php循环链表的实现

我编写这个类是为了实现链表：

class Node{
    public $data;
    public $link;

    function __construct($data, $next = NULL){
        $this->data = $data;
        $this->link = $next;
    }    
}

class CircularLinkedList{
    private $first;
    private $current;
    private $count;

    function __construct(){
        $this->count = 0;
        $this->first = null;
        $this->current = null;
    }

    function isEmpty(){
        return ($this->first == NULL);
    }

    function push($data){
        //line 30
        $p = new Node($data, $this->first);
        if($this->isEmpty()){
            $this->first = $p;
            $this->current = $this->first;
        }
        else{           
            $q = $this->first;
            //line 38
            while($q->link != $this->first)
                $q = $q->link;
            $q->link = $p;    
        }
        $this->count++;       
    }

    function find($value){
        $q = $this->first;
        while($q->link != null){
            if($q->data == $value)
                $this->current = $q;
            $q = $q->link;    
        }
        return false;      
    }

    function getNext(){
        $result = $this->current->data;
        $this->current = $this->current->link;
        return $result;        
    }
}  

function push($data){
    $p = new Node($data);
    if($this->isEmpty()){
        $this->first = $p;
        $this->current = $this->first;
    }
    else{
        $q = $this->first;
        while($q->link != null)
            $q = $q->link;
        $q->link = $p;    
    }
    $this->count++;       
}

但当我试图推动一些价值时

$ll = new CircularLinkedList();

$ll->push(5);
$ll->push(6);
$ll->push(7);
$ll->push(8);
$ll->push(9);
$ll->push(10);

//$ll->find(7);

for($j=0;$j<=30;$j++){
    $result = $ll->getNext();
    echo $result."<br />";
}

---

对于线性链表-更改以下内容：

      function push($data){

       if($this->isEmpty()){
         $this->first   = new Node($data);
         $this->current = $this->first;
         $this->count++;
       }
       else{

        $this->current->link = new Node($data);
        $this->current = $this->current->link;
        $this->count++;

      }

    }

这种结构产生：

    CircularLinkedList Object
    (
      [first:CircularLinkedList:private] => Node Object
      (
        [data] => 2
        [link] => Node Object
            (
                [data] => 10
                [link] => Node Object
                    (
                        [data] => 3
                        [link] => Node Object
                            (
                                [data] => 9
                                [link] => 
                            )

                    )

            )

    )

    [current:CircularLinkedList:private] => Node Object
    (
        [data] => 9
        [link] => 
    )

    [count:CircularLinkedList:private] => 4
 )

    CircularLinkedList Object
    (
      [first:CircularLinkedList:private] => Node Object
      (
        [data] => 2
        [link] => Node Object
            (
                [data] => 10
                [link] => Node Object
                    (
                        [data] => 3
                        [link] => Node Object
                            (
                                [data] => 9
                                [link] => Node Object
       *RECURSION*
                            )

                    )

            )

       )

    [current:CircularLinkedList:private] => Node Object
    (
        [data] => 9
        [link] => Node Object
            (
                [data] => 2
                [link] => Node Object
                    (
                        [data] => 10
                        [link] => Node Object
                            (
                                [data] => 3
                                [link] => Node Object
         *RECURSION*
                            )

                    )

            )

     )

    [count:CircularLinkedList:private] => 4
   )

对于通告-更改为：

     function push($data){

       if($this->isEmpty()){
         $this->first   = new Node($data);
         $this->current = $this->first;
         $this->count++;
       }
       else{

        $this->current->link = new Node($data, $this->first);
        $this->current = $this->current->link;
        $this->count++;

      }

    }

这种结构产生：

    CircularLinkedList Object
    (
      [first:CircularLinkedList:private] => Node Object
      (
        [data] => 2
        [link] => Node Object
            (
                [data] => 10
                [link] => Node Object
                    (
                        [data] => 3
                        [link] => Node Object
                            (
                                [data] => 9
                                [link] => 
                            )

                    )

            )

    )

