JZ6 从尾到头打印链表

#include <algorithm>
#include <list>
#include <vector>
class Solution {
public:
    vector<int> printListFromTailToHead(ListNode* head) {
        if(!head)return {};
        ListNode* p = head;
        int len = 0;
        while (p!=nullptr) {
            p = p->next;
            len++;        
        }
        vector<int> res(len);
        for(int i = len -  1;i>=0;--i){
            res[i] = head->val;
            head = head->next;
        }
        return res;    
    }
};