Day 15: Linked List

https://www.hackerrank.com/challenges/30-linked-list/problem

<?php
class Node{
    public $data;
    public $next;
    function __construct($d)
    {
        $this->data = $d;
        $this->next = NULL;
    }
}
class Solution{
    function insert($head,$data){
        $node = new Node($data);
        
        if($head == null) {
            $head = $node;
        } else if ($head->next == null) {
            $head->next = $node;
        } else {
            $start = $head;
            while($start->next != null) {
                $start = $start->next;
            }
            $start->next = $node;
        }
        return $head;
    }

function display($head){
    $start=$head;
        while($start){
            echo $start->data,' ';
            $start=$start->next;
        }
    }
}
$T=intval(fgets(STDIN));
$head=null;
$mylist=new Solution();
while($T-->0){
    $data=intval(fgets(STDIN));
    $head=$mylist->insert($head,$data);
}
$mylist->display($head);
?>