题解 | #链表内指定区间反转#
链表内指定区间反转
https://www.nowcoder.com/practice/b58434e200a648c589ca2063f1faf58c
/**
* 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;
}
};
