题解 | #链表中倒数最后k个结点#

/**
 * struct ListNode {
 *	int val;
 *	struct ListNode *next;
 *	ListNode(int x) : val(x), next(nullptr) {}
 * };
 */
class Solution {
public:
    ListNode* FindKthToTail(ListNode* pHead, int k) {
        int count=0;
        ListNode* p=pHead;
        while(p!=nullptr)
        {
            count++;
            p=p->next;
        }
        if(count<k)
            return nullptr;
        ListNode* low=pHead;
        ListNode* fast=pHead;
        for(int i=0;i<k;++i)
        {
            fast=fast->next;
        }
        while(fast!=nullptr)
        {
            fast=fast->next;
            low=low->next;
        }
        return low;
    }
};