# Heading
Tags: algorithms linked-list
Langs: c cpp csharp golang java javascript kotlin php python python3 ruby rust scala swift typescript
- algorithms
- Medium (51.60%)
- Likes: 572
- Dislikes: -
- Total Accepted: 83.6K
- Total Submissions: 161.8K
- Testcase Example: '[1,2,3,4,5]\n2\n4'
反转从位置 m 到 n 的链表。请使用一趟扫描完成反转。
说明:
1 ≤ m ≤ n ≤ 链表长度。
示例:
输入: 1->2->3->4->5->NULL, m = 2, n = 4 输出: 1->4->3->2->5->NULL
/*
* @lc app=leetcode.cn id=92 lang=javascript
*
* [92] 反转链表 II
*/
// @lc code=start
/**
* Definition for singly-linked list.
* function ListNode(val) {
* this.val = val;
* this.next = null;
* }
*/
/**
* @param {ListNode} head
* @param {number} m
* @param {number} n
* @return {ListNode}
*/
var reverseBetween = function (head, m, n) {
let dummy = new ListNode(0, head);
let p = dummy
n -= m
while (p && m-- > 1) {
p = p.next
}
let ppre = p //插入点
p = p.next
let r = p.next
while (p && n-- > 0) {
p.next = r.next
r.next = ppre.next
ppre.next = r
r = p.next
}
return dummy.next
};
// @lc code=end
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40