1288. Remove Covered Intervals

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

Description

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.

Example 1:

**Input:** intervals = [[1,4],[3,6],[2,8]]
**Output:** 2
**Explanation:** Interval [3,6] is covered by [2,8], therefore it is removed.

Example 2:

**Input:** intervals = [[1,4],[2,3]]
**Output:** 1

Example 3:

**Input:** intervals = [[0,10],[5,12]]
**Output:** 2

Example 4:

**Input:** intervals = [[3,10],[4,10],[5,11]]
**Output:** 2

Example 5:

**Input:** intervals = [[1,2],[1,4],[3,4]]
**Output:** 1

Constraints:

• 1 <= intervals.length <= 1000

• intervals[i].length == 2

• 0 <= li <= ri <= 105

• All the given intervals are unique.

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