分析
1、 遍历一遍链表即可
2、 unshift 从数组最前加入
Code
/**
* Definition for singly-linked list.
* function ListNode(val) {
* this.val = val;
* this.next = null;
* }
*/
/**
* @param {ListNode} head
* @return {Number[]}
*/
var printListReversingly = function(head) {
const ans = [];
while(head){
ans.unshift(head.val);
head = head.next;
}
return ans;
}