【Leetcode 206】关关的刷题日记70 – Leetcode 206. Reverse Linked List

class Solution {public:
    ListNode* reverseList(ListNode* head) {
        ListNode* p, *q, *r;
        p=head;
        if(p==nullptr)
            return p;
        q=p->next;
        while(q!=nullptr)
        {
            r=q->next;
            q->next=p;
            p=q;
            q=r;
        }
        head->next=nullptr;
        head=p;
        return head;
    }};