PHP實現單鏈表翻轉操作示例

2024-05-05 00:01:20

字體：大中小

來源：轉載

供稿：網友

本文實例講述了PHP實現單鏈表翻轉操作。分享給大家供大家參考，具體如下：

當一個序列中只含有指向它的后繼結點的鏈接時，就稱該鏈表為單鏈表。

這里給出了一個單鏈表的定義及翻轉操作方法：

<?php/** * @file reverseLink.php * @author showersun * @date 2016/03/01 10:33:25 **/class Node{  private $value;  private $next;  public function __construct($value=null){    $this->value = $value;  }  public function getValue(){    return $this->value;  }  public function setValue($value){    $this->value = $value;  }  public function getNext(){    return $this->next;  }  public function setNext($next){    $this->next = $next;  }}//遍歷，將當前節點的下一個節點緩存后更改當前節點指針 function reverse($head){  if($head == null){    return $head;  }  $pre = $head;//注意：對象的賦值  $cur = $head->getNext();  $next = null;  while($cur != null){    $next = $cur->getNext();    $cur->setNext($pre);    $pre = $cur;    $cur = $next;  }  //將原鏈表的頭節點的下一個節點置為null，再將反轉后的頭節點賦給head   $head->setNext(null);  $head = $pre;  return $head;}//遞歸，在反轉當前節點之前先反轉后續節點 function reverse2($head){  if (null == $head || null == $head->getNext()) {    return $head;  }  $reversedHead = reverse2($head->getNext());  $head->getNext()->setNext($head);  $head->setNext(null);  return $reversedHead;}function test(){  $head = new Node(0);  $tmp = null;  $cur = null;  // 構造一個長度為10的鏈表，保存頭節點對象head    for($i=1;$i<10;$i++){    $tmp = new Node($i);    if($i == 1){      $head->setNext($tmp);    }else{      $cur->setNext($tmp);    }    $cur = $tmp;  }  //print_r($head);exit;  $tmpHead = $head;  while($tmpHead != null){    echo $tmpHead->getValue().' ';    $tmpHead = $tmpHead->getNext();  }  echo "/n";  //$head = reverse($head);  $head = reverse2($head);  while($head != null){    echo $head->getValue().' ';    $head = $head->getNext();  }}test();?>

運行結果：