leetcode题解:单链表就地倒置

class Solution
{
public:
    ListNode *reverseList(ListNode *head)
    {
        ListNode*H=(ListNode*)new ListNode(0);
        H->next=NULL;
        ListNode *p =head;
        if (p)
        {
            while (p)
            {
                ListNode *sub = p->next;
                p->next = H->next;
                H->next = p;
                p = sub;   
            }
            return(H->next);
        }
        else
            return (head);
    }
};