求链表中倒数第K个节点

1、求链表中倒数第K个节点

 

ListNode* FindKthToTail(ListNode* pListHead, unsigned int k)
{
        if(pListHead == NULL || k == 0)
                return NULL;

        ListNode *pAhead = pListHead;
        ListNode *pBehind = NULL;

        for(unsigned int i = 0; i < k - 1; ++ i)
        {
                pAhead = pAhead->m_pNext;
    if(pAhead == NULL)
      return NULL;
        }

        pBehind = pListHead;

        while(pAhead->m_pNext != NULL)
        {
                pAhead = pAhead->m_pNext;
                pBehind = pBehind->m_pNext;
        }

        return pBehind;
}