php 数据结构之链表队列

245 阅读 0 评论 162 点赞

我是靠谱客的博主热情小蚂蚁，这篇文章主要介绍php 数据结构之链表队列，现在分享给大家，希望可以做个参考。

php 链表队列

实例代码：

复制代码

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
class Queue{ 
  
  private $last; 
  private $first; 
  private $oldfirst; 
  private static $n=0; 
   
  public function __construct(){ 
    $this->last   = null; 
    $this->first  = null; 
    $this->oldfirst = null; 
  } 
   
  public function push($item){ 
    $this->oldfirst = $this->last; 
    $this->last = new Node(); 
    $this->last->item = $item; 
    $this->last->next = null; 
    if(empty($this->first)){ 
      $this->first = $this->last; 
    }else{ 
      $this->oldfirst->next = $this->last; 
    } 
    self::$n++; 
  } 
   
  public function pop(){ 
    if(self::$n<0){ 
      return null; 
    } 
    $item = $this->first->item; 
    $this->first = $this->first->next; 
    self::$n--; 
    return $item; 
  } 
   
} 
 
class Node{ 
  public $item; 
  public $next; 
} 
 
$Queue = new Queue(); 
$Queue->push("a"); 
$Queue->push("b"); 
$Queue->push("c"); 
echo $Queue->pop().PHP_EOL; 
echo $Queue->pop().PHP_EOL; 
echo $Queue->pop().PHP_EOL; 
echo $Queue->pop().PHP_EOL;