<?php

function getMsectime() {
    list($msec, $sec) = explode(' ', microtime());
    return (float)sprintf('%.0f', (floatval($msec) + floatval($sec)) * 1000);
}

class ListNode {
    public $val = 0;
    public $next = null;
    function __construct($val = 0, $next = null) {
        $this->val = $val;
        $this->next = $next;
    }
}
echo "<pre>";
class Solution {
    /**
     * 203.除链表元素
     * 
     * 给你一个链表的头节点 head 和一个整数 val ，请你删除链表中所有满足 Node.val == val 的节点，并返回 新的头节点 
     * 输入：head = [1,2,6,3,4,5,6], val = 6
     * 输出：[1,2,3,4,5]
     * 
     * @param ListNode $head
     * @param Integer $val
     * @return ListNode
     */
    function removeElements($head, $val) {
        $listNode = new ListNode(0, $head);
        $currNode = $listNode;
        while($currNode->next) {
            if ($currNode->next->val === $val) {
                $currNode->next = $currNode->next->next;
            } else {
                $currNode = $currNode->next;
            }
        }
        return $listNode->next;
    }
}

$solution = new Solution;
$head = [1,2,6,3,4,5,6];
$val = 6;

var_dump($solution->removeElements($head, $val));