Class Solution


  • public class Solution
    extends Object
    2537 - Count the Number of Good Subarrays.

    Medium

    Given an integer array nums and an integer k, return the number of good subarrays of nums.

    A subarray arr is good if it there are at least k pairs of indices (i, j) such that i < j and arr[i] == arr[j].

    A subarray is a contiguous non-empty sequence of elements within an array.

    Example 1:

    Input: nums = [1,1,1,1,1], k = 10

    Output: 1

    Explanation: The only good subarray is the array nums itself.

    Example 2:

    Input: nums = [3,1,4,3,2,2,4], k = 2

    Output: 4

    Explanation: There are 4 different good subarrays:

    • [3,1,4,3,2,2] that has 2 pairs.

    • [3,1,4,3,2,2,4] that has 3 pairs.

    • [1,4,3,2,2,4] that has 2 pairs.

    • [4,3,2,2,4] that has 2 pairs.

    Constraints:

    • 1 <= nums.length <= 105
    • 1 <= nums[i], k <= 109
    • Constructor Detail

      • Solution

        public Solution()
    • Method Detail

      • countGood

        public long countGood​(int[] nums,
                              int k)