剑指OFFER-合并两个排序的链表-PHP

题目

题解

代码

<?php
/*class ListNode{
var $val;
var $next = NULL;
function __construct($x){
$this->val = $x;
}
}*/
function Merge($pHead1, $pHead2)
{
if($pHead1 == NULL)
return $pHead2;
if($pHead2 == NULL)
return $pHead1;
$reHead = new ListNode();

if($pHead1->val < $pHead2->val){
$reHead = $pHead1;
$pHead1 = $pHead1->next;
}else{
$reHead = $pHead2;
$pHead2 = $pHead2->next;
}

$p = $reHead;
while($pHead1&&$pHead2){
if($pHead1->val <= $pHead2->val){
$p->next = $pHead1;
$pHead1 = $pHead1->next;
$p = $p->next;
}
else{
$p->next = $pHead2;
$pHead2 = $pHead2->next;
$p = $p->next;
}
}
if($pHead1 != NULL){
$p->next = $pHead1;
}
if($pHead2 != NULL)
$p->next = $pHead2;

return $reHead;
}