current point as visited |
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# Prepare help variables |
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$min_ptr = -1; |
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$min = 0; |
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# Analyzes point neighborhood |
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foreach ($this->relations[$point] as $relation) { |
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if ($relation[0] != $source) { # If current point is different than source |
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if (empty($visited[$relation[0]])) { # If current point is not visited |
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if ($min_ptr == -1) { # When minimal point is not finded |
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$min_ptr = $relation[0]; |
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$min = $relation[1]; |
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} else { |
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if ($min > $relation[1]) { |
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$min_ptr = $relation[0]; |
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$min = $relation[1]; |
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} |
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} |
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} |
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# Change the shortest way to current point |
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if (isset($this->points[$point][0])) { |
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$first_field = $this->points[$point][0]; |
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} else { |
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$first_field = 0; |
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} |
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if (empty($this->points[$relation[0]])) { |
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$this->points[$relation[0]] = [ |
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$first_field + $relation[1], |
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((empty($this->points[$point][1])) ? $point : $this->points[$point][1]) . ':' . $relation[0], |
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]; |
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} else { |
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if ($this->points[$relation[0]][0] > ($this->points[$point][0] + $relation[1])) { |
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$this->points[$relation[0]] = [ |
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((isset($this->points[$point][0])) ? $this->points[$point][0] : 0) + $relation[1], |
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((empty($this->points[$point][1])) ? NULL : $this->points[$point][1] . ':') . $relation[0], |
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]; |
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} |
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} |
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} |
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} |
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# If isset unvisited point with minimal way go for it |
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if ($min_ptr != -1) { |
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$this->dist($source, $min_ptr, $visited); |
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} |
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} |
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public function distances($point) |
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{ |
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$this->dist($point, $point); |
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return $this->points; |
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} |
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private static function validate($relations_array) |
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{ |
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if (is_array($relations_array)) { |
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$return = TRUE; |
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foreach ($relations_array as $relations) { |
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if (is_array($relations)) { |
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foreach ($relations as $relation) { |
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if (!(is_array($relation) && (count($relation) == 2) && isset($relation[0]) && isset($relation[1]))) { |
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$return = FALSE; |
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break; |
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} |
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} |
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if ($return === FALSE) { |
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break; |
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} |
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} else { |
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$return = FALSE; |
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break; |
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} |
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} |
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return $return; |
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} else { |
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return FALSE; |
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} |
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} |
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} |
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PHPAlgorithms /
Dijkstra-s-algorithm
