刷题6 从尾到头打印链表

 1 /**
 2 *  struct ListNode {
 3 *        int val;
 4 *        struct ListNode *next;
 5 *        ListNode(int x) :
 6 *              val(x), next(NULL) {
 7 *        }
 8 *  };
 9 */
10 class Solution {
11 public:
12     vector<int> printListFromTailToHead(ListNode* head) {
13         vector<int> array;
14 
15         while(head != NULL) 
16         {
17             array.push_back(head->val);
18             head = head->next;
19         }
20         
21         return vector<int>(array.rbegin(), array.rend());
22     }
23 };

 1 /**
 2 *  struct ListNode {
 3 *        int val;
 4 *        struct ListNode *next;
 5 *        ListNode(int x) :
 6 *              val(x), next(NULL) {
 7 *        }
 8 *  };
 9 */
10 class Solution {
11 public:
12     vector<int> printListFromTailToHead(ListNode* head) {
13         vector<int> result;
14         stack<int> stack;
15         while(head != NULL) 
16         {
17             stack.push(head->val);
18             head = head->next;
19         }
20         
21         while(!stack.empty())
22         {
23             result.push_back(stack.top());
24             stack.pop();
25         }
26         return result;
27     }
28 };