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* reverseBetween(ListNode* head, int m, int n) {
        // write code here
        ListNode* dummy = new ListNode(0);
        dummy->next = head; //防止m=1
        ListNode *pre = dummy;
        ListNode *cur;
        for(int i =1;i<m;i++){
            pre = pre->next;//找到头
        }
        cur = pre->next;
        for(int i =0;i<n-m;i++){
            ListNode *cur_next = cur->next;
            cur->next = cur->next->next;
            cur_next->next = pre->next;
            pre->next = cur_next;
        }
        return dummy->next;
    }
};