Divide Intervals Into Minimum Number of Groups
You are given a 2D integer array intervals where intervals[i] = [lefti, righti] represents the inclusive interval [lefti, righti].
You have to divide the intervals into one or more groups such that each interval is in exactly one group, and no two intervals that are in the same group intersect each other.
Return the minimum number of groups you need to make.
Two intervals intersect if there is at least one common number between them. For example, the intervals [1, 5] and [5, 8] intersect.
Example 1
5---------10
6---8
1-------5
2-3
1-----------------10Input
intervals = [[5,10],[6,8],[1,5],[2,3],[1,10]]Output
3We can divide the intervals into three groups, and it can be proven that fewer than 3 groups is not possible.
Example 2
1---3
5-6
8---10
11--13Input
intervals = [[1,3],[5,6],[8,10],[11,13]]Output
1None of the intervals overlap, so we can put all of them in one group.
Constraints
- 1 <= intervals.length <= 10^5
- intervals[i].length == 2
- 1 <= lefti <= righti <= 10^6