Number of Intersecting Interval Pairs II | Sorting & Binary Search| Leetcode Contest | Leetcode 4057
Number of Intersecting Interval Pairs II - Video Solution
Watch 7 video solutions for Number of Intersecting Interval Pairs II, a medium level problem. This walkthrough by Sanyam IIT Guwahati has 598 views views. Want to try solving it yourself? Practice on FleetCode or read the detailed text solution.
Problem Statement
You are given a 2D integer array intervals of n elements, where intervals[i] = [starti, endi] represents the closed interval from starti to endi.
Return the number of pairs of indices (i, j) such that 0 <= i < j < n and intervals[i] and intervals[j] intersect.
Two intervals intersect if they have at least one point in common, including when they only share an endpoint.
Example 1:
Input: intervals = [[1,2],[2,3],[3,4]]
Output: 2
Explanation:
There are 2 intersecting interval pairs:
- Intervals
[1, 2]and[2, 3]intersect at the point 2. - Intervals
[2, 3]and[3, 4]intersect at the point 3.
Example 2:
Input: intervals = [[1,5],[2,4],[3,6]]
Output: 3
Explanation:
There are 3 intersecting interval pairs:
- The intersection of
[1, 5]and[2, 4]is[2, 4]. - The intersection of
[1, 5]and[3, 6]is[3, 5]. - The intersection of
[2, 4]and[3, 6]is[3, 4].
Example 3:
Input: intervals = [[1,2],[3,4],[5,6]]
Output: 0
Explanation:
There are no intersecting interval pairs. Hence, the answer is 0.
Constraints:
2 <= n == intervals.length <= 105intervals[i] = [starti, endi]0 <= starti <= endi <= 109