Learning On the Way

1288. Remove Covered Intervals

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.

def removeCoveredIntervals(self, intervals: List[List[int]]) -> int:
    res, longest = len(intervals), 0
    srtd = sorted(intervals, key = lambda i: (i[0], -i[1]))
    
    for _, end in srtd:
        if end <= longest:
            res -= 1
        else:
            longest = end
            
    return res