Sorting

3가지 방법

Comparable

class Interval implements Comparable<Interval>{
    int start;
    int end;
    Interval(int start,int end){
        this.start=start;
        this.end=end;
    }


    @Override
    public int compareTo(Interval o) {
        return this.start-o.start;
    }
}

Comparator

Comparator<Interval> comparator = new Comparator<Interval>() {
    @Override
    public int compare(Interval o1, Interval o2) {
        return o1.start - o2.start;
    }
};

lambda

Collections.sort(intervalList, (a, b) -> b.start - a.start);