题解 | #合并区间#

方法：模拟

1. 先对list进行排序
2. 从list中拿出第i个和第i+1个
3. 判断是否有重叠：(v1.start >= v2.start && v1.start <= v2.end) || (v2.start >= v1.start && v2.start <= v1.end)

    public ArrayList<Interval> merge(ArrayList<Interval> intervals) {
        Collections.sort(intervals, new Comparator<Interval>() {
            @Override
            public int compare(Interval o1, Interval o2) {
                if (o1.start != o2.start) {
                    return o1.start - o2.start;
                }else {
                    return o1.end - o2.end;
                }
            }
        });
        int i = 0;
        while (i < intervals.size() - 1) {
            Interval v1 = intervals.get(i);
            Interval v2 = intervals.get(i + 1);
            if ((v1.start >= v2.start && v1.start <= v2.end) || (v2.start >= v1.start && v2.start <= v1.end)) {
                Interval newV = new Interval(Math.min(v1.start, v2.start), Math.max(v1.end, v2.end));
                intervals.remove(i);
                intervals.remove(i);
                intervals.add(i, newV);
            }else {
                i++;
            }
        }
        return intervals;
    }
}