struct ListNode

 {

     int m_nValue;

     ListNode* m_pNext;

 };

 ListNode* FindKthToTail(ListNode* pListHead , unsigned int K)

 {

     if (!pListHead || K <=)

     {

         return NULL ;

     }

     ListNode* pAhead = pListHead;

     ListNode* pBehind = NULL ;

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

     {

         if (pAhead->m_pNext != NULL)

         {

             pAhead = pAhead->m_pNext ;

         }

         else

         {

             return NULL;

         }

     }

     pBehind = pListHead ;

     while(pAhead->m_pNext != NULL)

     {

         pAhead = pAhead->m_pNext ;

         pBehind = pBehind->m_pNext;

     }

     return pBehind ;

 }