Remove Covered Intervals

Statement

Given an array of intervals, where each interval is represented as intervals[i] $= [l_i, r_i)$ (indicating the range from $l_i$ to $r_i$, inclusive of $l_i$ and exclusive of $r_i$), remove all intervals that are completely covered by another interval in the list. Return the count of intervals that remain after removing the covered ones.

Note: An interval $[a, b)$ is considered covered by another interval $[c, d)$ if and only if $c <= a$ and $b <= d$.

Constraints:

• $1 <=$ intervals.length $<= 1000$

• intervals[i].length $== 2$

• $0 <= l_i < r_i <= 10^5$

• All the given intervals are unique.

Examples