0713 - Subarray Product Less Than K

0713 - Subarray Product Less Than K

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.

Examples

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.

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

Constraints

• 1 <= nums.length <= 3 * 104

• 1 <= nums[i] <= 1000

• 0 <= k <= 106

Java Solution

class Solution {
    public int numSubarrayProductLessThanK(int[] nums, int k) {
        if (k <= 1) return 0;
        int result = 0;
        int left = 0;
        int currentProduct = 1;
        
        for(int i = 0; i < nums.length; i++) {
            currentProduct *= nums[i];
            while(currentProduct >= k) currentProduct /= nums[left++];
            result += i - left + 1;
        }    
        return result;
    }
}