206. 反转链表

C++

方法：

class Solution {
public:
    ListNode* reverseList(ListNode* head) {
        ListNode *prev = nullptr;
        while (head != nullptr)
        {
            ListNode *temp = head->next;
            head->next = prev;
            prev = head;
            head = temp;
        }
        return prev;
    }
};