#992
Subarrays with K Different Integers
hard · verified · 67.6% accepted · 6,911 likes · top 74%
array · hash table · sliding window · counting
Description
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.
Example 1:
Input: nums = [1,2,1,2,3], k = 2
Output: 7
Explanation: 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
Explanation: Subarrays formed with exactly 3 different integers: [1,2,1,3], [2,1,3], [1,3,4].
Solution