> For the complete documentation index, see [llms.txt](https://mayanktyagi3111.gitbook.io/interview-prep/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://mayanktyagi3111.gitbook.io/interview-prep/dynamic-programming/subarray-product-less-than-k.md).

# Subarray Product Less Than K

Your are given an array of positive integers `nums`.

Count and print the number of (contiguous) subarrays where the product of all the elements in the subarray is less than `k`.

**Example 1:**<br>

```
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.
```

**Note:**

`0 < nums.length <= 50000`.

`0 < nums[i] < 1000`.

`0 <= k < 10^6`.

```java
class Solution {
    public int numSubarrayProductLessThanK(int[] nums, int k) {
        if (k == 0)
            return 0;
        int count = 0;
        int product = 1;
        // Sliding window
        for (int start = 0, end = 0; end < nums.length; end++) {
            product *= nums[end];
            while (start <= end && product >= k) {
                product /= nums[start++];
            }
            count += end - start + 1;
        }
        return count;
    }
}
```