Description
Given an array of integers nums and an integer k, return the number of nice subarrays. A nice subarray is a subarray with exactly k odd numbers.
Examples
Input:
nums = [1,1,2,1,1], k = 3Output:
2Explanation:
[1,1,2,1] and [1,2,1,1] have 3 odds.
Input:
nums = [2,4,6,8], k = 1Output:
0Explanation:
The array contains only even numbers [2,4,6,8], so there are no odd numbers. Since the requirement is exactly 1 odd number and there are none, no subarrays can be nice.
Input:
nums = [3,5,7,2,4,9,11], k = 2Output:
9Explanation:
The odd numbers are at indices 0,1,2,5,6. Subarrays with exactly 2 odds: [3,5], [3,5,7], [3,5,7,2], [3,5,7,2,4], [5,7], [5,7,2], [5,7,2,4], [2,4,9,11], and [4,9,11]. Total: 9 nice subarrays.
Constraints
- •
1 ≤ nums.length ≤ 50000 - •
1 ≤ nums[i] ≤ 10^5