147. Insertion Sort List

    public static ListNode insertionSortList(ListNode head) {            if(head == null) {                return null;            }            ListNode cur = head.next,thead = head,tcur =head, tn =null;            thead.next = null;            while(cur != null) {                tn = cur.next;                if(cur.val > tcur.val) {                    cur.next =null;                    tcur.next = cur;                    tcur = cur;                }else {                    ListNode tmp = thead,pre = null;                    while(tmp.val < cur.val) {                        pre = tmp;                        tmp = tmp.next;                    }                    if(pre == null) {                        cur.next = thead;                        thead = cur;                    }else{                        cur.next = pre.next;                        pre.next = cur;                    }                }                cur =tn;            }            return thead;    }