LeetCode57 插入区间

设置新插入的区间为pre，当pre和cur没交集且pre在前面(pre.end

public List insert(List intervals, Interval newInterval) {
        List list = new LinkedList<>();
        Interval pre = newInterval;
        for(Interval curr: intervals){
            if(pre.end < curr.start) {
                list.add(pre);
                pre = curr;
            } else if (curr.end < pre.start) {   //Here is the difference.
                list.add(curr);
            }
            else {
                pre.start = Math.min(pre.start, curr.start);
                pre.end = Math.max(pre.end, curr.end);
            }
        }
        list.add(pre);
        return list;
    }