Given an array of positive integers nums and an integer k, return the number of contiguous subarrays where the product is strictly less than k.
nums = array of positive integers, k = threshold
count of qualifying subarrays
Example 1:
Input:
nums = [10,5,2,6] k = 100
Output:
8
Explanation:
The subarrays are [10],[5],[2],[6],[10,5],[5,2],[2,6],[5,2,6].