/*

 题目:输入一个单向链表,输出该链表中倒数第 k 个结点。链表的倒数第 0 个结点为链表

 的尾指针。

 链表结点定义如下:

 struct node

 {

     int data;

     struct node *next;

 };

 typedef struct node* PtrToNode;

 typedef PtrToNode Position;

 typedef Position List;

 */

 #include <iostream>

 #include <assert.h>

 #include "./List.h"

 using namespace std;

 void print_list(List list)

 {

     assert(list != NULL);

     list = First(list);

     while(list != NULL)

     {

         cout<<list->data<<" ";

         list = list->next;

     }

     cout<<endl;

 }

 Position get_last_kth(List list, int k)

 {

     assert(list != NULL);

     Position tmp = First(list);

     while(tmp != NULL && --k >= )

         tmp = tmp->next;

     if(NULL == tmp)//the length of list <= k

         return NULL;

     Position ret = First(list);

     while(tmp != NULL)

     {

         ret = ret->next;

         tmp = tmp->next;

     }

     return ret;

 }

 int main(int argc, char const *argv[])

 {

     List list = CreateEmptyList();

     int k;

     for(int i = ; i != ; ++i)

         PushBack(i, list);

     print_list(list);

     while(cin>>k)

     {

         Position tmp = get_last_kth(list, k);

         cout<<"k:"<<k<<" = ";

         if(tmp == NULL)

             cout<<"NULL";

         else

             cout<<tmp->data;

         cout<<endl;

     }

     return ;

 }