Insert Interval

Given a set of non-overlapping intervals, insert a new interval into the intervals (merge if necessary).

You may assume that the intervals were initially sorted according to their start times.

public class Solution {
    public ArrayList<Interval> insert(ArrayList<Interval> intervals, Interval newInterval) {
        ArrayList<Interval> res = new ArrayList<Interval>();
        if(intervals.size()==0){
            res.add(newInterval);
            return res;
        }
        for(int i=0;i<intervals.size();i++){
            Interval cur = intervals.get(i);
            if(newInterval.end<cur.start){
                res.add(newInterval);
                for(int j=i;j<intervals.size();j++){
                    res.add(intervals.get(j));
                }
                return res;
            }
            else if(cur.end<newInterval.start){
                res.add(cur);
            }
            else{
                int left = Math.min(newInterval.start,cur.start);
                int right = Math.max(newInterval.end,cur.end);
                newInterval.start = left;
                newInterval.end =right;
            }
        }
        res.add(newInterval);
        return res;   
    }
}