LeetCode 1288. Remove Covered Intervals

Question

Given an array intervals where intervals[i] = [li, ri] represent the interval [li, ri), remove all intervals that are covered by another interval in the list.

The interval [a, b) is covered by the interval [c, d) if and only if c <= a and b <= d.

Return the number of remaining intervals.

https://leetcode.com/problems/remove-covered-intervals/

• Solution1

class Solution {
    public int removeCoveredIntervals(int[][] intervals) {
        Arrays.sort(intervals, (a, b) ->
                     (a[0] == b[0] ? b[1] - a[1] : a[0] -b[0]));
        int count = 0, cur =0;
        for (int[] i : intervals)
            if (cur < i[1]){
                cur = i[1];
                count++;
            }
        return count;
    }
}

Complexity:

Time complexity: O( nlogn)

Space complexity: O(1)