Given an array of integers `nums` and an integer `k`, return the number of contiguous subarrays where the product of all the elements in the subarray is strictly less than `k`.

Example 1:

    Input: nums = [10,5,2,6], k = 100
    Output: 8
    Explanation: The 8 subarrays that have product less than 100 are:
    [10], [5], [2], [6], [10, 5], [5, 2], [2, 6], [5, 2, 6]
    Note that [10, 5, 2] is not included as the product of 100 is not strictly less than k.

Example 2:

    Input: nums = [1,2,3], k = 0
    Output: 0

Constraints:

- `1 <= nums.length <= 3 * 104`
- `1 <= nums[i] <= 1000`
- `0 <= k <= 106`