题解 | #链表内指定区间反转#

 * struct ListNode {
 *	int val;
 *	struct ListNode *next;
 * };
 */

class Solution {
public:
    /**
     * 
     * @param head ListNode类 
     * @param m int整型 
     * @param n int整型 
     * @return ListNode类
     */
    ListNode* successor;
    ListNode* reverseN(ListNode* head, int n){
        if(n == 1){
            successor = head->next;
            return head;
        }
        ListNode* last = reverseN(head->next, n - 1);
        head->next->next = head;
        head->next = successor;
        return last;
    }
    ListNode* reverseBetween(ListNode* head, int m, int n) {
        // write code here
        if(m == 1){
            return reverseN(head, n);
        }
        head->next = reverseBetween(head->next, m-1, n-1);
        return head;
    }
};