/**
 * struct ListNode {
 *	int val;
 *	struct ListNode *next;
 * };
 */

/**
 * 
 * @param pListHead ListNode类 
 * @param k int整型 
 * @return ListNode类
 */
struct ListNode* FindKthToTail(struct ListNode* pListHead, int k ) {
    if(pListHead == NULL||k == 0)
    {
        return NULL;
    }
    struct ListNode* fast = pListHead;
    struct ListNode* slow = pListHead;
    //保持K个距离走
    int count= k-1;
    while(count--)
    {
        if(fast)
            fast = fast->next;
    }
    if(fast == NULL)
    {
        return NULL;
    }
    while(fast->next)
    {
        fast =fast->next;
        slow =slow->next;
    }
    return slow;
}