LeeCode 單鏈表逆序

題目：Reverse a singly linked list

C代碼：

/**
 * 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;
    
}