Method compare

src/com/blankj/medium/_0056/Solution.java:21–26

(Interval o1, Interval o2)

        if (intervals == null || intervals.size() <= 1) return intervals;
        intervals.sort(new Comparator<Interval>() {
            @Override
            public int compare(Interval o1, Interval o2) {
                if (o1.start < o2.start) return -1;
                if (o1.start > o2.start) return 1;
                return 0;
            }
        });
        List<Interval> ans = new ArrayList<>();
        int start = intervals.get(0).start;