Handle Intervals When Input Is Not Sorted

Problem: Interval Processing — Input Is Not Guaranteed to Be Sorted You are given a list of intervals intervals, where each interval is [l, r] with l <= r. Interval A = [l1, r1] is covered by interval B = [l2, r2] if l2 <= l1 and r1 <= r2. Given that the input is not sorted by start, remove all intervals that are covered by another interval and return the number of remaining intervals. Input n intervals: 1 <= n <= 2 * 10^5 Endpoints: 0 <= l <= r <= 10^9 Output The number of intervals remaining after removing covered intervals. Examples [[1,4],[3,6],[2,8]] -> 2 [[1,4],[2,3]] -> 1 [[0,10],[5,12]] -> 2 [[1,2],[1,4],[3,4]] -> 1 [[1,1],[1,2],[2,2],[0,3]] -> 1 Example Input [[1,4],[3,6],[2,8]] Output 2