找到链表的倒数第K位

#include<iostream>
using namespace std;
 
class node{
public:
    node():value(),next(NULL){}
    ~node(){}
    int value;
    node* next;
};///be careful this ;
 
node* createlist(int a[],int n)
{
 node* startnode = new node[n];
 node* ret = startnode;
 for(int i = ;i<n;i++)
 {
     startnode[i].value = a[i];
     if(i<n-)
         startnode[i].next = startnode + i + ;
 }
 while(startnode)
 {
     cout<<" "<<startnode->value;
     startnode = startnode->next;
 }
 cout<<endl;
 return ret;
}
 
int helper(node* nd,int k)
{
 node* cursor1 = nd;
 node* cursor2 = nd;
 while(--k)
     cursor2 = cursor2->next;
 
 while(cursor2->next)
 {
     cursor1 = cursor1->next;
     cursor2 = cursor2->next;
 }
 
 return cursor1->value;
 
}
 
int main()
{
    int a[] = {,,,,,,,,};
    node * t = createlist(a,);
    cout<<helper(t,);
}