LeeCode 单链表逆序

题目：Reverse a singly linked list

C代码：

/** * Definition for singly-linked list. * struct ListNode { *     int val; *     struct ListNode *next; * }; */struct ListNode* reverseList(struct ListNode* head) {    if(NULL==head||NULL==head->next) return head;    struct ListNode *p=head->next;    head->next=NULL;    struct ListNode *newhead=reverseList(p);    p->next=head;    return newhead;    }