题解 | #从尾到头打印链表# 反转后从头到尾打印

/**
*  struct ListNode {
*        int val;
*        struct ListNode *next;
*        ListNode(int x) :
*              val(x), next(NULL) {
*        }
*  };
*/
class Solution {
public:
    vector<int> printListFromTailToHead(ListNode* head) {
        ListNode* rhead = reverseList(head);
        vector<int> ans;
        while (rhead) {
            ans.push_back(rhead->val);
            rhead = rhead->next;
        }
        return ans;
    }

    ListNode* reverseList(ListNode* head) {
        ListNode *cur = head, *pre = nullptr;
        while (cur) {
            ListNode* nex = cur->next;
            cur->next = pre;
            pre = cur;
            cur = nex;
        }
        return pre;
    }
};