#### C 代码
struct ListNode* findKthToTail(struct ListNode* pListHead, int k) {
    struct ListNode* cur1 = pListHead;
    struct ListNode* cur2 = pListHead;
    while(cur1)
    {
       k--;
       cur1 = cur1->next;
       if(k<0)
       {
          cur2 = cur2->next; 
       }
    }
    if(k<=0)
        return cur2;
    else 
        return NULL;
}