翻转链表

class Solution {public:    ListNode* ReverseList(ListNode* pHead) {                if(pHead == NULL) return NULL;                ListNode* newHead = pHead;        pHead = pHead->next;        newHead->next = NULL;                while(pHead != NULL){            ListNode* temp = pHead;            pHead = pHead->next;            temp->next = newHead;            newHead = temp;        }                return newHead;    }        };