leetcode 面试题 02.02. 返回倒数第 k 个节点

我的解题

/* Program to implement a stack
 using two queue */
#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)
    {
    }
};

class Solution
{
public:
    int kthToLast(ListNode *head, int k)
    {
        ListNode *fast = head, *slow = head;
        while (k-- > 0)
        {
            fast = fast->next;
        }
        while (fast)
        {
            fast = fast->next;
            slow = slow->next;
        }
        return slow->val;
    }
};

// Driver code
int main()
{
    ListNode *N = new ListNode { 3 };
    N->next = new ListNode { 2 };
    N->next->next = new ListNode { 0 };
    N->next->next->next = new ListNode { 4 };
    Solution s;
    cout << s.kthToLast(N, 1) << endl;

    return 0;
}
// g++ test.cpp --std=c++11 -pedantic -Wall -Wextra