反转链表

反转链表

ListNode* ReverseList(ListNode* pHead) {
if(pHead==NULL)
return NULL;
ListNode* pReservedHead = pHead;
ListNode* pNode = pHead;
ListNode* pPrev = NULL;
ListNode* tmp = NULL;
while(pNode!=NULL){
if(pNode->next==NULL)
//return pNode; //不可以直接返回，因为还未设定pNode的next节点
 pReservedHead = pNode;  
/*if(pNode->next==NULL){
        pNode->next = pPrev;
        return pNode;
       }
*/

 tmp=pNode->next;
pNode->next = pPrev;
pPrev = pNode;
pNode = tmp;
}
return pReservedHead;
}