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 ) {
    if(pListHead==NULL){
        return NULL;
    }
    struct ListNode* slow,*fast;
    fast=pListHead;
    slow=pListHead;
    while (k) {
    fast=fast->next;
    if(fast==NULL&&k!=1)//如果k！=1，就说明k超出了链表的长度
	{
        return NULL;
    }
    k--;
    }
    while(fast){
        fast=fast->next;
        slow=slow->next;

    }
    return slow;
}