PHP实现克鲁斯卡尔算法实例解析

php  /  管理员 发布于 7年前   140

本文实例展示了PHP实现的格鲁斯卡尔算法（kruscal）的实现方法，分享给大家供大家参考。相信对于大家的PHP程序设计有一定的借鉴价值。

具体代码如下：

 '10',  'af' => '11',  'gb' => '16',  'fg' => '17',  'bc' => '18',  'bi' => '12',  'ci' => '8',  'cd' => '22',  'di' => '21',  'dg' => '24',  'gh' => '19',  'dh' => '16',  'de' => '20',  'eh' => '7',  'fe' => '26');$test = new Edge($a, $b);print_r($test->kruscal());?>

edge.php文件代码如下：

begin = $begin;    $this->end = $end;    $this->weight = $weight;  }  public function getBegin() {    return $this->begin;  }  public function getEnd() {    return $this->end;  }  public function getWeight() {    return $this->weight;  }}class Edge {  //边集数组实现图  private $vexs; //顶点集合  private $arc; //边集合  private $arcData; //要构建图的边信息  private $krus; //kruscal算法时存放森林信息  public function Edge($vexsData, $arcData) {    $this->vexs = $vexsData;    $this->arcData = $arcData;    $this->createArc();  }  //创建边  private function createArc() {    foreach ($this->arcData as $key => $value) {      $key = str_split($key);      $this->arc[] = new EdgeArc($key[0], $key[1], $value);    }  }  //对边数组按权值排序  public function sortArc() {    $this->quicklySort(0, count($this->arc) - 1, $this->arc);    return $this->arc;  }  //采用快排  private function quicklySort($begin, $end, &$item) {    if ($begin < 0($begin >= $end)) return;    $key = $this->excuteSort($begin, $end, $item);    $this->quicklySort(0, $key - 1, $item);    $this->quicklySort($key + 1, $end, $item);  }  private function excuteSort($begin, $end, &$item) {    $key = $item[$begin];    $left = array();    $right = array();    for ($i = ($begin + 1); $i <= $end; $i++) {      if ($item[$i]->getWeight() <= $key->getWeight()) {        $left[] = $item[$i];      } else {        $right[] = $item[$i];      }    }    $return = $this->unio($left, $right, $key);    $k = 0;    for ($i = $begin; $i <= $end; $i++) {      $item[$i] = $return[$k];      $k++;    }    return $begin + count($left);  }  private function unio($left, $right, $key) {    return array_merge($left, array(      $key    ) , $right);  }  //kruscal算法  public function kruscal() {    $this->krus = array();    $this->sortArc();    foreach ($this->vexs as $value) {      $this->krus[$value] = "0";    }    foreach ($this->arc as $key => $value) {      $begin = $this->findRoot($value->getBegin());      $end = $this->findRoot($value->getEnd());      if ($begin != $end) {        $this->krus[$begin] = $end;        echo $value->getBegin() . "-" . $value->getEnd() . ":" . $value->getWeight() . "\n";      }    }  }  //查找子树的尾结点  private function findRoot($node) {    while ($this->krus[$node] != "0") {      $node = $this->krus[$node];    }    return $node;  }}?> 

感兴趣的读者可以调试运行一下本文克鲁斯卡尔算法实例，相信会有新的收获。

您可能感兴趣的文章:

• PHP实现通过Luhn算法校验信用卡卡号是否有效
• php约瑟夫问题解决关于处死犯人的算法
• PHP贪婪算法解决0-1背包问题实例分析
• PHP树的深度编历生成迷宫及A*自动寻路算法实例分析
• php计算两个整数的最大公约数常用算法小结
• PHP冒泡算法详解（递归实现）
• PHP大转盘中奖概率算法实例
• php实现的常见排序算法汇总
• php实现猴子选大王问题算法实例