题解 | #链表中倒数第k个结点#

/**
 * 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)
{
    struct ListNode* fast = pListHead, * slow = pListHead;
    int tmp = k - 1;
    while (fast && fast->next)
    {
        while (tmp)
        {
            fast = fast->next;
            if (fast == NULL)
            {
                break;
            }
            tmp--;
        }
        if(tmp == 0)
        {
            if (fast->next)
            {
                slow = slow->next;
                fast = fast->next;
            }
        }
        else
        {
            break;
        }
    }
    if (tmp == 0)
    {
        return slow;
    }
    else
    {
        return NULL;
    }
}