/*

struct ListNode {

    int val;

    struct ListNode *next;

    ListNode(int x) :

            val(x), next(NULL) {

    }

};*/

class Solution {

    public:

        ListNode* FindKthToTail(ListNode* pListHead, unsigned int k) {

            if(pListHead==NULL||k==) return NULL;

            int pos_pre = ;

            ListNode* node_pre = pListHead, *node_tail = pListHead;

            while(node_tail->next != NULL) {

                node_tail = node_tail->next;

                pos_pre++;

                if(pos_pre > k) {

                    node_pre = node_pre->next;

                }

            }

            if(pos_pre < k) return NULL;

            return node_pre;

        }

};