链表倒数第k个节点

 1 /*
 2 struct ListNode {
 3     int val;
 4     struct ListNode *next;
 5     ListNode(int x) :
 6             val(x), next(NULL) {
 7     }
 8 };*/
 9 class Solution {
10 public:
11     ListNode* FindKthToTail(ListNode* pListHead, unsigned int k) {
12         //边界判断！！！
13         if(pListHead == nullptr || k == 0)
14             return nullptr;
15         auto p = pListHead;
16         //快先走k-1
17         for(int i=0; i<k-1; i++)
18         {
19             if(p->next == nullptr)
20                 return nullptr;
21             else
22                 p = p->next;
23         }
24         //一起走到尾
25         while(p->next != nullptr)
26         {
27             p = p->next;
28             pListHead = pListHead->next;
29         }
30         return pListHead;
31     }
32 };