Subarrays with K Different Integers

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Problem Statement

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

A good array is an array where the number of different integers in that array is exactly k .

For example, [1,2,3,1,2] has 3 different integers: 1 , 2 , and 3 .

A subarray is a contiguous part of an array.

Examples

Example 1

Input: nums = [1,2,1,2,3], k = 2
Output: 7
Subarrays formed with exactly 2 different integers: [1,2], [2,1], [1,2], [2,3], [1,2,1], [2,1,2], [1,2,1,2]

Example 2

Input: nums = [1,2,1,3,4], k = 3
Output: 3
Subarrays formed with exactly 3 different integers: [1,2,1,3], [2,1,3], [1,3,4].

Constraints

1 <= nums.length <= 2 * 10 ^4

1 <= nums[i], k <= nums.length

😤

Hard

Difficulty

Topic Info

ModuleDSA

CategoryArray

Sub-topicHash Table