import java.util.*;
public class Solution {
public ArrayList<Interval> merge(ArrayList<Interval> intervals) {
ArrayList<Interval> result = new ArrayList<>();
if(intervals==null || intervals.size()==0){
return result;
}
intervals.sort(Comparator.comparingInt(c -> c.start));
result.add(intervals.get(0));
for (int i = 1; i < intervals.size(); i++) {
Interval cur = result.get(result.size()-1);
if(cur.end<intervals.get(i).start){
result.add(intervals.get(i));
}else{
cur.end = Math.max(cur.end,intervals.get(i).end);
}
}
return result;
}
}