题解 | #合并区间#

O(val)的时间怎么搞呢

import java.util.*;
import java.util.stream.Collectors;
/**
 * Definition for an interval.
 * public class Interval {
 *     int start;
 *     int end;
 *     Interval() { start = 0; end = 0; }
 *     Interval(int s, int e) { start = s; end = e; }
 * }
 */
public class Solution {
    public ArrayList<Interval> merge(ArrayList<Interval> intervals) {
        if (intervals.size() < 2) {
            return intervals;
        }
        intervals.sort(Comparator.comparingInt(o -> o.start));
        int count = 0;
        ArrayList<Interval> list = new ArrayList<>();
        list.add(intervals.remove(count));
        for (Interval current : intervals) {
            Interval last = list.get(count);
            if (last.end < current.start) {
                list.add(current);
                count++;
            } else {
                // 区间有重叠
                list.remove(count);
                list.add(new Interval(last.start, Math.max(last.end, current.end)));
            }
        }
        return list;
    }
}