快慢指针问题

 1 Status GetMidNode(LinkList L, ElemType *e)
 2 {
 3     LinkList search, mid;
 4     mid = search = L;
 5 
 6     while (search->next != NULL)
 7     {
 8         //search移动的速度是 mid 的2倍
 9         if (search->next->next != NULL)
10         {
11             search = search->next->next;
12             mid = mid->next;
13         }
14         else
15         {
16             search = search->next;
17         }
18     }
19 
20     *e = mid->data;
21 
22     return OK;
23 }