<?php
class ListNode
{
    public $val;
    public $nxt;
    function __construct($val)
    {
        $this->val = $val;
        $this->nxt = NULL;
    }
 
    function readNode()
    {
        return $this->val;
    }
}
 
class ReverseLinkedList
{
    private $first;
    private $last;
    private $count;
 
    function __construct()
    {
        $this->first = NULL;
        $this->last = NULL;
        $this->count = 0;
    }
 
    //insert First Node
    public function insertFirst($val)
    {
        $link = new ListNode($val);
        $link->nxt = $this->first;
        $this->first = &$link;
 
        if($this->last == NULL)
            $this->last = &$link;
            $this->count++;
    }
 
    public function show()
    {
        $listval = array();
        $cur = $this->first;
        while($cur != NULL)
        {
            array_push($listval, $cur->readNode());
            $cur = $cur->nxt;
        }
        foreach($listval as $v){
            echo $v." ";
        }
    }
 
    public function reverseLinkedList()
    {
        if($this->first != NULL)
        {
            if($this->first->nxt != NULL)
            {
                $cur = $this->first;
                $new = NULL;
 
                while ($cur != NULL)
                {
                    $temp = $cur->nxt;
                    $cur->nxt = $new;
                    $new = $cur;
                    $cur = $temp;
                }
                $this->first = $new;
            }
        }
    }
 
 
    //insertion at ith key
    public function insert($NewItem,$key)
    {
        if($key == 0){
        $this->insertFirst($NewItem);
    }
    else
    {
        $link = new ListNode($NewItem);
        $cur = $this->first;
        $previous = $this->first;
 
        for($i=0;$i<$key;$i++)
        {       
                $previous = $cur;
                $cur = $cur->nxt;
        }
 
           $previous->nxt = $link;
           $link->nxt = $cur; 
           $this->count++;
    }
 
    }   
}
 
$o = new ReverseLinkedList();
//$o->insertFirst($value);
//$o->insert($value,$key); // at any index
 
$o->insertFirst(1);
$o->insert(2,1);
$o->insert(3,2);
$o->insert(4,3);
$o->insert(5,4);
$o->reverseLinkedList();
$o->show();

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