Medium
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
import java.util.PriorityQueue
import java.util.Queue
class Solution {
fun removeCoveredIntervals(intervals: Array<IntArray>): Int {
val q: Queue<IntArray> = PriorityQueue { a: IntArray, b: IntArray,
->
if (a[0] == b[0]) b[1] - a[1] else a[0] - b[0]
}
for (interval in intervals) {
q.offer(interval)
}
var prev = q.poll()
var count = 0
while (q.isNotEmpty()) {
val curr = q.poll()
if (curr[0] >= prev[0] && curr[1] <= prev[1]) {
count++
} else {
prev = curr
}
}
return intervals.size - count
}
}