单链表反转

void reverse(List* list)
{
    Node* before = list->first;  
    if (before != NULL)
    {
        Node* after = before->next;  
        before->next = NULL;  
        while (after)  
        {  
            //交换指针  
            Node* temp = after->next;  
            after->next = before;  
            before = after;  
            after = temp;  
        }  
    }
}