本文實(shí)例講述了PHP實(shí)現(xiàn)單鏈表翻轉(zhuǎn)操作。分享給大家供大家參考,具體如下:
當(dāng)一個(gè)序列中只含有指向它的后繼結(jié)點(diǎn)的鏈接時(shí),就稱該鏈表為單鏈表。
這里給出了一個(gè)單鏈表的定義及翻轉(zhuǎn)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 = $next; }}//遍歷,將當(dāng)前節(jié)點(diǎn)的下一個(gè)節(jié)點(diǎn)緩存后更改當(dāng)前節(jié)點(diǎn)指針 function reverse($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(jié)點(diǎn)的下一個(gè)節(jié)點(diǎn)置為null,再將反轉(zhuǎn)后的頭節(jié)點(diǎn)賦給head $head->setNext(null); $head = $pre; return $head;}//遞歸,在反轉(zhuǎn)當(dāng)前節(jié)點(diǎn)之前先反轉(zhuǎn)后續(xù)節(jié)點(diǎn) function reverse2($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; $cur = null; // 構(gòu)造一個(gè)長度為10的鏈表,保存頭節(jié)點(diǎn)對象head for($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(yùn)行結(jié)果:
0 1 2 3 4 5 6 7 8 9 9 8 7 6 5 4 3 2 1 0
希望本文所述對大家PHP程序設(shè)計(jì)有所幫助。
新聞熱點(diǎn)
疑難解答
圖片精選