Package g2501_2600.s2580_count_ways_to_group_overlapping_ranges

Class Solution

  • public class Solution
extends Object
    2580 - Count Ways to Group Overlapping Ranges.

    Medium

    You are given a 2D integer array ranges where ranges[i] = [starti, endi] denotes that all integers between starti and endi (both inclusive ) are contained in the ith range.

    You are to split ranges into two (possibly empty) groups such that:

    • Each range belongs to exactly one group.
    • Any two overlapping ranges must belong to the same group.

    Two ranges are said to be overlapping if there exists at least one integer that is present in both ranges.

    • For example, [1, 3] and [2, 5] are overlapping because 2 and 3 occur in both ranges.

    Return the total number of ways to split ranges into two groups. Since the answer may be very large, return it modulo 109 + 7.

    Example 1:

    Input: ranges = [[6,10],[5,15]]

    Output: 2

    Explanation:

    The two ranges are overlapping, so they must be in the same group.

    Thus, there are two possible ways:

    • Put both the ranges together in group 1.

    • Put both the ranges together in group 2.

    Example 2:

    Input: ranges = [[1,3],[10,20],[2,5],[4,8]]

    Output: 4

    Explanation:

    Ranges [1,3], and [2,5] are overlapping. So, they must be in the same group.

    Again, ranges [2,5] and [4,8] are also overlapping. So, they must also be in the same group.

    Thus, there are four possible ways to group them:

    • All the ranges in group 1.

    • All the ranges in group 2.

    • Ranges [1,3], [2,5], and [4,8] in group 1 and [10,20] in group 2.

    • Ranges [1,3], [2,5], and [4,8] in group 2 and [10,20] in group 1.

    Constraints:

    • 1 <= ranges.length <= 105
    • ranges[i].length == 2
    • 0 <= starti <= endi <= 109

    • Constructor Detail

      • Solution

        public Solution()

    • Method Detail

      • countWays

        public int countWays​(int[][] ranges)