57 Insert Interval

public class Solution {
    public List<Interval> insert(List<Interval> intervals, Interval newInterval) {
        List<Interval> res = new ArrayList<Interval>();
        if (intervals == null || intervals.isEmpty()) {
            res.add(newInterval);
            return res;
        }
        if (newInterval == null) {
            return intervals;
        }
        
        int insertPos = 0;
        for (Interval interval : intervals) {
            if (interval.end  < newInterval.start) {
                res.add(interval);
                insertPos++;
            } else if (interval.start > newInterval.end) {
                res.add(interval);
            } else {
                newInterval.start = Math.min(interval.start, newInterval.start);
                newInterval.end = Math.max(interval.end, newInterval.end);
            }
        }
        res.add(insertPos, newInterval);
        return res;
        
    }
}

参考九章答案