剑指offer

 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 *tmp = pListHead, *res = pListHead;
13         /* unsigned int cnt = 0;
14         for (; tmp != NULL; cnt++) {
15             if (cnt >= k)
16                 res = res->next;
17             tmp = tmp->next;
18         }
19         return cnt < k ? NULL : res; */
20         int cnt = 0;
21         while (tmp != NULL && (cnt < k)) {
22             tmp = tmp->next;
23             cnt++;
24         }
25         while (tmp != NULL) {
26             tmp = tmp->next;
27             res = res->next;
28         }
29         return cnt < k ? NULL : res;
30     }
31 };