剑指offer 链表中倒数第k个结点

 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         ListNode* p = pListHead;
13         ListNode* q = pListHead;
14         unsigned int i = 0;
15         for( ;p != NULL; i ++){
16             if( i >= k)
17                 q = q->next;
18             p = p->next;
19         }
20         return i < k ? NULL : q;
21     }
22 };