Problem Statement

Given an array of integers nums, and an integer k, find the count of "good" subarrays within nums.

A subarray is considered "good" if it contains at least k pairs of elements (i, j) where i < j and nums[i] == nums[j].

A subarray is a contiguous sequence of elements in the original array.

Examples

• Example 1:

  • Input: nums = [2, 2, 2, 3, 3], k = 3
  • Expected Output: 3
  • Justification: There are 3 good subarrays that meet the criteria: [2, 2, 2, 3], [2, 2, 2, 3, 3], and [2, 2, 2]. Each of these subarrays has at least 3 pairs of equal elements.

• Example 2:

  • Input: nums = [4, 4, 4, 4], k = 6
  • Expected Output: 1
  • Justification: The only good subarray that meets the criteria is the entire array itself [4, 4, 4, 4], which contains 6 pairs of equal elements.

• Example 3:

  • Input: nums = [1, 2, 3, 1, 2], k = 2
  • Expected Output: 2
  • Justification: There is only 1 good subarray, which is [1, 2, 3, 1, 2]. It contains at least 2 pairs of equal elements.

Try it yourself

Try solving this question here: