【剑指Offer】（链表）从尾到头打印链表

r囧r小猫 2022-03-17 14:20 157阅读 0赞

**题目链接**：[https://www.nowcoder.com/practice/d0267f7f55b3412ba93bd35cfa8e8035?tpId=13&tqId=11156&tPage=1&rp=1&ru=/ta/coding-interviews&qru=/ta/coding-interviews/question-ranking][https_www.nowcoder.com_practice_d0267f7f55b3412ba93bd35cfa8e8035_tpId_13_tqId_11156_tPage_1_rp_1_ru_ta_coding-interviews_qru_ta_coding-interviews_question-ranking]

#### 题目描述 ####

输入一个链表，按链表值从尾到头的顺序返回一个ArrayList。

#### 解决方法 ####

/** * 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;
            if (!head) return res;
            if (!head->next) { res.push_back(head->val); return res;}
            //方法1：反转链表
            /*ListNode *new_head=nullptr; ListNode *temp=nullptr; while(head){ temp=head->next; head->next=new_head; new_head=head; head=temp; } //保存节点数据 while(new_head){ res.push_back(new_head->val); new_head=new_head->next; }*/
            //方法2：用栈
            stack<int> p;
            while(head){ 
                p.push(head->val);
                head=head->next;
            }
            while(!p.empty()){ 
                res.push_back(p.top());
                p.pop();
            }
            return res;
        }
    };

[https_www.nowcoder.com_practice_d0267f7f55b3412ba93bd35cfa8e8035_tpId_13_tqId_11156_tPage_1_rp_1_ru_ta_coding-interviews_qru_ta_coding-interviews_question-ranking]: https://www.nowcoder.com/practice/d0267f7f55b3412ba93bd35cfa8e8035?tpId=13&tqId=11156&tPage=1&rp=1&ru=/ta/coding-interviews&qru=/ta/coding-interviews/question-ranking