题解 | #链表中倒数第k个结点#

双指针。一个先走k-1步，然后大家再一起走

class Solution {
public:
    ListNode* FindKthToTail(ListNode* pHead, int k) {
        if(!pHead) return NULL;
        ListNode* ans=pHead;
        while(pHead->next&&k!=1){
            k--;
            pHead=pHead->next;
        }
        if(k!=1) return NULL;
        while(pHead->next){
            pHead=pHead->next;
            ans=ans->next;
        }
        return ans;
    }
};