README.md

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.

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

Constraints:

• 1 <= intervals.length <= 1000
• intervals[i].length == 2
• 0 <= li < ri <= 105
• All the given intervals are unique.

Solutions (Rust)

1. Solution

impl Solution {
    pub fn remove_covered_intervals(intervals: Vec<Vec<i32>>) -> i32 {
        let mut intervals = intervals;
        let mut max_r = 0;
        let mut ret = intervals.len() as i32;
        intervals.sort_unstable_by_key(|interval| (interval[0], -interval[1]));

        for interval in intervals {
            if interval[1] <= max_r {
                ret -= 1;
            } else {
                max_r = interval[1];
            }
        }

        ret
    }
}