如何保證一個鏈表(List)元素的有序性

在鏈表插入元素時保證鏈表的有序性.通過二分法來定位待插入元素的位置

  public void addNum(int num) {
        if(list.size()==0){
            list.add(num);
            return;
        }
       int l = 0;
	        int r = list.size()-1;
	        while(l<r){
	            int mid = l+(r-l)/2;
	            if(list.get(mid)>num)r=mid-1;
	            else l = mid +1;
	        }
            if(r>=0&&list.get(r)<num){
	        	list.add(r+1,num);
	        	return;
	        }
	        if(r>=0&&l<=list.size()-1&&num<list.get(r)&&num>list.get(l)){
		        list.add(l+1,num);
		        return;
	        }
	        list.add(l,num);
    }