剑指offer——26反转链表

 1 class Solution {
 2 public:
 3     ListNode* ReverseList(ListNode* pHead) {
 4         if (pHead == nullptr || pHead->next == nullptr)return pHead;
 5         ListNode  *pre = nullptr, *cur = nullptr, *next = nullptr;
 6         cur = pHead;
 7         while (cur != nullptr)
 8         {
 9             next = cur->next;
10             cur->next = pre;
11             pre = cur;
12             cur = next;
13         }
14         return pre;
15     }
16 };