剑指offer ：从尾到头打印链表

/**
*  struct ListNode {
*        int val;
*        struct ListNode *next;
*        ListNode(int x) :
*              val(x), next(NULL) {
*        }
*  };
*/
class Solution {
public:
    vector<int> printListFromTailToHead(ListNode* head) {
        vector<int> res;
        stack<int> s;
        ListNode* cur = head;
        if(head == NULL)
            return res;
        while(cur != NULL)
        {
            s.push(cur->val);
            cur = cur->next;
        }
        while(!s.empty())
        {
            res.push_back(s.top());
            s.pop();
        }
        return res;
    }
};