地图几个相邻节点求出 $start 到 $end 的最短路径【算法】

来源：互联网发布：it运维管理大数据编辑：程序博客网时间：2024/06/06 18:18

方法一：(找到最短路径就跳出有限制不推荐)

<?PHP$maps = [            // 点    // 相邻节点列表            1001 => [1002,1003,1005,1008,1009],            1002 => [1001,1008],            1003 => [1001,1005,1009],            1005 => [1001,1003,1004,1009],            1008 => [1001,1002,1009],            1009 => [1001,1003,1004,1005,1007,1008],            1004 => [1005,1009],            1007 => [1009]        ];$obj = new parse($maps);$obj->find('1002', '1007');echo $obj->getBest();class parse{    var $data = array();    var $used = array();    var $chain = array();    function parse($data){        $this->data = $data;    }    /**     * $start 开始节点     * $end   结束节点     * $chain 当前查找路线的经过节点     */    function find($start, $end, $chain=array()){        //将起始节点加入当前朋友链中        $chain[] = $start;        //判断当前起点是否有朋友        if(!isset($this->data[$start]))            return;        //判断当前的起点是否认识终点        if(in_array($end, $this->data[$start])){            $chain[] = $end;            $this->chain = $chain;            return ;        }        //如果当前"未完成路径" 比 "目前的最优路径" 长, 停止当前循环        if(sizeof($chain)>=sizeof($this->chain) && sizeof($this->chain)!=0)            return;        //继续递归循环        foreach($this->data[$start] as $value)            if(!in_array($value, $chain))                $this->find($value, $end, $chain);    }    function getBest(){        $str = implode('->', $this->chain);        return $str==null? "can't relation": $str;    }}?>

方法二:(找到所有路径，自己选择推荐)

<?PHP$maps = [            // 点    // 相邻节点列表            1001 => [1002,1003,1005,1008,1009],            1002 => [1001,1008],            1003 => [1001,1005,1009],            1005 => [1001,1003,1004,1009],            1008 => [1001,1002,1009],            1009 => [1001,1003,1004,1005,1007,1008],            1004 => [1005,1009],            1007 => [1009]        ];$obj = new parse($maps);$obj->find(1002, 1007);class parse{    var $data = array();    function parse($data){        $this->data = $data;    }    /**     * $start 开始节点     * $end   结束节点     * $chain 当前查找路线的经过节点     */    function find($start, $end, $chain=array()){        //将起始节点加入当前节点链中        $chain[] = $start;        //判断当前起点是否有相邻节点        if(!isset($this->data[$start]))            return;        //判断当前的起点是否是终点的相邻节点        if(in_array($end, $this->data[$start])){            echo implode('->', $chain)."->$end".'<br/>';            return ;        }        //继续递归循环        foreach($this->data[$start] as $value)            if(!in_array($value, $chain))                $this->find($value, $end, $chain);    }}?>

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