[算法]向有序的环形单链表中插入新节点

public static Node insertNum(Node head,int num){
        Node node=new Node(num);
        if (head==null) {
            node.next=node;
            return node;
        }
        Node pre=head;
        Node cur=head.next;
        while(cur!=head){
            if (pre.value<=num&&cur.value>=num) {
                break;
            }else{
                pre=cur;
                cur=cur.next;
            }
        }
        pre.next=node;
        node.next=cur;
        return head.value<=num?head:node;
            }