LeetCode 92. 反转链表 II

class Solution {
public:
    ListNode* reverseBetween(ListNode* head, int m, int n) {
        auto dummy=new ListNode(-1);
        dummy->next=head;
        auto a=dummy;
        for(int i=0;inext;
        auto b=a->next,c=a->next->next;
        for(int i=0;inext;
            c->next=b;
            b=c;c=t;
        }
        a->next->next=c;
        a->next=b;
        return dummy->next;

    }
};