phpOMS/Math/Optimization/TSP/BruteForce.php

119 lines
2.7 KiB
PHP

<?php
/**
* Orange Management
*
* PHP Version 7.0
*
* @category TBD
* @package TBD
* @author OMS Development Team <dev@oms.com>
* @author Dennis Eichhorn <d.eichhorn@oms.com>
* @copyright 2013 Dennis Eichhorn
* @license OMS License 1.0
* @version 1.0.0
* @link http://orange-management.com
*/
namespace phpOMS\Math\Optimization\TSP;
/**
* TSP solution with brute force.
*
* @category Framework
* @package phpOMS\DataStorage\Database
* @author OMS Development Team <dev@oms.com>
* @author Dennis Eichhorn <d.eichhorn@oms.com>
* @license OMS License 1.0
* @link http://orange-management.com
* @since 1.0.0
*/
class BruteForce
{
/**
* City limit (for factorial calculation).
*
* @var float
* @since 1.0.0
*/
const LIMIT = 22;
/**
* City pool.
*
* @var CityPool
* @since 1.0.0
*/
private $cityPool = null;
/**
* Constructor.
*
* @param CityPool $pool City pool
*
* @throws
*
* @since 1.0.0
* @author Dennis Eichhorn <d.eichhorn@oms.com>
*/
public function __construct(CityPool $pool)
{
$this->cityPool = $pool;
if ($this->cityPool->count() > self::LIMIT) {
throw new \Exception('Overflow');
}
}
/**
* Calculate best routes.
*
* @param int $limit Amount of best routes
*
* @return Population
*
* @since 1.0.0
* @author Dennis Eichhorn <d.eichhorn@oms.com>
*/
public function getSolution(int $limit = 1) : Population
{
$population = new Population($this->cityPool, $limit, true);
$cities = $this->cityPool->getCities();
$this->bruteForce($cities, new Tour($this->cityPool, false), $population);
return $population;
}
/**
* Bruteforce best solutions.
*
* @param array $cities Cities
* @param Tour $tour Current (potential) optimal tour
* @param Population $population Population of tours
*
* @return Population
*
* @since 1.0.0
* @author Dennis Eichhorn <d.eichhorn@oms.com>
*/
private function bruteForce(array $cities, Tour $tour, Population $population)
{
if (empty($cities)) {
$population->addTour($tour);
}
$count = count($cities);
for ($i = 0; $i < $count; $i++) {
$extended = clone $tour;
$extended->addCity($cities[$i]);
unset($cities[$i]);
if ($population->getUnfittest()->getFitness() > $extended->getFitness()) {
continue;
}
$this->bruteForce($cities, $extended, $population);
}
}
}