PHP实现链表的定义与反转功能示例

<?phpclass Node{  private $Data;//节点数据  private $Next;//下一节点   public function setData($value){    $this->Data=$value;  }   public function setNext($value){     $this->Next=$value;  }     public function getData(){    return $this->Data;  }   public function getNext(){    return $this->Next;  }   public function __construct($data,$next){    $this->setData($data);    $this->setNext($next);  }}class LinkList{  private $header;//头节点  private $size;//长度  public function getSize() {    $i=0;    $node=$this->header;    while($node->getNext()!=null)    {    $i++;      $node=$node->getNext();    }    return $i;  }   public function setHeader($value){    $this->header=$value;  }   public function getHeader(){    return $this->header;  }   public function __construct(){    header("content-type:text/html; charset=utf-8");    $this->setHeader(new Node(null,null));  }  /**  *@author MzXy  *@param $data--要添加节点的数据  *   */  public function add($data)  {    $node=$this->header;    while($node->getNext()!=null)    {      $node=$node->getNext();    }    $node->setNext(new Node($data,null));  }   /**  *@author MzXy  *@param $data--要移除节点的数据  *   */  public function removeAt($data)  {    $node=$this->header;    while($node->getData()!=$data)    {      $node=$node->getNext();    }    $node->setNext($node->getNext());    $node->setData($node->getNext()->getData());  }   /**  *@author MzXy  *@param 遍历  *   */  public function get()  {    $node=$this->header;    if($node->getNext()==null){      print("数据集为空!");      return;    }    while($node->getNext()!=null)    {      print('['.$node->getNext()->getData().'] -> ');      if($node->getNext()->getNext()==null){break;}      $node=$node->getNext();    }  }   /**  *@author MzXy  *@param $data--要访问的节点的数据  * @param 此方法只是演示不具有实际意义  *   */  public function getAt($data)  {    $node=$this->header->getNext();  if($node->getNext()==null){      print("数据集为空!");      return;    }    while($node->getData()!=$data)    {      if($node->getNext()==null){break;}      $node=$node->getNext();    }    return $node->getData();      }   /**  *@author MzXy  *@param $value--需要更新的节点的原数据 --$initial---更新后的数据  *   */  public function update($initial,$value)  {     $node=$this->header->getNext(); if($node->getNext()==null){     print("数据集为空!");      return;    }    while($node->getData()!=$data)    {      if($node->getNext()==null){break;}      $node=$node->getNext();    } $node->setData($initial);     }}$lists = new LinkList();$lists -> add(1);$lists -> add(2);$lists -> get();echo '<pre>';print_r($lists);echo '</pre>';?>

function ReverseList($pHead){  // write code here  if($pHead == null || $pHead->next == null){    return $pHead;  }  $p = $pHead;  $q = $pHead->next;  $pHead->next = null;//$pHead 变为尾指针  while($q){    $r = $q->next;    $q->next = $p;    $p = $q;    $q = $r;  }  return $p;}

function ReverseList($pHead){  // write code here  if($pHead == null || $pHead->next == null){    return $pHead;  }  $res = ReverseList($pHead->next);  $pHead->next->next = $pHead;  $pHead->next = null;  return $res;}