剑指offer面试题06 从尾到头打印链表C++

题目描述：输入一个链表的头节点，从尾到头反过来返回每个节点的值（用数组返回）。

反转法：

* Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:
    vector<int> reversePrint(ListNode* head) {
        vector<int>res;
        while(head){
            res.push_back(head->val);
            head=head->next;
        }
        reverse(res.begin(),res.end());
        return res;
    }
};

入栈法：

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