/** * Definition for singly-linked list. * public class ListNode { *     int val; *     ListNode next; *     ListNode(int x) { val = x; } * } */public class Solution {    public ListNode insertionSortList(ListNode head) {                if(head==null || head.next==null) return head;            ListNode newHead=new ListNode(0);//后面使用tmp.next与pre比较，所以增加一个新的newHead                ListNode cur=head;                while(cur!=null){            ListNode next=cur.next;//放这里而不放在循环末尾，防止out of index            ListNode tmp=newHead;            while(tmp.next!=null && tmp.next.val<cur.val){                tmp=tmp.next;            }            cur.next=tmp.next;            tmp.next=cur;            cur=next;          }       return newHead.next;    }}