Counting Nice Subarrays With Sliding Window And Prefix Sums
The problem requires finding the number of subarrays in an integer array that contain exactly k odd numbers. A sliding window approach with prefix sums efficiently counts these "nice" subarrays.
1248. Count Number of Nice Subarrays Difficulty: Medium Topics: Array, Hash Table, Math, Sliding Window, Prefix Sum Given an array of integers nums and an integer k. A continuous subarray is called nice if there are k odd numbers on it. Return the number of nice sub-arrays. Example 1: Input: nums = [1,1,2,1,1], k = 3 Output: 2 Explanation: The only sub-arrays with 3 odd numbers are [1,1,2,1] and [1,2,1,1]. Example 2: Input: nums = [2,4,6], k = 1 Output: 0 Explanation: There are no odd numbers in the array. Example 3: Input: nums = [2,2,2,1,2,2,1,2,2,2], k = 2 Output: 16 Constraints: 1...