剑指offer--3.从头打印链表

题目：输入一个链表，按链表值从尾到头的顺序返回一个ArrayList。

思路：可以利用push 和unshift

/*function ListNode(x){
    this.val = x;
    this.next = null;
}*/
function printListFromTailToHead(head)
{
    var res = [];
    while(head) {
        res.push(head.val);
        head = head.next;
    }
    return res.reverse();
}

/*function ListNode(x){
    this.val = x;
    this.next = null;
}*/
function printListFromTailToHead(head)
{
    var res = [];
    while(head) {
        res.unshift(head.val);
        head = head.next;
    }
    return res;
}