leetcode 剑指 Offer 06. 从尾到头打印链表

我的解题

使用后序遍历、implicit stack

#include <bits/stdc++.h>
using namespace std;

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
struct ListNode
{
    int val;
    ListNode *next;
    ListNode(int x) :
                    val(x), next(NULL)
    {
    }
};

class Solution
{
public:
    vector<int> reversePrint(ListNode *head)
    {
        vector<int> res;
        reversePrintRecursion(head, res);
        return res;
    }
    void reversePrintRecursion(ListNode *head, vector<int> &res)
    {
        if (head)
        {
            reversePrintRecursion(head->next, res);
            res.push_back(head->val);
        }
        else
        {
            return;
        }
    }
};

int main()
{

}
// g++ test.cpp --std=c++11 -pedantic -Wall -Wextra

reverse by stack用栈来进行反转、explicit stack

#include <bits/stdc++.h>
using namespace std;

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
struct ListNode
{
    int val;
    ListNode *next;
    ListNode(int x) :
                    val(x), next(NULL)
    {
    }
};

class Solution
{
public:
    vector<int> reversePrint(ListNode *head)
    {
        stack<ListNode*> st;
        while (head)
        {
            st.push(head);
            head = head->next;
        }
        vector<int> res;
        while (!st.empty())
        {
            res.push_back(st.top()->val);
            st.pop();
        }
        return res;
    }
};

int main()
{

}
// g++ test.cpp --std=c++11 -pedantic -Wall -Wextra