    [current:CircularLinkedList:private] => Node Object
    (
        [data] => 9
        [link] => 
    )

    [count:CircularLinkedList:private] => 4
 )

    CircularLinkedList Object
    (
      [first:CircularLinkedList:private] => Node Object
      (
        [data] => 2
        [link] => Node Object
            (
                [data] => 10
                [link] => Node Object
                    (
                        [data] => 3
                        [link] => Node Object
                            (
                                [data] => 9
                                [link] => Node Object
       *RECURSION*
                            )

                    )

            )

       )

    [current:CircularLinkedList:private] => Node Object
    (
        [data] => 9
        [link] => Node Object
            (
                [data] => 2
                [link] => Node Object
                    (
                        [data] => 10
                        [link] => Node Object
                            (
                                [data] => 3
                                [link] => Node Object
         *RECURSION*
                            )

                    )

            )

     )

    [count:CircularLinkedList:private] => 4
   )

你可以用

$ll = new CircularLinkedList();

$ll->push(5);
$ll->push(6);
$ll->push(7);
$ll->push(8);
$ll->push(9);
$ll->push(10);
echo "<pre>";

类节点

class CircularLinkedList implements Countable {
    private $data;
    private $current;
    private $count;

    function __construct() {
        $this->count = 0;
        $this->data = null;
        $this->current = null;
    }

    function isEmpty() {
        return ($this->data == NULL);
    }

    function push($data) {
        $p = new Node($data);
        if ($this->isEmpty()) {
            $this->data = $p;
            $this->current = $this->data;
        } else {
            $this->current->link = $p ;
            $this->current = $this->current->link;
        }
        $this->count ++;
    }

    function find($value) {
        $q = $this->data;
        while ( $q->link != null ) {
            if ($q->data == $value)
                $this->current = $q;
            $q = $q->link;
        }
        return false;
    }

    function getCurrent() {
        return $this->current;
    }

    function getNext() {
        $this->current = $this->current->link;
    }

    function hasNext() {
        return isset($this->current->link);
    }

    function isValid() {
        return isset($this->current);
    }

    function reset() {
        $this->current = $this->data;
    }

    function count() {
        return $this->count;
    }
}

类循环链接列表

---

我的假设是你的链接是不正确的。因此，第38行是一个无限循环。一些调试可能会证明这一点。我知道问题出在第38行。但逻辑似乎是正确的。问题是如何调试您是否签出了

SplDoublyLinkedList

和朋友？你可能不需要自己做这一切。可以扩展一个SPL类@Kris：它不支持循环链表和我需要的一些功能，扩展该类并进行修改可能会再次产生类似的问题！我接受了乔·布朗的答案，因为它更接近我的实现。但是你的好答案也是+1！我只是觉得（$j=0；$jSorry，我忘了检查，这不是一个循环链接列表！它是线性的！Ali，第二个示例是循环的，因为最后一个节点链接指向第一个节点。因此结构告诉您它本身是递归的。嗨，如果我想在第一个位置插入一个新节点，您能告诉我push方法更改应该是什么吗

class CircularLinkedList implements Countable {
    private $data;
    private $current;
    private $count;

    function __construct() {
        $this->count = 0;
        $this->data = null;
        $this->current = null;
    }

    function isEmpty() {
        return ($this->data == NULL);
    }

    function push($data) {
        $p = new Node($data);
        if ($this->isEmpty()) {
            $this->data = $p;
            $this->current = $this->data;
        } else {
            $this->current->link = $p ;
            $this->current = $this->current->link;
        }
        $this->count ++;
    }

    function find($value) {
        $q = $this->data;
        while ( $q->link != null ) {
            if ($q->data == $value)
                $this->current = $q;
            $q = $q->link;
        }
        return false;
    }

    function getCurrent() {
        return $this->current;
    }

    function getNext() {
        $this->current = $this->current->link;
    }

    function hasNext() {
        return isset($this->current->link);
    }

    function isValid() {
        return isset($this->current);
    }

    function reset() {
        $this->current = $this->data;
    }

    function count() {
        return $this->count;
    }
}