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
import { ListNode as Node } from "../reverse-linked-list/ListNode.ts";
export default function insert(    head: Node | null,    insertVal: number,): Node | null {    if (!head) {        const node = new Node(insertVal);        node.next = node;        return node;    }    const node = new Node(insertVal);
    let cur = head;    while (cur.next !== head) {        const nextval = cur.next?.val;        if (typeof nextval == "undefined") {            throw Error("none next node");        }        if (cur.val <= insertVal && nextval >= insertVal) {            break;        }        if (cur.val > nextval) {            if (nextval >= insertVal) {                break;            } else if (cur.val <= insertVal) {                break;            }        }        if (cur.next) {            cur = cur.next;        } else {            throw Error("none next node");        }    }    node.next = cur.next;    cur.next = node;    return head;}